Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Coastal Virginia Offshore Wind Commercial Project Offshore of Virginia, 28656-28777 [2023-08924]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 86 (Thursday, May 4, 2023)]
[Proposed Rules]
[Pages 28656-28777]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-08924]



[[Page 28655]]

Vol. 88

Thursday,

No. 86

May 4, 2023

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 217





Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to the Coastal Virginia Offshore Wind 
Commercial Project Offshore of Virginia; Proposed Rule

Federal Register / Vol. 88 , No. 86 / Thursday, May 4, 2023 / 
Proposed Rules

[[Page 28656]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 230424-0110]
RIN 0648-BL74


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Coastal Virginia Offshore Wind 
Commercial Project Offshore of Virginia

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Proposed rule; proposed letter of authorization; request for 
comments.

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SUMMARY: NMFS has received a request from the Virginia Electric and 
Power Company, doing business as Dominion Energy Virginia (Dominion 
Energy), for Incidental Take Regulations (ITR) and an associated Letter 
of Authorization (LOA) pursuant to the Marine Mammal Protection Act 
(MMPA). The requested regulations would govern the authorization of 
take, by Level A harassment and Level B harassment, of small numbers of 
marine mammals over the course of 5 years (2024-2029) incidental to 
construction of the Coastal Virginia Offshore Wind Commercial (CVOW-C) 
project offshore of Virginia within the Bureau of Ocean Energy 
Management (BOEM) Commercial Lease of Submerged Lands for Renewable 
Energy Development on the Outer Continental Shelf (OCS) Lease Area OCS-
A 0483 (Lease Area) and associated Export Cable Routes. Project 
activities likely to result in incidental take include pile driving 
activities (impact and vibratory) and site assessment surveys using 
high-resolution geophysical (HRG) equipment. NMFS requests comments on 
its proposed rule. NMFS will consider public comments prior to making 
any final decision on the promulgation of the requested ITR and 
issuance of the LOA; agency responses to public comments will be 
summarized in the final notice of our decision. The proposed 
regulations, if promulgated, would be effective February 5, 2024, 
through February 4, 2029.

DATES: Comments and information must be received no later than June 5, 
2023.

ADDRESSES: Submit all electronic public comments via the Federal e-
Rulemaking Portal. Go to www.regulations.gov and enter NOAA-NMFS-2023-
0030 in the Search box. Click on the ``Comment'' icon, complete the 
required fields, and enter or attach your comments.
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. All comments received are a part of the 
public record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address), confidential business information, 
or otherwise sensitive information submitted voluntarily by the sender 
will be publicly accessible. NMFS will accept anonymous comments (enter 
``N/A'' in the required fields if you wish to remain anonymous).

FOR FURTHER INFORMATION CONTACT: Kelsey Potlock, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION: 

Availability

    A copy of Dominion Energy's Incidental Take Authorization (ITA) 
application and supporting documents, as well as a list of the 
references cited in this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. In case of 
problems accessing these documents, please call the contact listed 
above (see FOR FURTHER INFORMATION CONTACT).

Purpose and Need for Regulatory Action

    This proposed rule, if promulgated, would provide a framework under 
the authority of the MMPA (16 U.S.C. 1361 et seq.) to allow for the 
authorization of take of marine mammals incidental to construction of 
the CVOW-C project within the Lease Area and along export cable 
corridors to landfall locations in Virginia. NMFS received a request 
from Dominion Energy for 5-year regulations and a LOA that would 
authorize take of individuals of 21 species of marine mammals (seven 
species by Level A harassment and Level B harassment and 21 species by 
Level B harassment only), comprising 22 stocks, incidental to Dominion 
Energy's construction activities. No mortality or serious injury is 
anticipated or proposed for authorization. Please see below for 
definitions of harassment. Please see the Legal Authority for the 
Proposed Action section below for definitions of harassment, serious 
injury, and incidental take.

Legal Authority for the Proposed Action

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made, regulations are 
promulgated (when applicable), and public notice and an opportunity for 
public comment are provided.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, the availability of the species or stocks for taking for 
certain subsistence uses (referred to as ``mitigation''), and 
requirements pertaining to the mitigation, monitoring and reporting of 
the takings are set forth.
    As noted above, no serious injury or mortality is anticipated or 
proposed for authorization in this proposed rule. Relevant definitions 
of MMPA statutory and regulatory terms are included below:
     Take--to harass, hunt, capture, or kill, or attempt to 
harass, hunt, capture, or kill any marine mammal (16 U.S.C. 1362, 50 
CFR 216.3);
     Incidental taking--an accidental taking. This does not 
mean that the taking is unexpected, but rather it includes those 
takings that are infrequent, unavoidable or accidental (see 50 CFR 
216.103);
     Serious Injury--any injury that will likely result in 
mortality (50 CFR 216.3);
     Level A harassment--any act of pursuit, torment, or 
annoyance which has the potential to injure a marine mammal or marine 
mammal stock in the wild (16 U.S.C. 1362); and
     Level B harassment--any act of pursuit, torment, or 
annoyance which has the potential to disturb a marine mammal or marine 
mammal stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (16 U.S.C. 1362).

[[Page 28657]]

    Section 101(a)(5)(A) of the MMPA and the implementing regulations 
at 50 CFR part 216, subpart I, provide the legal basis for proposing 
and, if appropriate, issuing 5-year regulations and associated LOA. 
This proposed rule also establishes required mitigation, monitoring, 
and reporting requirements for Dominion Energy's proposed activities.

Summary of Major Provisions Within the Proposed Rule

    The major provisions of this proposed rule include:
     Authorize take of marine mammals by Level A harassment 
and/or Level B harassment. No mortality or serious injury of any marine 
mammal is proposed to be authorized;
     Establish a seasonal moratorium on pile driving during the 
months of highest North Atlantic right whale (Eubalaena glacialis) 
presence in the project area (November 1st-April 30th);
     Require both visual and passive acoustic monitoring by 
trained, NOAA Fisheries-approved Protected Species Observers (PSOs) and 
Passive Acoustic Monitoring (PAM) operators before, during, and after 
the in-water construction activities;
     Require training for all Dominion Energy personnel that 
would clearly articulate all relevant responsibilities, communication 
procedures, marine mammal monitoring and mitigation protocols, 
reporting protocols, safety, operational procedures, and requirements 
of the ITA and ensure that all requirements are clearly understood by 
all participating parties;
     Require the use of sound attenuation device(s) during all 
vibratory and impact pile driving of wind turbine generators (WTG) and 
offshore substations (OSS) foundation piles to reduce noise levels;
     Delay the start of pile driving if a North Atlantic right 
whale is observed at any distance by the PSO on the pile driving or 
dedicated PSO vessel;
     Delay the start of pile driving if other marine mammals 
are observed entering or within their respective clearance zones;
     Shut down pile driving (if feasible) if a North Atlantic 
right whale is observed or if other marine mammals enter their 
respective shut down zones;
     Conduct sound field verification monitoring during a 
minimum of three WTGs and all three OSS foundation installation events 
to measure in situ noise levels for comparison against the model 
results;
     Implement soft starts during impact pile driving and using 
the least hammer energy possible;
     Implement ramp-up for high-resolution geophysical (HRG) 
site characterization survey equipment prior to operating at full 
power;
     Implement various vessel strike avoidance measures;
     Increase awareness of North Atlantic right whale presence 
through monitoring of the appropriate networks and VHF Channel 16, as 
well as reporting any sightings to the sighting network;
     Implement Best Management Practices (BMPs) during 
fisheries monitoring research surveys and activities to reduce the risk 
of marine mammals being considered at-risk or of interacting with 
deployed gear; and
     Require frequent scheduled and situational reporting 
including, but not limited to, information regarding activities 
occurring, marine mammal observations and acoustic detections, and 
sound field verification monitoring results.

National Environmental Policy Act (NEPA)

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must evaluate the proposed action (i.e., promulgation of 
regulations and subsequent issuance of a 5-year LOA) and alternatives 
with respect to potential impacts on the human environment.
    Accordingly, NMFS proposes to adopt the BOEM Environmental Impact 
Statement (EIS), provided our independent evaluation of the document 
finds that it includes adequate information analyzing the effects of 
promulgating the proposed regulations and LOA issuance on the human 
environment. NMFS is a cooperating agency on BOEM's EIS. BOEM's CVOW-C 
Draft Environmental Impact Statement for Commercial Wind Lease OCS-A 
0483 (DEIS), was made available for public comment through a Notice of 
Availability on December 16, 2022 (87 FR 77135), available at https://www.boem.gov/renewable-energy/state-activities/CVOW-C. The DEIS had a 
60-day public comment period; the comment period was open from December 
16, 2022 to February 14, 2023. Additionally, BOEM held three virtual 
public hearings on January 25, 2023, January 31, 2023, and February 2, 
2023.
    Information contained within Dominion Energy's ITA application and 
this proposed rule collectively provide the environmental information 
related to these proposed regulations and associated 5-year LOA for 
public review and comment. NMFS will review all comments submitted in 
response to this proposed rule prior to concluding our NEPA process or 
making a final decision on the requested 5-year ITR and associated LOA.

Fixing America's Surface Transportation Act (FAST-41)

    This project is covered under Title 41 of the Fixing America's 
Surface Transportation Act, or ``FAST-41.'' FAST-41 includes a suite of 
provisions designed to expedite the environmental review for covered 
infrastructure projects, including enhanced interagency coordination as 
well as milestone tracking on the public-facing Permitting Dashboard. 
FAST-41 also places a 2-year limitations period on any judicial claim 
that challenges the validity of a Federal agency decision to issue or 
deny an authorization for a FAST-41 covered project (42 U.S.C. 4370m-
6(a)(1)(A)).
    Dominion Energy's proposed project is listed on the Permitting 
Dashboard. Milestones and schedules related to the environmental review 
and permitting for the CVOW-C project can be found at https://www.permits.performance.gov/permitting-project/coastal-virginia-offshore-wind-commercial-project.

Summary of Request

    On February 16, 2022, NMFS received a request from Dominion Energy 
for the promulgation of a 5-year ITR and issuance of an associated LOA 
to take marine mammals incidental to construction activities associated 
with the CVOW-C project offshore of Virginia in the Lease Area and 
associated export cable routes. Dominion Energy's request is for the 
incidental, but not intentional, take of a small number of 21 marine 
mammal species (comprising 22 total stocks) by Level B harassment and 
by Level A harassment for seven marine mammal species, comprising 7 
stocks. Neither Dominion Energy nor NMFS expects serious injury or 
mortality to result from the specified activities, and Dominion Energy 
did not request and NMFS is not proposing to authorize mortality or 
serious injury of any marine mammals species or stock.
    In response to our comments and following extensive information 
exchanges with NMFS, Dominion Energy submitted a final, revised 
application on August 5, 2022, that NMFS deemed adequate and complete 
on August 12, 2022. The final version of the application is available 
on NMFS' website at https://www.fisheries.noaa.gov/action/incidental-
take-authorization-dominion-

[[Page 28658]]

energy-virginia-construction-coastal-virginia.
    On September 15, 2022, NMFS published a notice of receipt (NOR) of 
the adequate and complete application in the Federal Register (87 FR 
56634), requesting comments and soliciting information related to 
Dominion Energy's request during a 30-day public comment period. During 
the NOR public comment period, NMFS received one public comment letter 
from another Federal agency (the United States Geological Survey 
(USGS)) and one public comment letter from an environmental non-
government organization (the Southern Environmental Law Center). NMFS 
has reviewed all submitted material and has taken these into 
consideration during the drafting of this proposed rule.
    In June 2022, Duke University's Marine Spatial Ecology Laboratory 
released updated habitat-based marine mammal density models (Roberts et 
al., 2016; Robert and Halpin, 2022). Because Dominion Energy applied 
marine mammal densities to their analysis in their application, 
Dominion Energy submitted a final Updated Density and Take Estimation 
Memo (herein referred to as Updated Density and Take Estimation Memo) 
on January 10, 2023 that included marine mammal densities and take 
estimates based on these new models which NMFS posted on our website in 
May 2023.
    In January 2023, BOEM informed NMFS that the proposed activity had 
changed from what is presented in the adequate and complete MMPA 
application. Specifically, the changed proposed activity involved the 
reduction of maximum WTGs built (from 205 to 202 WTGs) as under the 
original Project Design Envelope (PDE) and the OSSs would be located in 
the vessel transit routes. Under the 202 build-out, three WTGs would be 
removed and the three OSSs would be shifted into these WTG positions. 
However, in late-January 2023, Dominion Energy confirmed that their 
Preferred Layout of 176 WTGs is the base case for construction, but 
that they could possibly need up to 7 WTGs re-piled in alternate 
positions due to unstable sediment conditions, which could necessitate 
up to 183 independent piling events. WTG positions have been removed 
from consideration for one or more of the following reasons: 
impracticable due to foundation technical design risk, shallow gas 
presence, commercial shipping and navigation risk concerns, erosion 
risk, and presence of a designated fish haven. Based on the information 
provided, NMFS carried forward the analysis assuming a total build-out 
of 176 WTGs plus seven re-piled WTGs (a total of 183 independent piling 
events for WTGs) and the 3 originally planned OSSs. Due to the 
significant reduction of turbines from the original proposed action 
found in the adequate and complete ITA application (reduction of 
approximately 14 percent), Dominion Energy, in consultation with NMFS, 
provided an updated proposed action summary, revised exposure 
estimates, revised take requests, and an updated piling schedule in 
mid-February 2023 (herein referred to as the Revised Proposed Action 
Memo). NMFS posted this to our website in May 2023.
    NMFS has previously issued six Incidental Harassment Authorizations 
(IHAs) to Dominion Energy. Two of those IHAs, issued in 2018 (83 FR 
39062; August 8, 2018) and 2020 (85 FR 30930, May 21, 2020) supported 
the development of the Coastal Virginia Offshore Wind project, known as 
the CVOW Pilot Project (wherein two turbines were constructed). The 
remaining four IHAs (two of which were modified IHAs) were high 
resolution site characterization surveys within and around the CVOW-C 
Lease Area (see 85 FR 55415, September 8, 2020; 85 FR 81879, December 
17, 2020 (modified 2020 IHA); 86 FR 21298, April 22, 2021 (modified 
2021 IHA); and 87 FR 33730, June 3, 2022).
    To date, Dominion Energy has complied with all the requirements 
(e.g., mitigation, monitoring, and reporting) of the previous IHAs. 
Information regarding Dominion Energy's take estimates and monitoring 
results may be found in the Estimated Take section. The monitoring 
reports can be found on NMFS' website, along with the relevant, 
previously issued IHAs: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable.
    On August 1, 2022, NMFS announced proposed changes to the existing 
North Atlantic right whale vessel speed regulations (87 FR 46921; 
August 1, 2022) to further reduce the likelihood of mortalities and 
serious injuries to endangered right whales from vessel collisions, 
which are a leading cause of the species' decline and a primary factor 
in an ongoing Unusual Mortality Event. Should a final vessel speed rule 
be issued and become effective during the effective period of this ITR 
(or any other MMPA incidental take authorization), the authorization 
holder would be required to comply with any and all applicable 
requirements contained within the final rule. Specifically, where 
measures in any final vessel speed rule are more protective or 
restrictive than those in this or any other MMPA authorization, 
authorization holders would be required to comply with the requirements 
of the rule. Alternatively, where measures in this or any other MMPA 
authorization are more restrictive or protective than those in any 
final vessel speed rule, the measures in the MMPA authorization would 
remain in place. The responsibility to comply with the applicable 
requirements of any vessel speed rule would become effective 
immediately upon the effective date of any final vessel speed rule and, 
when notice is published on the effective date, NMFS would also notify 
Dominion Energy if the measures in the speed rule were to supersede any 
of the measures in the MMPA authorization such that they were no longer 
required.

Description of the Specified Activities

Overview

    Dominion Energy's CVOW-C project would allow the Commonwealth of 
Virginia to meet its clean energy goal of achieving 100 percent clean 
energy by 2045 through the implementation of up to 5,200 megawatts (MW) 
of offshore wind-generated energy, as established in the Virginia Clean 
Economy Act (HB 1526/SB 851; https://lis.virginia.gov/cgi-bin/legp604.exe?201+ful+CHAP1193+hil&201+ful+CHAP1193+hil). To achieve 
this, Dominion Energy has proposed to construct and operate CVOW-C in 
state and Federal waters of the Atlantic Ocean in the Lease Area that 
is capable of producing between 2,500 and 3,000 MW of renewable energy 
and would be the largest offshore wind project in the United States at 
the time of its construction.
    Dominion Energy's precursor pilot project (i.e., CVOW Pilot 
Project) was a 12 MW, two-turbine test project and the first to be 
installed in Federal waters. Designed as a research/test project, the 
two turbines associated with the CVOW Pilot Project became operational 
in October 2020 approximately 27 miles (mi; 43.45 kilometers (km)) off 
of Virginia Beach, Virginia. Information on this Pilot Project was used 
to inform the proposed CVOW-C project. More information on the Pilot 
Project can be found on BOEM's website (https://www.boem.gov/renewable-energy/state-activities/coastal-virginia-offshore-wind-project-cvow) 
and in the IHA authorized by NMFS in May 2020 for BOEM Lease Area OCS-
A-0497 (https://www.fisheries.noaa.gov/action/incidental-take-authorization-dominion-energy-virginia-offshore-wind-construction-activities).

[[Page 28659]]

    CVOW-C would consist of several different types of permanent 
offshore infrastructure, including up to 176 wind turbine generators 
(WTGs; e.g., such as the Siemens Gamesa SG-14-222 DD 14-MW model with 
power boost technology potentially allowing up to 14.7-MW, equating to 
a total of 2,587.2-MW for full build-out), three offshore substations 
(OSS), and inter-array and substation interconnect cables. Dominion 
Energy plans to install WTG and OSS foundations via a joint-
installation approach using both vibratory and impact pile driving. 
Dominion Energy would also conduct the following supporting activities: 
temporarily install and remove, by vibratory pile driving, up to nine 
cofferdams to connect the offshore export cables to onshore facilities; 
temporarily install and remove, by impact pile driving and a pipe 
thruster, respectively, up to 108 goal posts (12 goal posts for each of 
nine Direct Pipe locations) to guide casing pipes; permanently install 
scour protection around WTG and OSS foundations; permanently install 
and perform trenching, laying, and burial activities associated with 
the export cables from the OSSs to shore-based switching and sub-
stations and WTG inter-array cables; annually perform, using active 
acoustic sources with frequencies of less than 180 kilohertz (kHz), 
high-resolution vessel-based site characterization geophysical (HRG) 
surveys; and intermittently perform, via a modified dredge, and a pot-
based monitoring approach, fishery monitoring surveys to enhance 
existing data for specific benthic and pelagic species of concern. 
Vessels would transit within the project area and between ports and the 
wind farm to transport crew, supplies, and materials to support 
construction activities. All offshore cables would be connected to 
onshore export cables at the sea-to-shore transition point via 
trenchless installation (i.e., underground tunneling utilizing micro 
tunnel boring installation methodologies) in a parking lot found west 
of the firing range at the State Military Reservation located in 
Virginia Beach, Virginia. From the sea-to-shore transition point, 
onshore underground export cables are then connected in series to 
switching stations/substations, overhead transmission lines, and 
ultimately to the grid connection.
    Marine mammals exposed to elevated noise levels during impact and 
vibratory pile driving and site characterization surveys may be taken, 
by Level A harassment and/or Level B harassment, depending on the 
specified activity.

Dates and Duration

    Dominion Energy anticipates that activities with the potential to 
result in incidental take of marine mammals would occur throughout all 
five years of the proposed regulations which, if issued, would be 
effective from February 5, 2024, through February 4, 2029. Based on 
Dominion Energy's proposed schedule, the installation of all permanent 
structures would be completed by the end of October 2025. More 
specifically, the installation of WTG foundations is expected to occur 
between May 1st-October 31st of 2024 and 2025, over approximately 12 
months (6 months within each year). OSS jacket foundations using pin 
piles would be installed between May 1st-October 31st, 2024 and 2025. 
However, delays due to weather or other unanticipated and unforeseen 
events may require Dominion Energy to install some foundations in 2026. 
If this occurs, foundation installation would occur between the 
predetermined pile driving seasonal window (May 1st-October 31st in 
2026) and occur over 6 months. However, as this would represent a shift 
in the schedule, rather than additional piles being installed, the 
proposed activities would still maintain the same amount of take 
proposed for authorization, both annual maximum and five-year total. 
The temporary structures used for nearshore cable landfall construction 
(i.e., temporary cofferdams and temporary goal posts) would be 
installed and subsequently removed between May 1st-October 31st, 2024. 
Lastly, Dominion Energy anticipates HRG survey activities using 
boomers, sparker, and Compressed High-Intensity Radiated Pulses 
(CHIRPs) to occur annually and across the five-year period. Up to 65 
days of surveys are planned in 2024, 249 are planned in 2025, 58 are 
planned in 2026, and 368 survey days are planned annually in each of 
2027 and 2028. No surveys are planned to occur in 2029. These surveys 
may occur across the entire CVOW-C Lease Area and Export Cable Routes 
and may take place at any time of year.
    Dominion Energy has provided a schedule for all of their proposed 
construction activities (Table 1). Based on the schedule presented, no 
activities (installation, removal, or HRG surveys) are planned to occur 
in 2029, even though part of this year would fall within the five-year 
effective period of the proposed regulations. This table also presents 
a breakdown of the timing and durations of the activities proposed to 
occur during the construction and operation of the CVOW-C project.

         Table 1--CVOW-C's Construction and Operations Schedule During the Effective Period of the LOA a
----------------------------------------------------------------------------------------------------------------
             Project activity                     Expected timing            Expected duration (approximate)
----------------------------------------------------------------------------------------------------------------
Scour Protection Pre-Installation........  Q2 through Q4 of 2024.......  9 months.
                                           Q2 through Q4 of 2025.......  9 months.
WTG Foundation Installation \b\ \e\......  Q2 through Q4 of 2024.......  6 months.
                                           Q2 through Q4 of 2025.......  6 months.
Scour Protection Post-installation.......  Q2 through Q4 of 2024.......  9 months.
                                           Q2 through Q4 of 2025.......  9 months.
OSS Foundation Installation \b\ \e\......  Q2 through Q4 of 2024.......  6 months.
                                           Q2 through Q4 of 2025.......  6 months.
Cable Landfall Construction (Goal Posts    Q1 through Q4 of 2024.......  6 months.
 and Cofferdams) \h\.
HRG Surveys \c\ \d\......................  Q1 2024 through Q4 2028.....  Any time of year.
Site Preparation.........................  Q1 2024 through Q2 2024.....  6 months.
Inter-array Cable Installation...........  Q2 2025 through Q4 2026.....  19 months.
Export Cable Installation................  Q3 2024 through Q3 2025.....  14 months.
Fishery Monitoring Surveys: \f\ \g\

[[Page 28660]]

 
    Surf Clam............................  Q2 2023.....................  1 week.
    Whelk................................  Q2 2023 through Q1 2025.....  24 months.
    Black Sea Bass.......................  Q2 2023 through Q1 2025.....  24 months.
----------------------------------------------------------------------------------------------------------------
Note: ``Q1, Q2, Q3, and Q4'' each refer to a quarter of the year, starting in January and comprising 3 months
  each. Therefore, Q1 represents January through March, Q2 represents April through June, Q3 represents July
  through September, and Q4 represents October through December.
\a\ While the effective period of the proposed regulations would extend a few months into 2029, no activities
  are proposed to occur in 2029 by Dominion Energy so these were not included in this table.
\b\ Activities would only occur between May 1st through October 31st annually.
\c\ Activities would begin in February 2024, upon the issuance of a LOA, and continue through construction and
  post-construction.
\d\ For HRG surveys, Dominion Energy anticipates up to 65 days of surveys would occur during the pre-
  construction period (2024), up to 307 days during the primary construction years (2025 and 2026), and up to
  736 days would be needed during the post-construction years (2027 and 2028) with a 50/50 split of 368 days
  each year. No surveys are planned for 2029.
\e\ Dominion Energy anticipates that all WTGs and OSS foundations will be installed by October 31st, 2025;
  however, unanticipated delays may require some foundation pile driving to occur in 2026.
\f\ Some fishery monitoring survey activities are planned prior to February 2024 but are not included here as
  they would not occur during the effective dates of the ITR and LOA.
\g\ Dates displayed here are for field work, as that would be the only component that could impact marine
  mammals.
\h\ Although cable landfall activities are anticipated to occur over 9-12 months total, activities capable of
  harassing marine mammals would only occur for the specified duration described here as other activities
  necessary for landfall construction (i.e., area preparation, material transportation, etc.) would also occur.

    Dominion Energy anticipates that the first 40 WTGs would become 
operational in 2025, after foundation installation is completed and 
after all necessary components (such as array cables, OSSs, export 
cables routes, and onshore substations) are installed. Up to 120 
additional WTGs would be commissioned/operational in 2026. Dominion 
Energy anticipates that all turbines would be commissioned by 2027, 
with the last 16 being operational that year.

Specific Geographic Region

    Dominion Energy would construct the CVOW-C project in Federal and 
state waters offshore of Virginia within the BOEM Lease Area OCS-A 0483 
and associated Export Cable Routes (Figure 1). The Lease Area covers 
approximately 456.5 km\2\ (112,799 acres) and is located approximately 
27 mi (43.5 km) east of Virginia Beach, Virginia. The water depths in 
the Lease Area range from 19.9 m to 38.1 m (65 to 125 ft) while water 
depths along the Export Cable Routes range from 0 to 28 m (0 to 92 ft). 
Cable landfall construction work would be conducted in shallow water 
(temporary cofferdams would be in water 3.3 m (10.83 ft) deep, and the 
goal posts would be at depths of 22.9 m (75 ft)). Sea surface 
temperatures range from 32 to 88 degrees Fahrenheit ([deg]F; 0 to 31 
degrees Celsius ([deg]C)) while the depth-averaged annual water 
temperature is 56.39 [deg]F (13.55 [deg]C) (NOAA n.d.B). Cables would 
come ashore adjacent to the western boundary of the State Military 
Reservation firing range in Virginia Beach.
    Dominion Energy's specified activities would occur along a portion 
of the Mid-North Atlantic continental shelf that experiences various 
concurrent processes that shape the overall geology of the region. 
These processes include glacio-eustatic sea level change (i.e., a 
change in sea level due to the uptake or release of water from glaciers 
and polar ice), drainage from Chesapeake Bay, and storm-related effects 
to sedimentation. The basin structure in which the CVOW-C project area 
is located, the Baltimore Canyon Trough, is oriented northeast to 
southwest and consists of a wedge of sediments that thicken to the east 
(Dominion Energy, 2023).
    The Mid-Atlantic Bight, where the CVOW-C project would be located, 
spans from Cape Hatteras, North Carolina to Cape Cod, Massachusetts and 
continues to extend into the west Atlantic to the 100-m isobath. The 
oceanographic conditions along the Mid-Atlantic Bight are comparable to 
the conditions found along the Mid-Atlantic East Coast, where summer 
months are warmer and winter months are milder. The area is known for 
its high levels of primary productivity, specifically in the nearshore 
and estuarine regions, where coastal phytoplankton tend to bloom in the 
winter and summer. Given the proximity to the continental shelf, this 
area forms an important habitat for various benthic and fish species, 
as well as forms important habitat for fin whales, humpback whales, 
North Atlantic right whales, and other large whales as they migrate 
through the area. The CVOW-C project area is located within the Mid-
Atlantic Bight and relatively flat with ``very gentle to gentle 
slopes'', as described by the BOEM classification found in the CVOW-C 
Construction and Operations Plan (COP) (Dominion Energy, 2023). In the 
Export Cable Routes, the seafloor slopes are less than 1 degree (``very 
gentle'' based again on the BOEM classification; Dominion Energy, 
2023). The most significant slopes can be found on the flanks of 
morphological features and other topographic highs where the seabed 
gradient ranges up to 4 degrees (Dominion Energy, 2023). The most 
prominent seabed features with the project area are pronounced sand 
ridges that create a ridge and swale topography. In the northeastern 
portion of the project area, the heights of the sand ridges are lower, 
topographic variation across the ridges is reduced, seafloor bathymetry 
is deeper, and water depths are less variable.
    A complete mapping of the seabed has identified a low number of 
boulders present on the seafloor (Dominion Energy, 2023). Only 10 
boulders and 110 seabed targets interpreted as possible boulders have 
sizes greater than 1 m (3 ft). No patterns were identified in the 
location of boulders across the Lease Area and Export Cable Routes.
    The seafloor in the CVOW-C project area is dynamic and changes over 
time due to current, tidal flows, and wave conditions. The benthic 
habitat of the project area contains a variety of seafloor substrates, 
physical features, and associated benthic organisms. The soft bottom 
sediments in the project area are reflective of the rest of the Mid-
Atlantic Bight region, and characterized

[[Page 28661]]

by fine sand as well as gravel and silt/sand mixes (Milliman, 1972; 
Steimle and Zetlin, 2000). Underwater soils in the area are known to be 
soft, with two specific soils noted that could increase the risk of 
pile run (Dominion Energy, 2023). The presence of bedforms, mobile 
sediments, and potential for scouring exist in the project area 
(Dominion Energy, 2023). However, the paleochannel strata is not 
considered a weak layer due to stiffness and strength values being 
within normal ranges and as such, is not considered a hazard to cable 
or foundation installation (Dominion Energy, 2023). The dominant 
benthic fauna within the Lease Area are annelids, mollusks, and 
arthropods (Dominion Energy, 2023).
    Additional information on the underwater environment's physical 
resources can be found in CVOW-C's COP (Dominion Energy, 2023) 
available at https://www.boem.gov/renewable-energy/state-activities/coastal-virginia-offshore-wind-project-construction-and.
BILLING CODE 3510-22-P

[[Page 28662]]

[GRAPHIC] [TIFF OMITTED] TP04MY23.081


[[Page 28663]]


BILLING CODE 3510-22-C
Figure 1--The CVOW-C Project Area

Detailed Description of Specified Activities

    Below, we provide detailed descriptions of Dominion Energy's 
activities, explicitly noting those that are anticipated to result in 
the take of marine mammals and for which incidental take authorization 
is requested. Additionally, a brief explanation is provided for those 
activities that are not expected to result in the take of marine 
mammals.
WTG and OSS Foundations
    Dominion Energy proposes to install up to 176 WTGs on monopile 
foundations and 3 OSSs on jacket foundations. They anticipate all WTG 
foundations could be installed between May 1st through October 31st in 
2024 and 2025, over the course of six months in each year. However, it 
may be possible that monopile installation associated with the WTG 
foundations would need to continue into a third year (2026), depending 
on construction logistics and local and environmental conditions that 
may influence Dominion Energy's ability to maintain the planned 
construction schedule. If this is determined to be necessary, WTG 
foundations would only be installed between May 1st through September 
30th of 2026. However, this schedule shift would not change NMFS' 
proposed determinations as the total number of piles would remain the 
same. While this shift is unlikely to occur, the proposed rulemaking 
does retain flexibility in addressing unforeseen circumstances. 
However, all foundations would be installed during the effective period 
of this proposed rule, if issued. OSS jacket foundations would most 
likely be installed in August 2024; however, they could be installed 
anytime between May 1st through October 31st. For both types of 
foundations, Dominion Energy has committed to not installing from 
November 1st through April 30th, annually.
    A WTG monopile foundation typically consists of a single steel 
tubular section, with several sections of rolled steel plate welded 
together. Each monopile would have a maximum diameter tapering from 7.5 
m (24.6 ft) at the top to 9.5 m (31 ft) at the seafloor (collectively 
referred to as a 9.5/7.5-m monopile). WTGs would be spaced 
approximately 0.75 nautical miles (nm; 1.39 km) in an east-west 
direction and 0.93 nm (1.72 km) in a north-south direction and will 
have an average penetration depth of 42 m (138 ft; between 30 m and 46 
m per Attachment Z-3 of Appendix A in Dominion Energy's ITA 
application). Although only 176 WTGs would be installed, seven 
foundations may need to be re-installed at a different location; hence 
Dominion Energy has accounted for up to 183 WTG individual piling 
events in its analysis, which we have carried forward with in this 
proposed rule.
    Each OSS installed by Dominion Energy would be supported by a 
jacket foundation. A piled jacket foundation is formed by a steel 
lattice construction (comprising tubular steel members and welded 
joints) secured to the seabed by means of hollow steel pin piles 
attached to the jacket. Each jacket foundation would consist of up to 
four pin piles. In total, Dominion Energy would install up to 3 OSSs 
for a total of 12 pin piles. Up to two pin piles would be installed per 
day. Pin piles will have a maximum diameter of 2.8 m (9.2 ft) each and 
will be installed vertically. The maximum penetration depth of each pin 
pile would be 82 m (269 ft).
    Given the project area's soil conditions, the installation of both 
WTG monopile foundations and OSS jacket foundations would necessitate 
the use of both vibratory and impact pile driving to avoid pile run 
(also known as ``punch-through''). Pile run can occur when a monopile 
or a pin pile rapidly penetrates in an uncontrolled manner through a 
weak layer of soil, due to the soil resistance being lower than the 
weight of the pile and hammer (transferring impulsive energy to the 
pile). Pile runs can occur instantaneously and through a depth of 
meters to dozens of meters. A pile run incident can have severe 
negative consequences, both for the safety of personnel aboard the 
installation vessel and significant risk of damage to equipment. To 
mitigate this risk, Dominion Energy would first perform vibratory 
hammering, which would allow for a more controllable installation 
process when installing piles in soft sediments as the vibrohammer is 
directly in contact with the pile (see Figures 2 through 5 in Dominion 
Energy's ITA application), as opposed to installation using the impact 
hammer (see Figures 6 and 7 in Dominion Energy's ITA application). Once 
the pile run risk depth has been passed, the method of installation 
would transition from a vibratory hammer to an impact hammer. It is 
anticipated the transition from a vibratory hammer to an impact hammer 
would require approximately 1.2 hours wherein no pile driving would 
occur. Once installation of the monopile and/or pin pile is complete, 
the pile driving vessel would move to the next installation location. 
While Dominion Energy states that not all piles will require the use of 
the vibrohammer in conjunction with the impact hammer, it was 
considered more conservative to analyze all installed piles using this 
dual approach as it is not yet known how many would require the dual 
installation method. No concurrent pile driving at multiple locations 
would occur.
    Per monopile, use of the vibrohammer is estimated to occur for 
approximately 30 to 60 minutes (depending on if the pile uses a 
standard driving or hard-to-drive scenario, respectively) to firmly 
stabilize the foundation pile. A 72 minute (1.2 hour) pause to allow 
for the vibratory hammer to be exchanged with an impact hammer would 
occur. Then, the impact hammer would be used for approximately three 
hours (constituting approximately 3 hours for 3,240-3,720 total hammer 
strikes, with more strikes needed if the pile is considered difficult 
to install). A joint standard and hard-to-drive scenario (Scenario 3) 
for the installation of up to two monopiles in a single day may require 
up to 90 minutes of vibratory pile driving followed by up to 6,960 
hammer strikes. In all situations, the impact hammer would drive the 
pile until it reaches its target embedment depth (approximately 42 m 
(138 ft) for monopiles). The three possible WTG monopile installation 
scenarios are laid out in Table 2 below:

               Table 2--WTG Monopile Scenarios With Scenario-Specific Installation Characteristics
----------------------------------------------------------------------------------------------------------------
                                           Number of WTG   Maximum vibratory
         Installation scenario               monopiles      hammer duration    Maximum impact     Impact hammer
                                             installed         (minutes)       hammer strikes      energy (kJ)
----------------------------------------------------------------------------------------------------------------
Scenario 1 (Standard)..................                 1                 60             3,240             4,000
Scenario 2 (Hard-to-drive).............                 1                 30             3,720             4,000

[[Page 28664]]

 
Scenario 3 (Standard and Hard-to-drive)                 2                 90             6,960             4,000
----------------------------------------------------------------------------------------------------------------

    For pin piles, vibratory pile driving is anticipated to require 
approximately 120 minutes (2 hours), a 72 minute (1.2 hours) pause in 
activities, and then continue with impact pile driving using a hammer 
energy up to 3,000 kJ, resulting in a total estimate of 15,210 hammer 
strikes. As with WTG foundations, the impact hammer would drive the pin 
pile until it reaches its target embedment depth (approximately 82 m 
(269 ft) for pin piles). A maximum of two pin piles would be driven per 
day. Each OSS jacket foundation would take approximately five days to 
install with a total of 30 days needed for the completion of all three 
OSSs (n=3) with all of their pin piles (n=12). This 30-day period does 
include periods of non-pile driving time where other activities related 
to the jacket foundations may be installed.
    The current construction schedule assumes foundation installation 
would occur in 2024 and 2025; however, as previously discussed in the 
Dates and Duration section, limited installation of WTGs may need to be 
installed in 2026 if the project falls off of the construction 
schedule. Given an estimated installation schedule, Dominion Energy 
expects that up to 95 monopile foundations would be installed in 2024 
and up to 88 monopiles would be installed in 2025. If pile driving must 
occur in this 3rd year, installation would only occur across a five 
month period (May 1st through September 30th, 2026). All WTG and OSS 
foundation installation would occur during daylight hours only. The 
only exception would be if, for safety reasons, ceasing pile driving 
activities would compromise both the health of humans and the 
environment or if ceasing the pile driving would cause instability and 
integrity concerns on the project. In most cases, one pile would be 
installed per day, although two may be installed during some months. No 
concurrent pile driving is planned or proposed to occur. The same 
exception described above for WTG foundations applies to OSS 
foundations where integrity or safety concerns may necessitate the pile 
to be finished after sunset. The proposed WTG and OSS pile driving 
schedule can be found in Table 3 below that describes the construction 
schedule on both an annual and monthly basis.

               Table 3--Proposed Pile Driving Schedule for the CVOW-C Project of 176 WTGs and 3 OSSs, Plus 7 Possible WTG Re-Piling Events
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                          Days when two
                                                                              Total proposed number of  Number of hard-    Number of    monopiles may be
                Year \b\                                Month                          piles            to-drive piles  standard piles    installed per
                                                                                                                                               day
--------------------------------------------------------------------------------------------------------------------------------------------------------
2024...................................  May...............................  18.......................               5              13                 1
                                         June..............................  25.......................               6              19                 6
                                         July..............................  26.......................               7              19                 6
                                         August............................  2 monopiles; 12 pin piles               1               1                 1
                                         September.........................  13.......................               3              10                 0
                                         October...........................  11.......................               1              10                 0
                                                                            ----------------------------------------------------------------------------
    2024 Annual Total..................  ..................................  95 monopiles; 12 pin                   23              72                14
                                                                              piles \a\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
2025...................................  May...............................  16.......................               6              10                 1
                                         June..............................  22.......................               8              14                 6
                                         July..............................  24.......................               8              16                 6
                                         August............................  20.......................               6              14                 6
                                         September.........................  5........................               2               3                 0
                                         October...........................  1........................               1               0                 0
                                                                            ----------------------------------------------------------------------------
    2025 Annual Total..................  ..................................  88 monopiles.............              31              57                19
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Included only if seven re-piling events are necessary.
\b\ While Dominion Energy plans for all pile driving to be completed by the end of the 2025 piling period (end of October 2025), unforeseen
  circumstances may necessitate that piling would need to continue into 2026. While not planned or anticipated, the proposed rule would allow for
  flexibility in shifting certain activities with the understanding that the maximum estimated takes would not exceed the amount described in the
  proposed rule.

Cable Landfall Construction
    To support the connection of the offshore cable with the onshore 
cable, Dominion Energy would install both temporary goal posts and 
temporary cofferdams approximately 1,000 m (3,281 ft) offshore of the 
State Military Reservation in Virginia Beach, Virginia. These 
activities are two components of a broader set of activities conducted 
during cable landfall construction. The goal posts and cofferdams would 
support work associated with installing casing pipes housing the export 
cables. Dominion Energy would install the 9 casing pipes approximately 
50 ft apart from each other at the cable landfall construction site 
using a Trenchless Installation approach. Using a tunneling approach 
similar to horizontal directional drilling (HDD), a boring machine 
would excavate the ground while simultaneously pushing strings of steel 
casing pipes along umbilical lines

[[Page 28665]]

using rollers or other movable support structures behind the boring 
drill using a pipe thruster machine. The export cables would be fed 
through these pushed casing pipes, which would terminate at an onshore 
exit point located west of the firing range from the State Military 
Reservation.
    Temporary goal posts (made up of 42-in diameter steel pipe piles) 
would be installed between each exit location and would be used to 
guide the progress and movement of the casing pipes and to provide 
lateral stability. Temporary cofferdams are used to aid cable pull in 
as the cable is fed through the underground tunnel (located 6.6 ft (2 
m) below the seabed). A technical description of the Trenchless 
Installation approach can be found in Section 1 of Dominion Energy's 
ITA application.
    Trenchless installation requires the use of extensive equipment 
that would be staged at the onshore location for the cable. However, 
only the equipment required to extract the boring device, post-
tunneling, is temporarily staged at the onshore exit location. Despite 
the extensive equipment necessary for this activity (see the ITA 
application for details), most of it is not expected to result in the 
take of marine mammals as the source levels are all generally very low. 
Even the pipe thruster does not vibrate or make noise and simply pushes 
the pipe forward with the boring device. Because of this, only the 
aspects for cable landfall construction that could cause the take of 
marine mammals (i.e., impact and vibratory pile driving) is discussed 
further. The aspects of landfall construction that could cause the 
harassment of marine mammals is specifically due to the installation of 
steel pipe piles for goal posts and the installation and removal of 
sheet piles for cofferdams.
    The goal posts would consist of 1.07 m (42 in) steel pipe piles 
that would be installed using an impact hammer for up to 130 minutes 
daily (a maximum of 2 installed per day). The duration of each strike 
of the impact hammer would be between 0.5-2 seconds in duration and 
necessitate approximately 260 strikes per pile. Up to 12 goal posts are 
required at each of the 9 casing pipe locations; hence 108 goal posts 
would be installed. Given there are 12 goal posts per each of the nine 
Direct Pipe locations, a total of 108 piles would be installed. Given 
up to 2 piles would be installed per day, there could be 520 strikes 
per day. To install all goal posts, Dominion Energy would conduct pile 
driving for 54 days.
    Once installed, the goal posts can be removed using equipment not 
expected to generate any underwater acoustic noise as the majority of 
the force applied would be to overcome the skin friction of the 
material that is embedded in the substrate. This is expected to consist 
of pulling/tugging of the piles using mechanical or hydraulic equipment 
and take a similar amount of time of installation (i.e., a total of 54 
days for removal, although no take is expected). Based on Dominion 
Energy's schedule, which includes both installation and removal of the 
goal posts, these activities are expected to occur in 2024, between May 
1st-October 31st, and necessitate approximately 6 months for complete 
installation and removal. Given no take is expected from the removal of 
goal posts, only the 54 days for installation of 108 total pipe piles 
has been carried forward into the Estimated Take of Marine Mammals 
section.
    Dominion Energy also anticipates that up to nine temporary 
cofferdams, which would only be installed and removed via vibratory 
pile driving, may be necessary during cable landfall construction 
activities. These would be located at the Nearshore Trenchless 
Installation Punch-Out location, where the export cables would 
transition (via underground drilling) to the onshore cable landing 
location, to facilitate the preferred approach of lowering of the 
Direct Pipe burial underground (approximately 2 m (6.6. ft) below the 
seabed) to reduce the need for additional cable protections and to 
minimize the release of sediments and drilling fluids into the water. 
Each temporary cofferdam would consist of 30 to 40 steel sheet piles 
measuring 0.51 m (20 in) in diameter arranged in a predetermined 
configuration (270 to 360 steel sheet piles total for all nine 
cofferdams). Vibratory pile drivers would be used to both install and 
remove the steel sheet piles. Each sheet pile would necessitate 
approximately 2 to 3 minutes of active drive time for installation, at 
a maximum installation rate of 20 sheet piles per day (up to 40-60 
minutes daily). To allow for flexibility in the plan, Dominion Energy 
has assumed installation will take approximately 3 days (180 minutes 
total) per cofferdam. Removal of these sheet piles would also occur by 
a vibratory driver and is estimated to take approximately the same 
amount of time to remove as it was to install for a total of 3 days per 
cofferdam. A single cofferdam would take a total of 6 days to install 
and remove. In total, pile driving (installation and removal) 
associated with all cofferdams would occur over 54 non-consecutive 
days.
    Collectively, Dominion Energy estimates that the installation and 
removal of all necessary components for cable landfall activities that 
have the potential to result in take of marine mammals (i.e., pile 
driving of goal posts and cofferdams) would take 108 days. However, 
within this 45 week period, activities not expected to harass marine 
mammals would also be occurring (e.g., area preparation, material 
transportation, equipment staging, etc.) as the activities necessary 
for the installation and removal of all relevant goal posts and 
cofferdams are not consecutive. Therefore, Dominion Energy has 
estimated that activities potentially resulting in the take of marine 
mammals would only be occurring for approximately 6 months between May 
1st through October 31st, 2024, which is what is described here. 
Although temporary cofferdam installation and removal is anticipated to 
occur from May 1st through October 31st of 2024 and take approximately 
6 months, per Dominion Energy's construction schedule, both 
installation and removal will not occur within a consecutive 6 days 
(the total number of days for installation and removal to occur) but 
may instead occur at different points during the 6 month estimated 
duration.
High-Resolution Geophysical Surveys
    HRG surveys would be conducted to identify any seabed debris and to 
support micro-siting of the WTG and OSS foundations and all cable 
routes. After construction is complete, HRG surveys would be conducted 
to ensure that all underwater project components have been properly 
installed. These surveys may utilize acoustic equipment such as 
multibeam echosounders, side scan sonars, shallow penetration sub-
bottom profilers (SBPs) (e.g., Compressed High-Intensity Radiated 
Pulses (CHIRPs) non-parametric SBP), medium penetration sub-bottom 
profilers (e.g., sparkers and boomers), and ultra-short baseline 
positioning equipment, some of which are expected to result in the take 
of marine mammals. Surveys would occur annually, with durations 
dependent on the activities occurring in that year (i.e., construction 
years versus operational years). Of the HRG equipment types proposed 
for use, the following sources have the potential to result in take of 
marine mammals:
     Shallow penetration sub-bottom profilers (SBPs) to map the 
near-surface stratigraphy (top 0 to 5 m (0 to 16 ft) of sediment below 
seabed). A CHIRP system emits sonar pulses that increase in frequency 
over time. The pulse length frequency range can be adjusted to meet

[[Page 28666]]

project variables. These are typically mounted on the hull of the 
vessel or from a side pole.
     Medium penetration SBPs (boomers) to map deeper subsurface 
stratigraphy as needed. A boomer is a broad-band sound source operating 
in the 3.5 Hz to 10 kHz frequency range. This system is typically 
mounted on a sled and towed behind the vessel.
     Medium penetration SBPs (sparkers) to map deeper 
subsurface stratigraphy as needed. A sparker creates acoustic pulses 
from 50 Hz to 4 kHz omni-directionally from the source that can 
penetrate several hundred meters into the seafloor. These are typically 
towed behind the vessel with adjacent hydrophone arrays to receive the 
return signals.
    Table 4 identifies all the representative survey equipment that may 
be used during the CVOW-C proposed project.

                      Table 4--Acoustic Sources Planned for Use During the CVOW-C Proposed Project and Their Operational Parameters
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                            Operating
         Equipment classification            Representative equipment      frequencies      Lp      Lp,pk         Primary beam width      Pulse duration
                                                                              (kHz)                                   (degrees)            (millisecond)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Subsea Positioning/ultra-short baseline    Sonardyne Ranger 2 USBL.....           35-55      188       191   90.........................               1
 (USBL).                                   EvoLogics S2CR..............           48-78      178       186   Horizontally                        500-600
                                                                                                              Omnidirectional.
                                           ixBlue Gaps.................           20-30      191       194   200........................            9-11
Multibeam Echosounder....................  R2Sonics 2026...............         170-450      191       221   0.45 x 0.45-1 x 1..........     0.015-1.115
Synthetic Aperture Sonar (SAS), combined   Kraken Aquapix..............             337      210       213   >135 vertical, 1 horizontal            1-10
 bathymetry/sidescan \a\.
Side Scan Sonar \a\......................  EdgeTech 4200 dual frequency     300 and 600  \b\ 206   \b\ 212   140........................            5-10
Parametric SBP...........................  Innomar SES-2000 Medium 100.            2-22      241       247   2..........................          0.07-1
NonParametric SBP........................  EdgeTech 216 CHIRP..........            2-16      193       196   15-25......................            5-40
                                           EdgeTech 512 CHIRP..........          0.5-12  \c\ 177   \c\ 191   16-41......................              20
Medium Penetration Seismic...............  Geo Marine Dual 400 Sparker           0.25-4  \d\ 200   \d\ 210   Omnidirectional............         0.5-0.8
                                            800J.
                                           Applied Acoustics S-Boom             0.5-3.5  \e\ 203   \e\ 213   \f\ 60.....................              10
                                            (Triple Plate Boomer 1000J).
Magnetometer (Towed).....................  Geometrics G882.............             200      192       190   7..........................            1.13
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: dB re 1 [micro]Pa m--decibels referenced to 1 MicroPascal at 1 meter; kHz--kilohertz.
\a\ The operating frequencies of these sources are above all relevant marine mammal hearing thresholds (>180 kHz) and are not expected to cause take by
  harassment of marine mammals.
\b\ The source level is based on data from Crocker and Franantonio (2016) using the EdgeTech 4200 at 100 percent power and 100 kHz as a proxy.
\c\ The source level is based on data from Crocker and Franantonio (2016) using the EdgeTech 512i at 100 percent power as a proxy.
\d\ The source level is based information provided by the source manufacturer in the supplemental attachment to the ITA application called ``Noise Level
  Stacked 400--tuned''.
\e\ The source level is based on data from Crocker and Franantonio (2016) using the Applied Acoustic S-Boom with CSP-N Energy Source set at 1,000 joules
  as a proxy.
\f\ The beam width is based on data from Crocker and Franantonio (2016) using the Applied Acoustics S-Boom as a proxy.

    As shown in Table 4 above, multibeam echosounders and side scan 
sonars used by Dominion Energy operate at frequencies above 180 kHz, 
which is outside of any marine mammal hearing range. Hence, take from 
these sources is not anticipated. In addition, due to the 
characteristics of non-impulsive sources (i.e., Ultra-Short BaseLine 
(USBL), Innomar, and other parametric sub-bottom profilers), take is 
not anticipated due to operating characteristics like very narrow beam 
width which limit acoustic propagation. Finally, Dominion Energy may 
also use magnetometers; however, this equipment does not have an 
acoustic output, hence no take is anticipated. No harassment can be 
reasonably expected from the operation of any of these sources; 
therefore, they are not considered further in this proposed action. The 
sources that have the potential to result in harassment to marine 
mammals include CHIRPs, boomers, and sparkers.
    HRG surveys would utilize between two or three vessels working 
concurrently in different sections of the Lease Area and Export Cable 
Routes. Both vessels would be operating several kilometers apart at any 
one time. On average, 58 km (36 mi) would be surveyed each survey day, 
per vessel, at a speed of approximately 2.4 km/hour (1.3 kts) on a 24-
hour basis although some vessels may only operate during daylight hours 
(survey vessels operating for 12-hours). During the five-years the 
proposed rule would be effective an estimated area of 64,264 km\2\ 
(24,812.5 mi\2\; 15,879,980.2 acres) will be surveyed across the CVOW-C 
project area.
    HRG site characterization surveys would occur annually and 
throughout the five years of the proposed authorization with duration 
dependent on the activities occurring in that year (i.e., construction 
versus non-construction year). However, HRG survey activities would not 
commence earlier than February 5, 2024 (i.e., the effective date of the 
proposed rule). The HRG survey schedule assumes 24-hour operations and 
does account for periods of potential downtime due to inclement weather 
or technical malfunctions. HRG surveys are anticipated to operate at 
any time of year for a maximum of 1,108 active sound source days (i.e., 
days in which an acoustic source would be used) over the five-year 
project. Up to 65 days are anticipated pre-construction, 307 are 
anticipated to occur during the primary construction years (2025 and 
2026), and 736 would occur the post-construction years (368 survey days 
annually). While the effective period of the proposed rulemaking would 
continue through a few months in 2029, no activities are planned to 
occur during this year so none are described here. An approximated 
schedule for Dominion Energy's HRG survey effort is shown in Table 5. 
As Dominion Energy is not sure of the exact geographic locations of the 
survey effort, these values cannot cleanly be broken up between the 
Lease Area and the Export Cable Routes. However, the values presented 
in Table 5 provide a comprehensive accounting of the total survey 
effort anticipated to occur, annually, by Dominion Energy.

[[Page 28667]]



      Table 5--Proposed HRG Survey Schedule for the CVOW-C Project
------------------------------------------------------------------------
                                                             Duration
             Survey segment                    Year         (days) \a\
------------------------------------------------------------------------
Pre-Lay Surveys.........................            2024              65
As-Built Surveys and Pre-Lay Surveys....            2025             249
As-Built Surveys........................            2026              58
Post-Construction Surveys...............            2027             368
Post-Construction Surveys...............            2028             368
------------------------------------------------------------------------
\a\ As multiple vessels (i.e., two survey vessels) may be operating
  concurrently across the project area, each day that a survey vessel is
  operating counts as a single survey day. For example, if two vessels
  are operating in one of the Export Cable Routes and one is operating
  in the Lease Area, but both are operating concurrently, this counts as
  two survey days.

Cable Laying and Installation
    Cable burial operations would occur both in the Lease Area and 
export cable routes from the least area to shore. The inter-array 
cables would connect the 176 WTGs to any one of the three OSSs. Cables 
within the Export Cable Routes would carry power from the OSSs to shore 
at the landfall location near the firing range at the State Military 
Reservation in Virginia Beach, Virginia. The offshore export and inter-
array cables would be buried in the seabed at a target depth of up to 
0.8 m (2.6 ft) to 3 m (9.8 ft), although the exact depth will depend on 
the substrate in the area.
    Cable laying, cable installation, and cable burial activities 
planned to occur during the construction of the CVOW-C project may 
include the following: jet plowing, jet trenching, chain cutting, 
hydro-plowing (simultaneous lay and burial), mechanical plowing 
(simultaneous lay and burial), pre-trenching (both simultaneous and 
separate lay and burial), mechanical trenching (simultaneous lay and 
burial), and/or other available technologies. As the noise levels 
generated from cable laying and installation work are low, the 
potential for take of marine mammals to result is discountable. 
Dominion Energy is not requesting and NMFS is not proposing to 
authorize take associated with cable laying activities. Therefore, 
cable laying activities are not analyzed further in this document.
Site/Seafloor Preparation
    Prior to installation activities, Dominion Energy would conduct 
debris clearance, pre-lay grapnel runs, Unexploded Ordnance/Munitions 
and Explosives of Concern (UXO/MEC) relocation, and pre-lay surveys. 
While Dominion Energy does not expect any sandwave clearance or boulder 
removal activities to occur, planned vessel use described below in 
Table 6 indicates that these activities may occur. Because of this, we 
include additional information on what these activities may entail and 
how they would affect marine mammals.
    Typically for offshore construction projects, some dredging may be 
required prior to cable laying due to the presence of sandwaves. 
Sandwave clearance is typically undertaken where cable exposure is 
predicted over the lifetime of a project due to seabed mobility. This 
facilitates cable burial below the reference seabed. Alternatively, 
sandwave clearance may be undertaken where slopes become greater than 
approximately 10 degrees (17.6 percent), which could cause instability 
to the burial tool. Dominion Energy does not anticipate any sandwave 
clearance (Dominion Energy, 2023). However, while unanticipated, if it 
becomes necessary to remove sandwaves, Dominion Energy will clear the 
area using subsea excavation methods. The work could be undertaken by 
traditional dredging methods such as a trailing suction hopper. 
Controlled flow excavation may be used to induce water currents to 
force the seabed into suspicion, where it would otherwise be directed 
to eventually settle (Dominion Energy, 2023). In some cases, pre-
sweeping of the sandwaves may be necessary to provide a sufficient 
excavated platform at the base of the sandwave for tool installation. 
Surveys using multi-beams and other equipment may be necessary to 
inform on the seabed conditions before and after sandwave clearance and 
cable lay activities (Dominion Energy, 2023).
    For monopile and jacket foundation installation, seafloor 
preparation could include required boulder clearance and removal of any 
obstructions within the Seafloor Preparation Area at each foundation 
location. Scour protection installation will occur prior to and/or 
after installation and will involve a rock dumping vessel placing scour 
at each foundation location.
    For export cable installation, seafloor preparation typically 
includes required sandwave leveling, boulder clearance, and removal of 
any out of service cables. Boulder clearance trials are normally 
performed prior to wide-scale seafloor preparation activities to 
evaluate efficacy of boulder clearing techniques. Additionally, pre-lay 
grapnel runs may be undertaken to remove any seafloor debris along the 
Export Cable Routes. A specialized vessel will tow a grapnel rig along 
the centerline of each cable to recover any debris to the deck for 
appropriate licensed disposal ashore, where practicable. Concrete 
mattress separation layers may also be installed at cable routes prior 
to cable installation for both in-service assets as well as out-of-
service assets that cannot be safely removed and pose a risk to the 
CVOW-C Export Cable Routes.
    Boulder clearance may also be required in targeted locations to 
clear boulders along the Export Cable Routes, inter-array cable routes, 
and/or foundations prior to installation. Boulder removal can be 
performed using a combination of methods to optimize clearance of 
boulder debris of varying size and frequency. Removal is based on pre-
surveys to identify location, size, and density of boulders. Surveys 
previously performed by Dominion Energy have indicated that no boulders 
over 0.5 m, or any other subsea obstructions, have been identified in 
the project area (Dominion Energy, 2023). If boulders are encountered 
during installation activities, Dominion Energy would move them from 
the Export Cable Routes, using either subsea grabs, or ploughs, and 
then relocate them to areas as close as possible to the original 
location of the undersea object (Dominion Energy, 2023). Boulder 
removal, if necessary to occur based on information obtained during 
pre-construction surveys, would be performed prior to the installation 
of the Export Cable Routes and would be completed by a support vessel. 
A boulder grab or a boulder plow may be used to complete boulder 
removal prior to installation. A boulder grab involves a grab most 
likely deployed from a dynamic positioning offshore support vessel 
being lowered to the seabed, over the targeted boulder. Once 
``grabbed'', the boulder is relocated away from the cable route and/or 
foundation location.

[[Page 28668]]

Boulder clearance using a boulder plow is completed by a high-bollard 
pull vessel, with a towed plow generally forming an extended V-shaped 
configuration, splaying from the rear of the main chassis. The V-shaped 
configuration displaces any boulders to the extremities of the plow, 
thus clearing the corridor. A tracked plow with a front blade similar 
to a bulldozer may also be used to push boulders away from the 
corridor. The size of boulders that can be relocated is dependent on a 
number of factors including the boulder weight, dimensions, embedment, 
density and ground conditions. Typically, boulders with dimensions less 
than 2.5 m (8 ft) can be relocated with standard tools and equipment.
    Effects from seafloor preparation on marine mammals are expected to 
be short-term, low intensity, and unlikely to qualify as a take. 
Dredging, sandwave leveling, and boulder clearance is expected to be 
extremely localized at any given time, and NMFS expects that any marine 
mammals would not be exposed at levels or durations likely to disrupt 
behavioral patterns (i.e., migrating, foraging, calving, etc.). 
Therefore, the potential for take of marine mammals to result from 
these activities is so low as to be discountable. Dominion Energy did 
not request and NMFS is not proposing to authorize any takes associated 
with seabed preparation activities; therefore, they are not analyzed 
further in this document.
Vessel Operation
    Dominion Energy would utilize a variety of vessels to construct the 
CVOW-C project. Vessels may be used for direct installation or 
construction activities, surveys, protected species resource 
monitoring, and for crew and/or supply transfers. All route plans for 
all vessels would be designed to meet the industry guidelines and best 
practices in accordance with the International Chamber of Shipping 
guidance. All vessels would utilize Automatic Identification Systems 
(AIS) for all aspects of the project, as required by the United States 
Coast Guard. AIS would be required to monitor the number of vessels and 
traffic patterns for analysis and compliance with vessel speed 
requirements. All vessels will operate in accordance with applicable 
rules and regulations for maritime operation within U.S. Federal and 
state waters.
    The largest vessels are expected to be used during the WTG 
installation phase with floating/jack-up crane barges, cable-laying 
vessels, supply/crew vessels, and/or associated tugs and barges 
transporting construction equipment and materials. Large work vessels 
(e.g., jack-up installation vessels and DP cable-laying vessels) for 
WTG and OSS foundation installation will generally transit to the work 
location and remain in the area until installation is complete. These 
large vessels will move slowly over a short distance between work 
locations. In contrast, other vessels will travel between several ports 
and the Lease Area over the course of the construction period following 
mandatory vessel speed restrictions (see Proposed Mitigation section). 
These vessels will range in size from smaller crew transport boats to 
tug and barge vessels. However, construction crews responsible for 
assembling the WTGs will hotel onboard installation vessels at sea, 
thus limiting the number of crew vessel transits expected during the 
installation of the Lease Area.
    While marine mammals may respond to the presence of a vessel, given 
the predictable movement and ubiquitous presence of vessels in the 
marine environment, and especially the variable sizes, which consist of 
smaller support vessels that are predominate during offshore wind 
development, exposure to transiting vessels would not generally be 
expected to result in the disruption of marine mammal behavioral 
patterns such that a take would occur. As part of various vessel-based 
construction activities, including cable laying and construction 
material delivery, dynamic positioning thrusters may be utilized to 
hold vessels in position or move slowly. Sound produced through use of 
dynamic positioning thrusters is similar to that produced by transiting 
vessels, and dynamic positioning thrusters are typically operated 
either in a similarly predictable manner or used for short durations 
around stationary activities. Construction-related vessel activity, 
including the use of dynamic positioning thrusters, is not expected to 
result in take of marine mammals. Dominion Energy did not request and 
NMFS does not propose to authorize any take associated with vessel 
activity.
    Dominion Energy has executed a lease agreement for a portion of the 
existing Portsmouth Marine Terminal facility in the city of Portsmouth, 
Virginia, to serve as a Construction Port (Sections 1-3, Dominion 
Energy, 2023). The Construction Port would be used to stage and store 
the monopiles and relevant transition pieces and to stage and store and 
pre-assemble wind turbine generation components. Dominion Energy is 
also currently evaluating several alternatives to lease portions of 
existing port facilities in the Hampton Roads, Virginia area for an 
operation and maintenance facility for the CVOW-C proposed project. The 
preferred location is Lambert's Point, located on a brownfield site in 
Norfolk, Virginia, although existing facilities at the Virginia Port 
Authority's Portsmouth Marine Terminal or Newport News Marine Terminal 
may also be viable options. These ports will continue to assist 
Dominion Energy to support offshore construction, assembly and 
fabrication, crew transfers, and logistics.
    Vessel types and usage estimated to occur during the entire five-
year effective period of the proposed rule, if issued, is shown in 
Table 6. NMFS references the reader to Dominion Energy's COP for 
additional information on vessels planned for use during the CVOW-C 
proposed project (Dominion Energy, 2023).

                                                            Table 6--Proposed Project Vessel Use During the 5-Year CVOW-C Project \1\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                 Days on
                                                                                                                 project,
            Vessel role                  Vessel class       Number of     Breadth    Length (ft)   Draft (ft)   including   Most likely operating  Frequency of transit    Transit destination
                                                             vessels        (ft)                                  spare             period
                                                                                                                positions
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Scour Protection Installation.....  Fall Pipe Vessel.....            1          106          507           25          657  10/2023 to 12/2024     Weekly..............  Canada/USA.
                                                                                                                             and 02/2025 to 10/
                                                                                                                             2025.

[[Page 28669]]

 
Transport Monopile/Transition       U.S. Barge...........            2          105          400           20          823  04/2024 to 12/2025...  (188+17)/2 = 103      Portsmouth, VA.
 Pieces from U.S. Port to                                                                                                                           cycles in total for
 Installation Site.                                                                                                                                 all barges.
Tugs for Monopile/Transition Piece  U.S. Ocean-going Tug.            3           41          132           18          823  04/2024 to 12/2025...  103 + 52 = 155        Portsmouth, VA.
 Transport Barges.                                                                                                                                  cycles in total.
Monopile/Transition Piece/Offshore  Heavy Lift Vessel                1          161          711           36          804  04/2024 to 12/2025...  Monthly.............  Europe/Hampton Roads,
 Substation Installation.            (HLV).                                                                                                                               VA.
Noise Monitoring..................  Crew Transfer Vessel             2           34           84            7          512  05/2024 to 10/2024     Daily...............  Portsmouth, VA.
                                     (CTV).                                                                                  and 05/2025 to 10/
                                                                                                                             2025.
Noise Mitigation..................  Platform Support                 1          100          454           29          512  05/2024 to 10/2024     2 cycles in total +   Portsmouth, VA.
                                     Vessel.                                                                                 and 05/2025 to 10/     X due to bad
                                                                                                                             2025.                  weather.
Crew Transfer.....................  CTV..................            1           23           65            6          822  04/2024 to 12/2025...  Every 2\nd\ day.....  Portsmouth, VA.
Jacket Installation...............  DP HLV...............            1          161          710           36  ...........  .....................  Monthly.............  Europe/Hampton Roads,
                                                                                                                                                                          VA.
Noise Monitoring for Jacket         Crew Transfer Vessel             2           34           84            7  ...........  .....................  Daily...............  Portsmouth, VA.
 Installation.                       (CTV).
Noise Mitigation for Jacket         Platform Support                 1          100          454           29  ...........  .....................  Daily...............  Portsmouth, VA.
 Installation.                       Vessel.
Transport Jackets/TopSides From EU  HLV..................            1          138          568           35          186  11/2024 to 04/2025...  3 cycles in total...  Europe.
 Port to Installation Site.
Assist Tugboat For Topside          U.S. Ocean-going Tug.            1           35          112           19  ...........  .....................  Daily...............  Hampton Roads, VA.
 Installation.
Offshore Cable Commissioning        DP2 JUV..............            2          230          132           20          288  11/2024 to 07/2025...  N/A.................  N/A.
 (Contingency Vessel).
Nearshore Trenchless Installation.  Drill Rig Spread.....            2           40            9          N/A          262  09/2023 to 02/2024...  N/A (staged at the    Hampton Roads, VA.
                                                                                                                                                    direct pipe punch-
                                                                                                                                                    out locations).
Nearshore Marine Assistance.......  U.S. Multi Purpose               2           40           92           14          262  .....................  Weekly..............  Portsmouth, VA.
                                     Support Vessel
                                     (Multicat).
Nearshore Marine Assistance.......  U.S. Tug (Small).....            1           35          112           19          262  .....................  Weekly..............  Portsmouth, VA.
Landfall..........................  Landfall Beach Spread            1          N/A          N/A          N/A          523  01/2023 to 04/2024     Weekly..............  Hampton Roads, VA.
                                                                                                                             and.
Shore Pull-in.....................  U.S. Pull-in Support             1          105          400           20          523  07/2024 to 09/2025...  Weekly..............  Portsmouth, VA.
                                     Barge.
Shore Pull-in.....................  U.S. Workboat (Tug)..            4           41          132           18          523  .....................  Weekly..............  Portsmouth, VA.
Cable Lift Jack-Up Installation     JUV..................            1          105          144           13  ...........  .....................  ....................  .......................
 Vessel (Contingency Vessel).
Pre-lay Grapnel Run...............  Multipurpose Support             1           59          266           19           77  .....................  Weekly..............  Portsmouth, VA.
                                     Vessel.
Pre-installation Survey...........  Survey Vessel........            1          234          187           10          180  .....................  Weekly..............  Portsmouth, VA.

[[Page 28670]]

 
Cable Laying and Burial...........  Shallow-draft Cable              1          110          401           18          523  .....................  Monthly.............  Europe/Hampton Roads,
                                     Lay Vessel.                                                                                                                          VA.
Anchor Handling...................  Multi Purpose Support            2           40           92           14          523  .....................  Daily...............  Hampton Roads, VA.
                                     Vessel (Multicat).
Transport Cable...................  Multi Purpose Support            3           79          289           15          131  .....................  Single Trip.........  Europe/Hampton Roads,
                                     Vessel.                                                                                                                              VA.
Cable Burial......................  Hydroplow (Jetting)..            1           20           53           14          523  .....................  N/A.................  Europe/Hampton Roads,
                                                                                                                                                                          VA.
Crew Transfer.....................  CTV..................            1           34           87           10          523  .....................  Every 2nd Day.......  Portsmouth, VA.
As-built Survey...................  Survey Vessel........            1          234           87           10           46  .....................  Weekly..............  Portsmouth, VA.
Pre-lay Survey (Offshore Export     Survey Vessel........           34           87           10           10          180  1/2023 to 04/2024 and  Weekly..............  Portsmouth, VA.
 Cable).                                                                                                                     08/2024 to 09/2025
                                                                                                                             and 11/2025 to 02/
                                                                                                                             2026.
Cable Laying and Burial (Offshore   Deep-draft Cable Lay             1          106          528           22          535  .....................  Monthly.............  Hampton Roads, VA.
 Export Cable).                      Vessel.
Cable Laying and Burial (Offshore   Deep-draft Cable Lay             1           39          110            9          470  .....................  Monthly.............  Europe/Hampton Roads,
 Export Cable).                      Vessel.                                                                                                                              VA.
Cable burial (Offshore Export       Trenching Support or             1          105          529           25          604  .....................  Monthly.............  Europe/Hampton Roads,
 Cable).                             Cable Laying Vessel.                                                                                                                 VA-.
Cable burial (Offshore Export       Trenching Support or             1          112          561           28          605  .....................  Monthly.............  Europe/Hampton Roads,
 Cable).                             Cable Laying Vessel.                                                                                                                 VA-.
Cable burial (Offshore Export       Burial Tool (Post-lay            2           25           46           19        1,209  .....................  Monthly.............  Europe/Hampton Roads,
 Cable).                             Jetting).                                                                                                                            VA-.
Offshore Jointing Vessel (Offshore  .....................            1           23          565            6  ...........  .....................  Monthly.............  Europe/Hampton Roads,
 Export Cable).                                                                                                                                                           VA.
Pre-lay Grapnel Run (Inter Array    Multipurpose Support             1           26           92            9          109  01/2023 to 04/2024     Weekly..............  Portsmouth, VA.
 Cable).                             Vessel.                                                                                 and 11/2024 to 05/
                                                                                                                             2026.
Pre-lay Survey (Inter-Array Cable)  Survey Vessel........            1           23           85            5           52  .....................  Weekly..............  Portsmouth, VA.
Cable Laying and burial (Inter-     Deep-draft Cable Lay             1          106          528           25          558  .....................  Every 60 days.......  Europe/Hampton Roads,
 Array Cable).                       Vessel.                                                                                                                              VA.
Multipurpose Service Vessel (Inter- W2W..................            2           76          292           18          303  .....................  Monthly.............  Hampton Roads, VA.
 Array Cable).
Crew Transfer (Inter-Array Cable).  CTV..................            2           23           65            6          558  .....................  Every 2nd Day.......  Portsmouth, VA.
Cable Burial (Inter-Array Cable)..  Trenching Support                1          105          529           37          559  .....................  Every 60 days.......  Hampton Roads, VA.
                                     Vessel or Cable
                                     Laying Vessel.
Cable Burial (Inter-Array Cable)..  Burial tool (Post-lay            1           25           46           19          558  .....................  Every 60 days.......  Hampton Roads, VA.
                                     Jetting).
As-built Survey (Inter-Array        Deep draft Cable Lay             1          106          528           25           38  .....................  Weekly..............  Portsmouth, VA.
 Cable).                             Vessel.
WTG Installation..................  JUV..................            1          184          472           23          923  08/2025 to 02/2027...  Vessel 1: Every 10-   Vessel 1: Portsmouth,
                                                                                                                                                    14 days Vessel 2: N/  VA Vessel 2: N/A.
                                                                                                                                                    A.

[[Page 28671]]

 
Transport WTGs from U.S. port to    U.S. Barge...........            2          100          400           20          792  .....................  Approximately every   Portsmouth, VA.
 installation site.                                                                                                                                 3 days.
Transport WTGs from U.S. Port to    U.S. Ocean-going Tug.            2           41          132           18          792  .....................  Approximately every   Portsmouth, VA.
 Installation Site.                                                                                                                                 3 days.
Assist Tugboat....................  U.S. Ocean-going Tug.            1           35          112           19  ...........  .....................  Approximately every   Hampton Roads, VA.
                                                                                                                                                    3 days.
Commissioning Spread..............  Multi-role subsea                1           52          354           18          792  08/2025 to 04/2027...  Bi-weekly...........  Portsmouth, VA.
                                     Support Vessel with
                                     W2W.
Site Security.....................  Safety vessel,                   1       Varies       Varies       Varies       1.8684  09/2023 to 08/2027...  Bi-weekly...........  Portsmouth, VA.
                                     Nearshore Trenchless
                                     Installation.
Removing Sandwaves (Contingency     Trailer Suction                  1           92          480           30        117.6  2023.................  Daily...............  Portsmouth, VA.
 Vessel).                            Hopper Dredger.
Boulder Pickering (Contingency      Anchor Handling Tug +            2           46          146           21        117.6  2023.................  Weekly..............  Portsmouth, VA.
 Vessel).                            Crane Barge.
Boulder Ploughing (Contingency      Anchor Handling Tug +            1           36          190           11        157.2  2023.................  Weekly..............  Portsmouth, VA.
 Vessel).                            Towed Plow.
Crossing Protection (Concrete       Fall Pipe Vessel or              1           46          146           21          126  2024 to 2026.........  Between 2 and 27      Portsmouth, VA.
 Mattresses).                        Deep Draft Cable Lay                                                                                           cycles.
                                     Vessel.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: N/A means not applicable and--means the information was not provided by Dominion Energy.
\1\ While most of these vessels are planned for construction, not all would be used. However, NMFS has opted to include all possible vessels with all available information to provide the best
  possible understanding of what vessels may be involved in the CVOW-C proposed project.

Helicopter Usage
    Dominion Energy may supplement vessel-based transport with 
helicopter usage to transfer crew to and from both the shore and the 
Lease Area (crew transfer vessels described in Table 6 above does not 
consider helicopter use and thus, is a conservative estimate). 
Helicopter usage would align with the best practices from the Federal 
Aviation Administration and other relevant stakeholders when 
determining routes and altitudes for travel. Helicopter use is expected 
primarily from 2024-2026 at a rate of up to four roundtrip flights per 
week, equating to 208 roundtrips annually and up to 624 roundtrips 
total. Project-related aircraft would only occur at low altitudes over 
water during takeoff and landing at an offshore location where one or 
more vessels are located. Helicopters produce sounds that can be 
audible to marine mammals; however, most sound energy from aircraft 
reflects off the air-water interface as only sound radiated downward 
within a 26-degree cone penetrates below the surface water (Urick, 
1972). Due to the intermittent nature and the small area potentially 
ensonified by this sound source for a very limited duration, Dominion 
Energy did not request, and NMFS is not proposing to authorize take of 
marine mammals incidental to helicopter flights; therefore, this 
activity will not be discussed further in this proposed action.
Fisheries Monitoring Surveys
    Dominion Energy plans to undertake fisheries monitoring surveys, in 
partnership with the Virginia Institute of Marine Sciences (VIMS), 
Atlantic surf clam (Spisula solidissima) fishers, black sea bass 
(Centropristis striata) fishers, whelk (Buccinidae spp.) fishers, 
Rutgers University, and the Virginia Marine Resource Commission (VMRC), 
as required by BOEM to support the regulatory filings for renewable 
energy projects proposed in the Atlantic Lease Areas (30 CFR 
585.627(a)(3)). Fisheries monitoring surveys have been designed in 
accordance with recommendations set forth by the Responsible Offshore 
Science Alliance (ROSA) Offshore Wind Project Monitoring Framework and 
Guidelines (https://www.rosascience.org/offshore-wind-and-fisheries-resources/; ROSA, 2021), which is based extensively on existing BOEM 
guidance for providing information on fisheries during work related to 
offshore wind projects (https://www.boem.gov/sites/default/files/renewable-energy-program/Regulatory-Information/BOEM-Fishery-Guidelines.pdf; BOEM, 2019). Dominion Energy would sample black sea 
bass and whelks using pots with weighted groundlines and Atlantic surf 
clams using a novel dredge tow (designed by Rutgers University and 
other industry experts). The pot/trap surveys will have a two-day soak 
time. Dominion Energy will be using on-demand fishing systems aimed at 
reducing the entanglement risk to protected species. These systems 
include, but are not limited to, spooled systems, buoy and stowed 
systems, lift bag systems, and grappling (more information on these 
systems can be found at https://www.fisheries.noaa.gov/new-england-

[[Page 28672]]

mid-atlantic/marine-mammal-protection/developing-viable-demand-gear-
systems#:~:text=Line%20wrapped%20around%20a%20buoyant%20spool%20is%20tet
hered,retrieve%20it%2C%20and%20the%20gear%20on%20the%20string). The 
survey tows completed by this dredge will be shorter than typical 
commercial tows. Dredge tows do not inherently have the potential to 
result in take of marine mammals. Pot-based surveys may, absent 
mitigation, result in the take of marine mammals. However, Dominion 
Energy would implement mitigation and monitoring measures to avoid 
taking marine mammals, including, but not limited to: monitoring for 
marine mammals before and during dredging and gear deployment 
activities, not deploying or pulling gear in certain circumstances, 
maintaining marine mammal watches at least 15 minute before to both the 
deployment and retrieval of the gear, and moving to a new sampling 
location if a marine mammal appears at risk of interactions with the 
gear. A full description of the mitigation measures can be found in the 
Proposed Mitigation section. Dominion Energy had also proposed to 
conduct trawl surveys; however, they subsequently removed trawling from 
their plans. Hence, trawl surveys would not occur.
    With the implementation of these measures, Dominion Energy does not 
anticipate, and NMFS is not proposing, to authorize take of marine 
mammals incidental to fishery surveys. Given no take is anticipated 
from these surveys, impacts from fishery surveys will not be discussed 
further in this document aside from listing the required mitigation 
measures (see Proposed Mitigation section).

Description of Marine Mammals in the Area of Specified Activities

    Thirty-nine marine mammal species under NMFS' jurisdiction have 
geographic ranges within the western North Atlantic OCS (Hayes et al., 
2022), with six of these being protected under the Endangered Species 
Act (ESA). However, for reasons described below, Dominion Energy has 
requested and NMFS proposes to authorize take of only 21 species 
(comprising 22 stocks) of marine mammals. Sections 3 and 4 of Dominion 
Energy's application summarize available information regarding status 
and trends, distribution and habitat preferences, and behavior and life 
history of the potentially affected species (Dominion Energy, 2023). 
NMFS fully considered all of this information, and we refer the reader 
to these descriptions in the application, incorporated here by 
reference, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS's website (https://www.fisheries.noaa.gov/find-species).
    Of the 39 marine mammal species and/or stocks with geographic 
ranges that include the CVOW-C project area found in the coastal and 
offshore waters of Virginia (Table 11 in Dominion Energy's ITA 
application), 17 are not expected to be present or are considered rare 
or unexpected in the project area based on sighting and distribution 
data; they are, therefore, not discussed further beyond the explanation 
provided here. Specifically, the following cetacean species are known 
to occur offshore of Virginia but are not expected to occur in the 
project area due to the location of preferred habitat outside the Lease 
Area and Export Cable Routes, based on the best available information: 
dwarf sperm whale (Kogia sima), Fraser's dolphin (Lagenodelphis hosei), 
killer whale (Orcinus orca), pygmy killer whale (Feresa attenuata), 
rough-toothed dolphin (Steno bredanensis), spinner dolphin (Stenalla 
longirostris orientalis), striped dolphin (Stenella coeruleoalba), 
white-beaked dolphin (Lagenorhynchus albirostris), Cuvier's beaked 
whale (Ziphius cavirostris), four species of Mesoplodont beaked whales 
(Mesoplodon densitostris, M. europaeus, M. mirus, and M. bidens), and 
the blue whale (Balaenoptera musculus). Two species of phocid pinnipeds 
are also uncommon in the CVOW-C project area, including: harp seals 
(Pagophilus groenlandica) and hooded seals (Cystophora cristata). In 
addition, the Florida manatees (Trichechus manatus; a sub-species of 
the West Indian manatee) has been previously documented as an 
occasional visitor to the Mid-Atlantic region during summer months 
(Morgan et al., 2002; Cummings et al., 2014). However, manatees are 
managed by the U.S. Fish and Wildlife Service (USFWS) and are not 
considered further in this document.
    None of the aforementioned species were observed during HRG surveys 
conducted by Dominion Energy in and around Virginia from 2018-2021 
based on monitoring reports received for previously issued high-
resolution site characterization IHAs (85 FR 55415, September 8, 2020; 
85 FR 81879, December 17, 2020; 86 FR 21298, April 22, 2021), for the 
construction of the CVOW Pilot Project (85 FR 30930, May 21, 2020) or 
Unexploded Ordnance/Munitions and Explosives of Concern (UXO/MEC)-
specific surveys (83 FR 39062, August 8, 2018). However, four marine 
mammal species that might otherwise be considered rare were detected 
through PAM/visually observed by marine mammal monitors during work 
under these previous IHAs. These include: false killer whales (one 
acoustically detected, four observed), pygmy sperm whales (one 
acoustically detected, one observed), Clymene dolphin (five observed), 
and melon-headed whales (one acoustically detected, five recorded). 
Although these were detected in low numbers, these observations/
detections did occur within locations near the CVOW-C project area 
where NMFS considers it reasonably likely that some individuals may be 
observed during the five-year effective period of the proposed 
rulemaking. Because of this, NMFS has proposed to authorize take of 
these species.
    Table 7 lists all species and stocks for which take is expected and 
proposed to be authorized for this action, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and Endangered Species Act (ESA) and potential biological 
removal (PBR) level, where known. PBR is defined by the MMPA as the 
maximum number of animals, not including natural mortalities, that may 
be removed from a marine mammal stock while allowing that stock to 
reach or maintain its optimum sustainable population (16 U.S.C. 
1362(20)) and can be found in NMFS's SARs. While no mortality is 
anticipated or proposed for authorization here, PBR and annual serious 
injury and mortality from anthropogenic sources are included here as 
gross indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Atlantic and Gulf of Mexico SARs. All values presented in 
Table 7 are the most recent available at

[[Page 28673]]

the time of publication and are available in NMFS' final 2021 SARs 
(Hayes et al., 2022) and draft 2022 SARs available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports.

           Table 7--Marine Mammal Species \5\ Likely to Occur Near the Project Area That May Be Taken by Dominion Energy's Proposed Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                Annual
                                                                                       ESA/ MMPA status;   Stock abundance (CV,              mortalities
             Common name                  Scientific name               Stock            strategic (Y/       Nmin, most recent       PBR      or serious
                                                                                             N)\1\         abundance survey) \2\             injuries (M/
                                                                                                                                               SI) \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           Order Artiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
    North Atlantic right whale......  Eubalaena glacialis....  Western Atlantic......  E, D, Y            338 (0; 332; 2020) \5\        0.7         8.1
Family Balaenopteridae (rorquals):
    Fin whale.......................  Balaenoptera physalus..  Western North Atlantic  E, D, Y            6,802 (0.24; 5,573;            11         1.8
                                                                                                           2016).
    Humpback whale..................  Megaptera novaeangliae.  Gulf of Maine.........  -, -, Y            1,396 (0; 1,380; 2016)         22       12.15
    Minke whale.....................  Balaenoptera             Canadian Eastern        -, -, N            21,968 (0.31; 17,002;         170        10.6
                                       acutorostrata.           Coastal.                                   2016).
    Sei whale.......................  Balaenoptera borealis..  Nova Scotia...........  E, D, Y            6,292 (1.02; 3,098;           6.2         0.8
                                                                                                           2016).
Family Physeteridae:
    Sperm whale.....................  Physeter macrocephalus.  North Atlantic........  E, D, Y            4,349 (0.28; 3,451;           3.9           0
                                                                                                           2016).
Family Kogiidae:
    Pygmy sperm whale \7\ \8\.......  Kogia breviceps........  Western North Atlantic  -, -, N            7,750 (0.38; 5,689;            46           0
                                                                                                           2016).
Family Delphinidae:
    Atlantic spotted dolphin........  Stenella frontalis.....  Western North Atlantic  -, -, N            39,921 (0.27; 32,032;         320           0
                                                                                                           2016).
    Atlantic white-sided dolphin....  Lagenorhynchus acutus..  Western North Atlantic  -, -, N            93,233 (0.71; 54,433;         544          27
                                                                                                           2016).
    Bottlenose dolphin..............  Tursiops truncatus.....  Western North           -, -, N            62,851 (0.23; 51,914;         519          28
                                                                Atlantic--Offshore.                        2016).
                                                               Southern Migratory      -, -, Y            3,751 (0.6; 185; See           23      0-18.3
                                                                Coastal.                                   SAR).
    Clymene dolphin \7\.............  Stenella clymene.......  Western North Atlantic  -, -, N            4,237 (1.03; 2,071;            21           0
                                                                                                           2016).
    Common dolphin..................  Delphinus delphis......  Western North Atlantic  -, -, N            172,897 (0.21;              1,452         390
                                                                                                           145,216; 2016).
    False killer whale \7\..........  Pseudorca crassidens...  Western North Atlantic  -, -, N            1,791 (0.56; 1,154;            12           0
                                                                                                           2016).
    Melon-headed whale \7\..........  Peponocephala electra..  Western North Atlantic  -, -, N            UNK (UNK; UNK; 2016)..        UNK           0
    Long-finned pilot whale \6\.....  Globicephala melas.....  Western North Atlantic  -, -, N            39,215 (0.3; 30,627;          306          29
                                                                                                           2016).
    Short-finned pilot whale \6\....  Globicephala             Western North Atlantic  -, -, Y            28,924 (0.24, 23,637,         236         136
                                       macrorhynchus.                                                      See SAR).
    Pantropical spotted dolphin.....  Stenella attenuata.....  Western North Atlantic  -, D, N            6,593 (0.52, 4,367,            44           0
                                                                                                           See SAR).
    Risso's dolphin.................  Grampus griseus........  Western North Atlantic  -, -, N            35,215 (0.19; 30,051;         301          34
                                                                                                           2016).
Family Phocoenidae (porpoises):
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Harbor porpoise.................  Phocoena phocoena......  Gulf of Maine/Bay of    -, -, N            95,543 (0.31; 74,034;         851          16
                                                                Fundy.                                     2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Gray seal \4\...................  Halichoerus grypus.....  Western North Atlantic  -, -, N            27,300 (0.22; 22,785;       1,389       4,453
                                                                                                           2016).
    Harbor seal.....................  Phoca vitulina.........  Western North Atlantic  -, -, N            61,336 (0.08; 57,637;       1,729         339
                                                                                                           2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
  which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS' marine mammal stock assessment reports can be found online at: www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is the coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike).
\4\ NMFS' stock abundance estimate (and associated PBR value) applies to the U.S. population only. Total stock abundance (including animals in Canada)
  is approximately 451,431. The annual M/SI value given is for the total stock.
\5\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\6\ Although both species are described here, the requested take for both short-finned and long-finned pilot whales has been summarized into a single
  group (pilot whales spp.).
\7\ While these species were not originally included in Dominion Energy's request, given recorded sightings/detections of these species during previous
  Dominion Energy IHAs in the same general area, NMFS has included these as species that may be harassed (by Level B harassment only) during the five-
  year effective period of this proposed rulemaking.
\8\ Estimate is for Kogia spp. only.


[[Page 28674]]

    As indicated above, all 21 species and 22 stocks in Table 7 
temporally and spatially co-occur with the activity to the degree that 
take is reasonably likely to occur. Four of the marine mammal species 
for which take is requested are listed as threatened or endangered 
under the ESA, including North Atlantic right, fin, sei, and sperm 
whales. In addition to what is included in Sections 3 and 4 of Dominion 
Energy's ITA application (https://www.fisheries.noaa.gov/action/incidental-take-authorization-dominion-energy-virginia-construction-coastal-virginia), the SARs (https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments), and NMFS' 
website (https://www.fisheries.noaa.gov/species-directory/marine-mammals), we provide further detail below informing the baseline for 
select species (e.g., information regarding current Unusual Mortality 
Events (UME) and known important habitat areas, such as Biologically 
Important Areas (BIAs) (Van Parijs, 2015). There are no ESA-designated 
critical habitats for any species within the CVOW-C project area.
    Under the MMPA, a UME is defined as ``a stranding that is 
unexpected; involves a significant die-off of any marine mammal 
population; and demands immediate response'' (16 U.S.C. 1421h(6)). As 
of April 13, 2023, five UMEs are considered active, with four of these 
occurring along the U.S. Atlantic coast for various marine mammal 
species; of these, the most relevant to the CVOW-C project are the 
North Atlantic right whale and the humpback whale, given the prevalence 
of these species in the project area. A more recent UME is active for 
the Northeast pinnipeds (harbor and gray seals) but has only been 
recorded in Maine, which is outside the project area. Two other UMEs, 
one for the Atlantic minke whale from 2017-2022 and one for the 
Northeast pinnipeds (harbor and gray seals) from 2018-2020, are 
considered non-active and are pending closure. More information on 
UMEs, including all active, closed, or pending, can be found on NMFS' 
website at https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events.
    Below we include information for a subset of the species that 
presently have an active or recently closed UME occurring along the 
Atlantic coast, or for which there is information available related to 
areas of biological significance. For the majority of species 
potentially present in the specific geographic region, NMFS has 
designated only a single generic stock (e.g., ``western North 
Atlantic'') for management purposes. This includes the ``Canadian east 
coast'' stock of minke whales, which includes all minke whales found in 
U.S. waters and is also a generic stock for management purposes. For 
humpback and sei whales, NMFS defines stocks on the basis of feeding 
locations, i.e., Gulf of Maine and Nova Scotia, respectively. However, 
references to humpback whales and sei whales in this document refer to 
any individuals of the species that are found in the specific 
geographic region. Any areas of known biological importance (including 
the BIAs identified in La Brecque et al., 2015) that overlap spatially 
with the project area are addressed in the species sections below.

North Atlantic Right Whale

    The North Atlantic right whale has been listed as Endangered since 
the ESA was enacted in 1973. They were recently uplisted from 
Endangered to Critically Endangered on the International Union for 
Conservation of Nature (IUCN) Red List of Threatened Species (Cooke, 
2020). The uplisting was due to a decrease in population size (Pace et 
al., 2017), an increase in vessel strikes and entanglements in fixed 
fishing gear (Knowlton et al., 2012; Daoust et al., 2017; Davis and 
Brillant, 2019; Sharp et al., 2019; Moore et al., 2021; Knowlton et 
al., 2022), and a decrease in birth rate (Pettis et al., 2021; Reed et 
al., 2022). The Western Atlantic stock is considered depleted under the 
MMPA (Hayes et al., 2022). There is a recovery plan (NOAA Fisheries, 
2005) for the North Atlantic right whale, and NMFS completed 5-year 
reviews of the species in 2012,2017, and 2022 which concluded no change 
to the listing status is warranted.
    The North Atlantic right whale population had only a 2.8 percent 
recovery rate between 1990 and 2011, and an overall abundance decline 
of 29.7 percent from 2011-2020 (Hayes et al., 2022). Since 2010, the 
North Atlantic right whale population has been in decline (Pace et al., 
2017; Pace et al., 2021), with a 40 percent decrease in calving rate 
(Kraus et al., 2016; Moore et al., 2021). North Atlantic right whale 
calving rates dropped from 2017 to 2020, with zero births recorded 
during the 2017-2018 season. The 2020-2021 calving season had the first 
substantial calving increase in five years, with 20 calves born, 
followed by 15 calves during the 2021-2022 calving season. However, 
mortalities continue to outpace births, and best estimates indicate 
fewer than 100 reproductively active females remain in the population.
    NMFS' regulations at 50 CFR 224.105 designated nearshore waters of 
the Mid-Atlantic Bight as Mid-Atlantic U.S. Seasonal Management Areas 
(SMAs) for right whales in 2008. These specific SMAs were developed to 
reduce the threat of collisions between ships and right whales around 
their migratory route and calving grounds. As mentioned previously, the 
Chesapeake Bay SMA is within the vicinity of the proposed project area 
(https://apps-nefsc.fisheries.noaa.gov/psb/surveys/MapperiframeWithText.html). The SMA is currently active from November 1 
through April 30 of each year and may be used by right whales for 
migrating. As noted above in the Summary of Request section, NMFS is 
proposing changes to the North Atlantic right whale speed rule (87 FR 
46921; August 1, 2022).
    The proposed project area (456.5 km\2\) spatially overlaps a 
portion of the migratory corridor BIA (269,488 km\2\ (66,591,935 
acres)) within which right whales migrate south to calving grounds 
generally in November and December. A northward right whale migration 
into feeding areas north of the project area occurs in March and April 
(LaBrecque et al., 2015; Van Parijs et al., 2015). The proposed project 
area is also in the vicinity of the currently established November 1st 
through April 30th Chesapeake Bay SMA (73 FR 60173; October 10, 2008), 
which may be used by right whales for various activities, including 
migration. Due to the current status of North Atlantic right whales, 
and the overlap of the proposed CVOW-C project with areas of biological 
significance (i.e., a migratory corridor), the potential impacts of the 
proposed project on right whales warrant particular attention.
    In late fall, a portion of the right whale population (including 
pregnant females) typically departs the feeding grounds in the North 
Atlantic, moves south along the migratory corridor BIA, including 
through the proposed project area, to right whale calving grounds off 
Georgia and Florida. Right whales feed primarily on the copepod, 
Calanus finmarchicus, a species whose availability and distribution has 
changed both spatially and temporally over the last decade due to an 
oceanographic regime shift that has been ultimately linked to climate 
change (Meyer-Gutbrod et al., 2021; Record et al., 2019; Sorochan et 
al., 2019). This distribution change in prey availability has led to 
shifts in right whale habitat-use patterns over the same time period 
(Davis et al., 2020;

[[Page 28675]]

Meyer-Gutbrod et al., 2022; Quintano-Rizzo et al., 2021, O'Brien et 
al., 2022) with reduced use of foraging habitats in the Great South 
Channel and Bay of Fundy and increased use of habitats within Cape Cod 
Bay and a region south of Martha's Vineyard and Nantucket Islands 
(Stone et al., 2017; Mayo et al., 2018; Ganley et al., 2019; Record et 
al., 2019; Meyer-Gutbrod et al., 2021); these foraging habitats are all 
located several hundred kilometers north of the project area. Passive 
acoustic monitoring data demonstrates that since 2010, North Atlantic 
right whale use of the mid-Atlantic and southeast has increased (Davis 
et al., 2017). Observations of these transitions in right whale habitat 
use, variability in seasonal presence in identified core habitats, and 
utilization of habitat outside of previously focused survey effort 
prompted the formation of a NMFS' Expert Working Group, which 
identified current data collection efforts, data gaps, and provided 
recommendations for future survey and research efforts (Oleson et al., 
2020). Recent research indicates understanding of their movement 
patterns remains incomplete and not all of the population undergoes a 
consistent annual migration (Davis et al., 2017; Gowan et al., 2019; 
Krzystan et al., 2018). Non-calving females may remain in the feeding 
grounds, during the winter in the years preceding and following the 
birth of a calf to increase their energy stores (Gowen et al., 2019).
    North Atlantic right whale presence within the CVOW-C project area 
is predominantly seasonal with individuals likely to be transient and 
migrating through the area. The highest density months for North 
Atlantic right whales in this area are November through April, however, 
mitigation measures include a restriction on pile driving during this 
time period. Right whales have also been acoustically detected off 
coastal Virginia year-round with detections during the late fall 
(October-December) and late winter/early spring (February-March) 
(Salisbury et al., 2016). Density data from Roberts and Halpin (2022) 
confirm, of the months planned for construction (May through October), 
the highest average density of right whales in the CVOW-C project area 
occurs in May (0.00015 individuals/km\2\). However, based upon 
sightings and acoustic detections, right whales are likely to be 
present to some degree in or near the proposed project area throughout 
the year (Salisbury et al., 2016; Davis et al., 2017; Cotter, 2019), 
though we do not expect that the right whale presence would be in the 
larger numbers typically associated with a foraging or calving ground.
    Elevated right whale mortalities have occurred since June 7, 2017, 
along the U.S. and Canadian coast, with the leading category for the 
cause of death for this UME determined to be ``human interaction,'' 
specifically from entanglements or vessel strikes. As of April 13, 
2023, there have been 36 confirmed mortalities (dead stranded or 
floaters), 0 pending mortalities, and 33 seriously injured free-
swimming whales for a total of 69 whales. As of October 14, 2022, the 
UME also considers animals (n=29) with sub-lethal injury or illness 
(called ``morbidity'') bringing the total number of whales in the UME 
to 98. Approximately 42 percent of the population is known to be in 
reduced health (Hamilton et al., 2021), likely contributing to smaller 
body sizes at maturation, making them more susceptible to threats and 
reducing fecundity (Moore et al., 2021; Reed et al., 2022; Stewart et 
al., 2022). More information about the North Atlantic right whale UME 
is available online at: www.fisheries.noaa.gov/national/marine-life-distress/2017-2021-north-atlantic-right-whale-unusual-mortality-event.

Humpback Whale

    Humpback whales are found worldwide in all oceans, but were listed 
as endangered under the Endangered Species Conservation Act (ESCA) in 
June 1970. In 1973, the ESA replaced the ESCA, and humpbacks continued 
to be listed as endangered.
    On September 8, 2016, NMFS divided the once single species into 14 
distinct population segments (DPS), removed the species-level listing, 
and, in its place, listed four DPSs as endangered and one DPS as 
threatened (81 FR 62259; September 8, 2016). The remaining nine DPSs 
were not listed. The West Indies DPS, which is not listed under the 
ESA, is the only DPS of humpback whales that is expected to occur in 
the project area. Bettridge et al. (2015) estimated the size of the 
West Indies DPS population at 12,312 (95 percent confidence interval 
(CI) 8,688-15,954) whales in 2004-05, which is consistent with previous 
population estimates of approximately 10,000-11,000 whales (Smith et 
al., 1999; Stevick et al., 2003) and the increasing trend for the West 
Indies DPS (Bettridge et al., 2015).
    Humpback whales are migratory off coastal Virginia, moving 
seasonally between northern feeding grounds in New England and southern 
calving grounds in the West Indies (Hayes et al., 2022). However, not 
all humpback whales migrate to the Caribbean during the winter as 
individuals are sighted in mid- to high-latitude areas during this 
season (Swingle et al., 1993; Davis et al., 2020). In addition to a 
migratory pathway, the mid-Atlantic region also represents a 
supplemental winter feeding ground for juveniles and mature whales 
(Barco et al., 2002). Records of humpback whales off the U.S. mid-
Atlantic coast (New Jersey south to North Carolina) suggest that these 
waters are used as a winter feeding ground from December through March 
(Mallette et al., 2017; Barco et al., 2002; LaBrecque et al., 2015) and 
represent important habitat for juveniles, in particular (Swingle et 
al., 1993; Wiley et al., 1995). Mallette et al. (2017) documented site 
fidelity of individual humpback whales to coastal Virginia waters 
across seasons and years from 2012-2017. Based upon the analysis of 
stomach contents from humpback whales that have previously stranded in 
the coastal Virginia area, whales may feed upon Atlantic menhaden and 
bay anchovy off coastal Virginia (Mallette et al., 2017).
    Since January 2016, elevated humpback whale mortalities along the 
Atlantic coast from Maine to Florida led to the declaration of a UME. 
Partial or full necropsy examinations have been conducted on 
approximately half of the 191 known cases (as of April 13, 2023). Of 
the whales examined (approximately 90), about 40 percent had evidence 
of human interaction, either ship strike or entanglement (https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2023-humpback-whale-unusual-mortality-event-along-atlantic-coast). While a 
portion of the whales have shown evidence of pre-mortem vessel strike, 
this finding is not consistent across all whales examined and more 
research is needed. NOAA is consulting with researchers that are 
conducting studies on the humpback whale populations, and these efforts 
may provide information on changes in whale distribution and habitat 
use that could provide additional insight into how these vessel 
interactions occurred. More information is available at: https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2023-humpback-whale-unusual-mortality-event-along-atlantic-coast.
    Since December 1, 2022, the number of humpback strandings along the 
mid-Atlantic coast, including Virginia off Virginia Beach, has been 
elevated. In some cases, the cause of death is not yet known. In 
others, vessel strike has been deemed the cause of death. As the 
humpback whale population has grown,

[[Page 28676]]

they are seen more often in the Mid-Atlantic. Along the New York/New 
Jersey/Virginia shore, these whales may be following their prey which 
are reportedly close to shore in the winter. These prey also attract 
fish that are of interest to recreational and commercial fishermen. 
This increases the number of boats in these areas. More whales in the 
water in areas traveled by boats of all sizes increases the risk of 
vessel strikes. Vessel strikes and entanglement in fishing gear are the 
greatest human threats to large whales.

Fin Whale

    Fin whales frequently occur in the waters of the U.S. Atlantic 
Exclusive Economic Zone (EEZ), principally from Cape Hatteras, North 
Carolina northward and are distributed in both continental shelf and 
deep water habitats (Hayes et al., 2022). Although fin whales are 
present north of the 35-degree latitude region in every season and are 
broadly distributed throughout the western North Atlantic for most of 
the year, densities vary seasonally (Edwards et al., 2015; Hayes et 
al., 2022). Acoustic detections suggest year-round presence in Virginia 
waters, with the greatest number of detections occurring from August 
through April (Davis et al., 2020). Acoustic observations of fin whale 
singers from both the Atlantic Continental Shelf and deep-ocean areas 
provide evidence of fin whale singing throughout these regions year-
round and support the conclusion that male fin whales are broadly 
distributed throughout the western North Atlantic for most of the year 
(Watkins et al., 1987; Clark and Gagnon, 2002; Morano et al., 2012; 
Davis et al., 2020; Hayes et al., 2022).
    The New England area represents a major feeding ground for fin 
whales, with two known foraging BIAs in the general area. Fin whales 
typically feed in the Gulf of Maine and the waters surrounding New 
England, but their mating and calving (and general wintering) areas are 
largely unknown (Hain et al., 1992, Hayes et al., 2022). Hain et al. 
(1992) suggested calving occurs in the mid-Atlantic region from October 
through January, yet this remains to be confirmed. However, given the 
more southerly location of the Virginia Lease Area (located 
approximately 516 km (320.6 mi) away from the Montauk Point BIA (2,933 
km\2\ (724,760.1 acres); Hain et al., 1992; LaBrecque et al., 2015) and 
approximately 695 km (431.9 mi) from the southern Gulf of Maine BIA 
(18,015 km\2\; 4,451,603.4 acres). Therefore, there would be no overlap 
from the CVOW-C project with either of the fin whale feeding BIAs.

Minke Whale

    Minke whales are common and widely distributed throughout the U.S. 
Atlantic EEZ (Cetacean and Turtle Assessment Program (CETAP), 1982; 
Hayes et al., 2022), although their distribution has a strong seasonal 
component. Individuals have often been detected acoustically in shelf 
waters from spring to fall and more often detected in deeper offshore 
waters from winter to spring (Risch et al., 2013). Minke whales are 
abundant in New England waters from May through September (Pittman et 
al., 2006; Waring et al., 2014), yet largely absent from these areas 
during the winter, suggesting the possible existence of a migratory 
corridor (LaBrecque et al., 2015). A migratory route for minke whales 
transiting between northern feeding grounds and southern breeding areas 
may exist to the east of the proposed project area, as minke whales may 
track warmer waters along the continental shelf while migrating (Risch 
et al., 2014). Overall, minke whale use of the project area is likely 
highest during winter months when foundation installation would not be 
occurring. No mating or calving grounds have been identified along the 
U.S. Atlantic coast (LaBrecque et al., 2015).
    There are two minke whale feeding BIAs identified in the southern 
and southwestern section of the Gulf of Maine, including Georges Bank, 
the Great South Channel, Cape Cod Bay and Massachusetts Bay, Stellwagen 
Bank, Cape Anne, and Jeffreys Ledge from March through November, 
annually (LeBrecque et al., 2015). However, these BIAs are located 
north of the CVOW-C project area, at approximately 656 km (407.6 mi) 
from the CVOW-C project area to the most southern BIA and would not 
overlap the CVOW-C project area.
    Since January 2017, elevated minke whale mortalities detected along 
the Atlantic coast from Maine through South Carolina resulted in the 
declaration of a UME. As of April 13, 2023, a total of 142 minke whales 
have stranded during this UME. Full or partial necropsy examinations 
were conducted on more than 60 percent of the whales. Preliminary 
findings have shown evidence of human interactions or infectious 
disease in several of the whales, but these findings are not consistent 
across all of the whales examined, so more research is needed. This UME 
has been declared non-active and is pending closure. More information 
is available at: https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2022-minke-whale-unusual-mortality-event-along-atlantic-coast.

Sei Whale

    The Nova Scotia stock of sei whales can be found in deeper waters 
of the continental shelf edge of the eastern United States and 
northeastward to south of Newfoundland (Mitchell, 1975; Hain et al., 
1985; Hayes et al., 2022). During spring and summer, the stock is 
mainly concentrated in northern feeding areas, including the Scotian 
Shelf (Mitchell and Chapman, 1977), the Gulf of Maine, Georges Bank, 
the Northeast Channel, and south of Nantucket (CETAP, 1982; Kraus et 
al., 2016; Roberts et al., 2016; Palka et al., 2017; Cholewiak et al., 
2018; Hayes et al., 2022). Sei whales have been detected acoustically 
along the Atlantic Continental Shelf and Slope from south of Cape 
Hatteras, North Carolina to the Davis Strait, with acoustic occurrence 
increasing in the mid-Atlantic region since 2010 (Davis et al., 2020). 
Although their migratory movements are not well understood, sei whales 
are believed to migrate north in June and July to feeding areas and 
south in September and October to breeding areas (Mitchell, 1975; 
CETAP, 1982; Davis et al., 2020). Davis et al. (2020) acoustically 
detected sei whales in offshore waters of the mid-Atlantic region 
during the winter months. Very few sei whales were detected in the mid-
Atlantic during the summer (the primary time of year when foundation 
installation would be occurring), with the exception of a detection 
that lasted for two days off Virginia. Although sei whales generally 
occur offshore, individuals may also move into shallower, more inshore 
waters (Payne et al., 1990; Halpin et al., 2009; Hayes et al., 2022).
    A sei whale feeding BIA occurs in New England waters from May 
through November (LaBrecque et al., 2015). This BIA is located 
approximately 600 km (372.8 mi) northeast of the project area and is 
not expected to be impacted by project activities related to CVOW-C.

Phocid Seals

    Since June 2022, elevated numbers of harbor seal and gray seal 
mortalities have occurred across the southern and central coast of 
Maine. This event has been declared a UME. Preliminary testing of 
samples has found some harbor and gray seals positive for highly 
pathogenic avian influenza. While the UME is not occurring in the CVOW-
C project area, the populations affected by the UME are the same as 
those potentially affected by the project.

[[Page 28677]]

However, due to the two states being approximately 677.6 km (421 mi) 
apart, by water (from the most northern point of Virginia to the most 
southern point of Maine), NMFS does not expect that this UME would be 
further conflated by the proposed activities related to the CVOW-C 
project. Information on this UME is available online at: https://www.fisheries.noaa.gov/2022-2023-pinniped-unusual-mortality-event-along-maine-coast.
    The above event was preceded by a different UME, occurring from 
2018-2020 (closure of the 2018-2020 UME is pending). Beginning in July 
2018, elevated numbers of harbor seal and gray seal mortalities 
occurred across Maine, New Hampshire, and Massachusetts. Additionally, 
stranded seals have shown clinical signs as far south as Virginia, 
although not in elevated numbers, therefore the UME investigation 
encompassed all seal strandings from Maine to Virginia. A total of 
3,152 reported strandings (of all species) occurred from July 1, 2018, 
through March 13, 2020. Full or partial necropsy examinations have been 
conducted on some of the seals and samples have been collected for 
testing. Based on tests conducted thus far, the main pathogen found in 
the seals is phocine distemper virus. NMFS is performing additional 
testing to identify any other factors that may be involved in this UME, 
which is pending closure. Information on this UME is available online 
at: https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 8.

                  Table 8--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen   7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Twenty-one marine mammal species (19 cetacean species (5 mysticetes and 
14 odontocetes) and 2 pinniped species (both phocid), consisting of 22 
total stocks) have the reasonable potential to co-occur with the 
proposed project activities (Table 7).
    NMFS notes that in 2019, Southall et al. recommended new names for 
hearing groups that are widely recognized. However, this new hearing 
group classification does not change the weighting functions or 
acoustic thresholds (i.e., the weighting functions and thresholds in 
Southall et al. (2019) are identical to NMFS 2018 Revised Technical 
Guidance). When NMFS updates our Technical Guidance, we will be 
adopting the updated Southall et al. (2019) hearing group 
classification.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take of Marine Mammals section later in 
this document includes a quantitative analysis of the number of 
individuals that are expected to be taken by this activity. The 
Negligible Impact Analysis and Determination section considers the 
content of this section, the Estimated Take of Marine Mammals section, 
and the Proposed Mitigation section, to draw conclusions regarding the 
likely impacts of these activities on the reproductive success or 
survivorship of individuals and how those impacts on individuals are 
likely to impact marine mammal species or stocks. General background 
information on marine mammal hearing was provided previously (see the 
Description of Marine Mammals in the Area of Specified Activities 
section). Here, the potential effects of sound on marine mammals are 
discussed.
    Dominion Energy has requested authorization to take marine mammals 
incidental to construction activities associated within the CVOW-C 
project area. In the ITA application, Dominion Energy presented 
analyses of potential impacts to marine mammals from use of acoustic 
sources. NMFS carefully reviewed the information provided by Dominion 
Energy and independently

[[Page 28678]]

reviewed applicable scientific research and literature and other 
information to evaluate the potential effects of Dominion Energy's 
activities on marine mammals.
    The proposed activities include the placement of up to 179 
permanent foundations (176 WTGs and 3 OSSs), temporary nearshore cable 
landfall activities (i.e., cofferdams and goal posts), and site 
characterization surveys (i.e., HRG surveys). There are a variety of 
types and degrees of effects to marine mammals, prey species, and 
habitat that could occur as a result of the project. Below we provide a 
brief description of the types of sound sources that would be used in 
the project, the types of impacts that can potentially result from 
these sources and types of activities, and a brief discussion of the 
anticipated impacts on marine mammals from the CVOW-C project 
specifically, with consideration of the proposed mitigation measures.

Description of Sound Sources

    This section contains a brief technical background on sound, on the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document. For general 
information on sound and its interaction with the marine environment, 
please see, e.g., Au and Hastings (2008); Richardson et al. (1995); 
Urick (1983) as well as the Discovery of Sound in the Sea (DOSITS) 
website at https://dosits.org/.
    Sound is a vibration that travels as an acoustic wave through a 
medium such as a gas, liquid or solid. Sound waves alternately compress 
and decompress the medium as the wave travels. These compressions and 
decompressions are detected as changes in pressure by aquatic life and 
man-made sound receptors such as hydrophones (underwater microphones). 
In water, sound waves radiate in a manner similar to ripples on the 
surface of a pond and may be either directed in a beam (narrow beam or 
directional sources) or sound beams may radiate in all directions 
(omnidirectional sources).
    Sound travels in water more efficiently than almost any other form 
of energy, making the use of acoustics ideal for the aquatic 
environment and its inhabitants. In seawater, sound travels at roughly 
1,500 meters per second (m/s). In air, sound waves travel much more 
slowly at about 340 m/s. However, the speed of sound can vary by a 
small amount based on characteristics of the transmission medium such 
as water temperature and salinity.
    The basic components of a sound wave are frequency, wavelength, 
velocity, and amplitude. Frequency is the number of pressure waves that 
pass by a reference point per unit of time and is measured in Hz or 
cycles per second. Wavelength is the distance between two peaks or 
corresponding points of a sound wave (length of one cycle). Higher 
frequency sounds have shorter wavelengths than lower frequency sounds 
and typically attenuate (decrease) more rapidly except in certain cases 
in shallower water. The intensity (or amplitude) of sounds are measured 
in decibels (dB), which are a relative unit of measurement that is used 
to express the ratio of one value of a power or field to another. 
Decibels are measured on a logarithmic scale, so a small change in dB 
corresponds to large changes in sound pressure. For example, a 10 dB 
increase is a ten-fold increase in acoustic power. A 20 dB increase is 
then a 100-fold increase in power and a 30 dB increase is a 1000-fold 
increase in power. However, a ten-fold increase in acoustic power does 
not mean that the sound is perceived as being 10 times louder. Decibels 
are a relative unit comparing two pressures; therefore, a reference 
pressure must always be indicated. For underwater sound, this is 1 
microPascal ([mu]Pa). For in-air sound, the reference pressure is 20 
microPascal ([mu]Pa). The amplitude of a sound can be presented in 
various ways; however, NMFS typically considers three metrics.
    Sound exposure level (SEL) represents the total energy in a stated 
frequency band over a stated time interval or event and considers both 
amplitude and duration of exposure (represented as dB re 1 [mu]Pa2-s). 
SEL is a cumulative metric; it can be accumulated over a single pulse 
(for pile driving this is often referred to as single-strike SEL; 
SELss) or calculated over periods containing multiple pulses 
(SELcum). Cumulative SEL represents the total energy 
accumulated by a receiver over a defined time window or during an 
event. The SEL metric is useful because it allows sound exposures of 
different durations to be related to one another in terms of total 
acoustic energy. The duration of a sound event and the number of 
pulses, however, should be specified as there is no accepted standard 
duration over which the summation of energy is measured. Sounds are 
typically classified by their spectral and temporal properties.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Root mean square is calculated by squaring 
all of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1983). Root mean square accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper, 2005). This measurement is often 
used in the context of discussing behavioral effects, in part because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units than by peak pressures.
    Peak sound pressure (also referred to as zero-to-peak sound 
pressure or 0-pk) is the maximum instantaneous sound pressure 
measurable in the water at a specified distance from the source, and is 
represented in the same units as the rms sound pressure. Along with 
SEL, this metric is used in evaluating the potential for PTS (permanent 
threshold shift) and TTS (temporary threshold shift).
    Sounds can be either impulsive or non-impulsive. The distinction 
between these two sound types is important because they have differing 
potential to cause physical effects, particularly with regard to 
hearing (e.g., Ward, 1997 in Southall et al., 2007). Please see NMFS et 
al. (2018) and Southall et al. (2007, 2019) for an in-depth discussion 
of these concepts. Impulsive sound sources (e.g., airguns, explosions, 
gunshots, sonic booms, impact pile driving) produce signals that are 
brief (typically considered to be less than 1 second), broadband, 
atonal transients (American National Standards Institute (ANSI), 1986, 
2005; Harris, 1998; National Institute for Occupational Safety and 
Health (NIOSH), 1998; International Organization for Standardization 
(ISO), 2003) and occur either as isolated events or repeated in some 
succession. Impulsive sounds are all characterized by a relatively 
rapid rise from ambient pressure to a maximal pressure value followed 
by a rapid decay period that may include a period of diminishing, 
oscillating maximal and minimal pressures, and generally have an 
increased capacity to induce physical injury as compared with sounds 
that lack these features. Impulsive sounds are typically intermittent 
in nature.
    Non-impulsive sounds can be tonal, narrowband, or broadband, brief 
or prolonged, and may be either continuous or intermittent (ANSI, 1995; 
NIOSH, 1998). Some of these non-impulsive sounds can be transient 
signals of short duration but without the essential properties of 
pulses (e.g., rapid rise time). Examples of non-impulsive

[[Page 28679]]

sounds include those produced by vessels, aircraft, machinery 
operations such as drilling or dredging, vibratory pile driving, and 
active sonar systems.
    Sounds are also characterized by their temporal component. 
Continuous sounds are those whose sound pressure level remains above 
that of the ambient sound with negligibly small fluctuations in level 
(NIOSH, 1998; ANSI, 2005) while intermittent sounds are defined as 
sounds with interrupted levels of low or no sound (NIOSH, 1998). NMFS 
identifies Level B harassment thresholds based on if a sound is 
continuous or intermittent.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound, which is 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al., 1995). The sound level of a region 
is defined by the total acoustical energy being generated by known and 
unknown sources. These sources may include physical (e.g., wind and 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
(e.g., vessels, dredging, construction) sound. A number of sources 
contribute to ambient sound, including wind and waves, which are a main 
source of naturally occurring ambient sound for frequencies between 200 
Hz and 50 kHz (International Council for the Exploration of the Sea 
(ICES), 1995). In general, ambient sound levels tend to increase with 
increasing wind speed and wave height. Precipitation can become an 
important component of total sound at frequencies above 500 Hz and 
possibly down to 100 Hz during quiet times. Marine mammals can 
contribute significantly to ambient sound levels as can some fish and 
snapping shrimp. The frequency band for biological contributions is 
from approximately 12 Hz to over 100 kHz. Sources of ambient sound 
related to human activity include transportation (surface vessels), 
dredging and construction, oil and gas drilling and production, 
geophysical surveys, sonar, and explosions. Vessel noise typically 
dominates the total ambient sound for frequencies between 20 and 300 
Hz. In general, the frequencies of anthropogenic sounds are below 1 
kHz, and if higher frequency sound levels are created, they attenuate 
rapidly.
    The sum of the various natural and anthropogenic sound sources that 
comprise ambient sound at any given location and time depends not only 
on the source levels (as determined by current weather conditions and 
levels of biological and human activity) but also on the ability of 
sound to propagate through the environment. In turn, sound propagation 
is dependent on the spatially and temporally varying properties of the 
water column and sea floor and is frequency-dependent. As a result of 
the dependence on a large number of varying factors, ambient sound 
levels can be expected to vary widely over both coarse and fine spatial 
and temporal scales. Sound levels at a given frequency and location can 
vary by 10-20 dB from day to day (Richardson et al., 1995). The result 
is that, depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals. Underwater ambient sound in the Atlantic Ocean offshore of 
Virginia comprises sounds produced by a number of natural and 
anthropogenic sources. Human-generated sound is a significant 
contributor to the acoustic environment in the project location.
    Pile driving sounds are broadband, omni-directional sound sources. 
Pile driving noise has the potential to result in harassment to marine 
mammals if the animal is close enough to the sound source (with the 
distances necessary to cause harassment dependent on source levels and 
transmission loss rates). HRG sources; however, are more complex as 
they vary widely (e.g., side scan sonars, sub-bottom profilers, 
boomers, and sparkers). Recently, Ruppel et al. (2022) categorized HRG 
sources into four tiers based on their potential to affect marine 
animals. All HRG sources proposed for use by Dominion Energy fall into 
the Tier 3 or Tier 4 category (note Tier 1 is the most impactful 
category containing high-energy airguns). Tier 4 includes most high-
resolution geophysical, oceanographic, and communication/tracking 
sources, which are considered unlikely to result in incidental take of 
marine mammals and therefore termed de minimis. Tier 3 covers most 
remaining non-airgun seismic sources, which either have characteristics 
that do not meet the de minimis category (e.g., some sparkers), but 
have anticipated impacts less than airguns and for which additional 
mitigation may in some cases be able to avoid the likelihood of take, 
or could not be fully evaluated in the paper (e.g., bubble guns, some 
boomers). Some sparkers fell into Tier 3, as the study found that most 
sparkers lack the frequency, beamwidth, and degree of exposure 
characteristics to automatically meet the de minimis criteria.

Potential Effects of Underwater Sound on Marine Mammals and Their 
Habitat

    Anthropogenic sounds cover a broad range of frequencies and sound 
levels and can have a range of highly variable impacts on marine life 
from none or minor to potentially severe responses depending on 
received levels, duration of exposure, behavioral context, and various 
other factors. Broadly, underwater sound from active acoustic sources, 
such as those in the CVOW-C project, can potentially result in one or 
more of the following: temporary or permanent hearing impairment, non-
auditory physical or physiological effects, behavioral disturbance, 
stress, and masking (Richardson et al., 1995; Gordon et al., 2003; 
Nowacek et al., 2007; Southall et al., 2007; G[ouml]tz et al., 2009). 
Non-auditory physiological effects or injuries that theoretically might 
occur in marine mammals exposed to high level underwater sound or as a 
secondary effect of extreme behavioral reactions (e.g., change in dive 
profile as a result of an avoidance reaction) caused by exposure to 
sound include neurological effects, bubble formation, resonance 
effects, and other types of organ or tissue damage (Cox et al., 2006; 
Southall et al., 2007; Zimmer and Tyack, 2007; Tal et al., 2015).
    In general, the degree of effect of an acoustic exposure is 
intrinsically related to the signal characteristics, received level, 
distance from the source, and duration of the sound exposure, in 
addition to the contextual factors of the receiver (e.g., behavioral 
state at time of exposure, age class, etc.). In general, sudden, high 
level sounds can cause hearing loss as can longer exposures to lower 
level sounds. Moreover, any temporary or permanent loss of hearing will 
occur almost exclusively for noise within an animal's hearing range. We 
describe below the specific manifestations of acoustic effects that may 
occur based on the activities proposed by Dominion Energy.
    Richardson et al. (1995) described zones of increasing intensity of 
effect that might be expected to occur in relation to distance from a 
source and assuming that the signal is within an animal's hearing 
range. First (at the greatest distance) is the area within which the 
acoustic signal would be audible (potentially perceived) to the animal 
but not strong enough to elicit any overt behavioral or physiological 
response. The next zone (closer to the receiving animal) corresponds 
with the area where the signal is audible to the animal and of 
sufficient intensity to elicit behavioral or physiological 
responsiveness. The third is a zone

[[Page 28680]]

within which, for signals of high intensity, the received level is 
sufficient to potentially cause discomfort or tissue damage to auditory 
or other systems. Overlaying these zones to a certain extent is the 
area within which masking (i.e., when a sound interferes with or masks 
the ability of an animal to detect a signal of interest that is above 
the absolute hearing threshold) may occur; the masking zone may be 
highly variable in size.
    Below, we provide additional detail regarding potential impacts on 
marine mammals and their habitat from noise in general, starting with 
hearing impairment, as well as from the specific activities Dominion 
Energy plans to conduct, to the degree it is available (noting that 
there is limited information regarding the impacts of offshore wind 
construction on marine mammals).
Hearing Threshold Shift
    Marine mammals exposed to high-intensity sound or to lower-
intensity sound for prolonged periods can experience hearing threshold 
shift (TS), which NMFS defines as a change, usually an increase, in the 
threshold of audibility at a specified frequency or portion of an 
individual's hearing range above a previously established reference 
level expressed in decibels (NMFS, 2018). Threshold shifts can be 
permanent, in which case there is an irreversible increase in the 
threshold of audibility at a specified frequency or portion of an 
individual's hearing range or temporary, in which there is reversible 
increase in the threshold of audibility at a specified frequency or 
portion of an individual's hearing range and the animal's hearing 
threshold would fully recover over time (Southall et al., 2019). 
Repeated sound exposure that leads to TTS could cause PTS.
    When PTS occurs, there can be physical damage to the sound 
receptors in the ear (i.e., tissue damage) whereas TTS represents 
primarily tissue fatigue and is reversible (Henderson et al., 2008). In 
addition, other investigators have suggested that TTS is within the 
normal bounds of physiological variability and tolerance and does not 
represent physical injury (e.g., Ward, 1997; Southall et al., 2019). 
Therefore, NMFS does not consider TTS to constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, and there is no PTS data for cetaceans. However, 
such relationships are assumed to be similar to those in humans and 
other terrestrial mammals. Noise exposure can result in either a 
permanent shift in hearing thresholds from baseline (PTS; a 40 dB 
threshold shift approximates a PTS onset; e.g., Kryter et al., 1966; 
Miller, 1974; Henderson et al., 2008) or a temporary, recoverable shift 
in hearing that returns to baseline (a 6 dB threshold shift 
approximates a TTS onset; e.g., Southall et al., 2019). Based on data 
from terrestrial mammals, a precautionary assumption is that the PTS 
thresholds, expressed in the unweighted peak sound pressure level 
metric (PK), for impulsive sounds (such as impact pile driving pulses) 
are at least 6 dB higher than the TTS thresholds and the weighted PTS 
cumulative sound exposure level thresholds are 15 (impulsive sound) to 
20 (non-impulsive sounds) dB higher than TTS cumulative sound exposure 
level thresholds (Southall et al., 2019). Given the higher level of 
sound or longer exposure duration necessary to cause PTS as compared 
with TTS, PTS is less likely to occur as a result of these activities, 
but it is possible and a small amount has been proposed for 
authorization for several species.
    TTS is the mildest form of hearing impairment that can occur during 
exposure to sound, with a TTS of 6 dB considered the minimum threshold 
shift clearly larger than any day-to-day or session-to-session 
variation in a subject's normal hearing ability (Schlundt et al., 2000; 
Finneran et al., 2000; Finneran et al., 2002). While experiencing TTS, 
the hearing threshold rises, and a sound must be at a higher level in 
order to be heard. In terrestrial and marine mammals, TTS can last from 
minutes or hours to days (in cases of strong TTS). In many cases, 
hearing sensitivity recovers rapidly after exposure to the sound ends. 
There is data on sound levels and durations necessary to elicit mild 
TTS for marine mammals, but recovery is complicated to predict and 
dependent on multiple factors.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to serious 
depending on the degree of interference of marine mammals hearing. For 
example, a marine mammal may be able to readily compensate for a brief, 
relatively small amount of TTS in a non-critical frequency range that 
occurs during a time where ambient noise is lower and there are not as 
many competing sounds present. Alternatively, a larger amount and 
longer duration of TTS sustained during time when communication is 
critical (e.g., for successful mother/calf interactions, consistent 
detection of prey) could have more serious impacts.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor 
porpoise, and Yangtze finless porpoise (Neophocaena asiaeorientalis)) 
and six species of pinnipeds (northern elephant seal (Mirounga 
angustirostris), harbor seal, ring seal, spotted seal, bearded seal, 
and California sea lion (Zalophus californianus)) that were exposed to 
a limited number of sound sources (i.e., mostly tones and octave-band 
noise with limited number of exposure to impulsive sources such as 
seismic airguns or impact pile driving) in laboratory settings 
(Southall et al., 2019). There is currently no data available on noise-
induced hearing loss for mysticetes. For summaries of data on TTS or 
PTS in marine mammals or for further discussion of TTS or PTS onset 
thresholds, please see Southall et al. (2019) and NMFS (2018).
    Recent studies with captive odontocete species (bottlenose dolphin, 
harbor porpoise, beluga, and false killer whale) have observed 
increases in hearing threshold levels when individuals received a 
warning sound prior to exposure to a relatively loud sound (Nachtigall 
and Supin, 2013, 2015; Nachtigall et al., 2016a, 2016b, 2016c; 
Finneran, 2018; Nachtigall et al., 2018). These studies suggest that 
captive animals have a mechanism to reduce hearing sensitivity prior to 
impending loud sounds. Hearing change was observed to be frequency 
dependent and Finneran (2018) suggests hearing attenuation occurs 
within the cochlea or auditory nerve. Based on these observations on 
captive odontocetes, the authors suggest that wild animals may have a 
mechanism to self-mitigate the impacts of noise exposure by dampening 
their hearing during prolonged exposures of loud sound or if 
conditioned to anticipate intense sounds (Finneran, 2018, Nachtigall et 
al., 2018).
Behavioral Effects
    Exposure of marine mammals to sound sources can result in, but is 
not limited to, no response or any of the following observable 
responses: increased alertness; orientation or attraction to a sound 
source; vocal modifications; cessation of feeding; cessation of social 
interaction; alteration of movement or diving behavior; habitat 
abandonment (temporary or permanent);

[[Page 28681]]

and in severe cases, panic, flight, stampede, or stranding, potentially 
resulting in death (Southall et al., 2007). A review of marine mammal 
responses to anthropogenic sound was first conducted by Richardson 
(1995). More recent reviews address studies conducted since 1995 and 
focused on observations where the received sound level of the exposed 
marine mammal(s) was known or could be estimated (Nowacek et al., 2007; 
DeRuiter et al., 2012 and 2013; Ellison et al., 2012; Gomez et al., 
2016). Gomez et al. (2016) conducted a review of the literature 
considering the contextual information of exposure in addition to 
received level and found that higher received levels were not always 
associated with more severe behavioral responses and vice versa. 
Southall et al. (2021) states that results demonstrate that some 
individuals of different species display clear yet varied responses, 
some of which have negative implications while others appear to 
tolerate high levels and that responses may not be fully predictable 
with simple acoustic exposure metrics (e.g., received sound level). 
Rather, the authors state that differences among species and 
individuals along with contextual aspects of exposure (e.g., behavioral 
state) appear to affect response probability. Behavioral responses to 
sound are highly variable and context-specific. Many different 
variables can influence an animal's perception of and response to 
(nature and magnitude) an acoustic event. An animal's prior experience 
with a sound or sound source affects whether it is less likely 
(habituation) or more likely (sensitization) to respond to certain 
sounds in the future (animals can also be innately predisposed to 
respond to certain sounds in certain ways) (Southall et al., 2019). 
Related to the sound itself, the perceived nearness of the sound, 
bearing of the sound (approaching vs. retreating), the similarity of a 
sound to biologically relevant sounds in the animal's environment 
(i.e., calls of predators, prey, or conspecifics), and familiarity of 
the sound may affect the way an animal responds to the sound (Southall 
et al., 2007, DeRuiter et al., 2013). Individuals (of different age, 
gender, reproductive status, etc.) among most populations will have 
variable hearing capabilities, and differing behavioral sensitivities 
to sounds that will be affected by prior conditioning, experience, and 
current activities of those individuals. Often, specific acoustic 
features of the sound and contextual variables (i.e., proximity, 
duration, or recurrence of the sound or the current behavior that the 
marine mammal is engaged in or its prior experience), as well as 
entirely separate factors such as the physical presence of a nearby 
vessel, may be more relevant to the animal's response than the received 
level alone. Overall, the variability of responses to acoustic stimuli 
depends on the species receiving the sound, the sound source, and the 
social, behavioral, or environmental contexts of exposure (e.g., 
DeRuiter et al., 2012). For example, Goldbogen et al. (2013) 
demonstrated that individual behavioral state was critically important 
in determining response of blue whales to sonar, noting that some 
individuals engaged in deep (greater than 50 m) feeding behavior had 
greater dive responses than those in shallow feeding or non-feeding 
conditions. Some blue whales in the Goldbogen et al. (2013) study that 
were engaged in shallow feeding behavior demonstrated no clear changes 
in diving or movement even when received levels were high (~160 dB re 
1[micro]Pa) for exposures to 3-4 kHz sonar signals, while deep feeding 
and non-feeding whales showed a clear response at exposures at lower 
received levels of sonar and pseudorandom noise. Southall et al. (2011) 
found that blue whales had a different response to sonar exposure 
depending on behavioral state, more pronounced when deep feeding/travel 
modes than when engaged in surface feeding.
    With respect to distance influencing disturbance, DeRuiter et al. 
(2013) examined behavioral responses of Cuvier's beaked whales to mid-
frequency sonar and found that whales responded strongly at low 
received levels (89-127 dB re 1[micro]Pa) by ceasing normal fluking and 
echolocation, swimming rapidly away, and extending both dive duration 
and subsequent non-foraging intervals when the sound source was 3.4-9.5 
km away. Importantly, this study also showed that whales exposed to a 
similar range of received levels (78-106 dB re 1[micro]Pa) from distant 
sonar exercises (118 km away) did not elicit such responses, suggesting 
that context may moderate reactions. Thus, distance from the source is 
an important variable in influencing the type and degree of behavioral 
response and this variable is independent of the effect of received 
levels (e.g., DeRuiter et al., 2013; Dunlop et al., 2017a, 2017b; 
Falcone et al., 2017; Dunlop et al., 2018; Southall et al., 2019).
    Ellison et al. (2012) outlined an approach to assessing the effects 
of sound on marine mammals that incorporates contextual-based factors. 
The authors recommend considering not just the received level of sound 
but also the activity the animal is engaged in at the time the sound is 
received, the nature and novelty of the sound (i.e., is this a new 
sound from the animal's perspective), and the distance between the 
sound source and the animal. They submit that this ``exposure 
context,'' as described, greatly influences the type of behavioral 
response exhibited by the animal. Forney et al. (2017) also point out 
that an apparent lack of response (e.g., no displacement or avoidance 
of a sound source) may not necessarily mean there is no cost to the 
individual or population, as some resources or habitats may be of such 
high value that animals may choose to stay, even when experiencing 
stress or hearing loss. Forney et al. (2017) recommend considering both 
the costs of remaining in an area of noise exposure such as TTS, PTS, 
or masking, which could lead to an increased risk of predation or other 
threats or a decreased capability to forage, and the costs of 
displacement, including potential increased risk of vessel strike, 
increased risks of predation or competition for resources, or decreased 
habitat suitable for foraging, resting, or socializing. This sort of 
contextual information is challenging to predict with accuracy for 
ongoing activities that occur over large spatial and temporal expanses. 
However, distance is one contextual factor for which data exist to 
quantitatively inform a take estimate, and the method for predicting 
Level B harassment in this rule does consider distance to the source. 
Other factors are often considered qualitatively in the analysis of the 
likely consequences of sound exposure where supporting information is 
available.
    Behavioral change, such as disturbance manifesting in lost foraging 
time, in response to anthropogenic activities is often assumed to 
indicate a biologically significant effect on a population of concern. 
However, individuals may be able to compensate for some types and 
degrees of shifts in behavior, preserving their health and thus their 
vital rates and population dynamics. For example, New et al. (2013) 
developed a model simulating the complex social, spatial, behavioral 
and motivational interactions of coastal bottlenose dolphins in the 
Moray Firth, Scotland, to assess the biological significance of 
increased rate of behavioral disruptions caused by vessel traffic. 
Despite a modeled scenario in which vessel traffic increased from 70 to 
470 vessels a year (a six-fold increase in vessel traffic) in response 
to the

[[Page 28682]]

construction of a proposed offshore renewables' facility, the dolphins' 
behavioral time budget, spatial distribution, motivations and social 
structure remained unchanged. Similarly, two bottlenose dolphin 
populations in Australia were also modeled over 5 years against a 
number of disturbances (Reed et al., 2020) and results indicate that 
habitat/noise disturbance had little overall impact on population 
abundances in either location, even in the most extreme impact 
scenarios modeled.
    Friedlaender et al. (2016) provided the first integration of direct 
measures of prey distribution and density variables incorporated into 
across-individual analyses of behavior responses of blue whales to 
sonar and demonstrated a fivefold increase in the ability to quantify 
variability in blue whale diving behavior. These results illustrate 
that responses evaluated without such measurements for foraging animals 
may be misleading, which again illustrates the context-dependent nature 
of the probability of response.
    The following subsections provide examples of behavioral responses 
that give an idea of the variability in behavioral responses that would 
be expected given the differential sensitivities of marine mammal 
species to sound, contextual factors, and the wide range of potential 
acoustic sources to which a marine mammal may be exposed. Behavioral 
responses that could occur for a given sound exposure should be 
determined from the literature that is available for each species, or 
extrapolated from closely related species when no information exists, 
along with contextual factors.

Avoidance and Displacement

    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
(Eschrichtius robustus) and humpback whales are known to change 
direction--deflecting from customary migratory paths--in order to avoid 
noise from airgun surveys (Malme et al., 1984; Dunlop et al., 2018). 
Avoidance is qualitatively different from the flight response but also 
differs in the magnitude of the response (i.e., directed movement, rate 
of travel, etc.). Avoidance may be short-term with animals returning to 
the area once the noise has ceased (e.g., Malme et al., 1984; Bowles et 
al., 1994; Goold, 1996; Stone et al., 2000; Morton and Symonds, 2002; 
Gailey et al., 2007; D[auml]hne et al., 2013; Russel et al., 2016). 
Longer-term displacement is possible, however, which may lead to 
changes in abundance or distribution patterns of the affected species 
in the affected region if habituation to the presence of the sound does 
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann 
et al., 2006; Forney et al., 2017). Avoidance of marine mammals during 
the construction of offshore wind facilities (specifically, impact pile 
driving) has been documented in the literature with some significant 
variation in the temporal and spatial degree of avoidance and with most 
studies focused on harbor porpoises as one of the most common marine 
mammals in European waters (e.g., Tougaard et al., 2009; D[auml]hne et 
al., 2013; Thompson et al., 2013; Russell et al., 2016; Brandt et al., 
2018).
    Available information on impacts to marine mammals from pile 
driving associated with offshore wind is limited to information on 
harbor porpoises and seals, as the vast majority of this research has 
occurred at European offshore wind projects where large whales and 
other odontocete species are uncommon. Harbor porpoises and harbor 
seals are considered to be behaviorally sensitive species (e.g., 
Southall et al., 2007) and the effects of wind farm construction in 
Europe on these species has been well documented. These species have 
received particular attention in European waters due to their abundance 
in the North Sea (Hammond et al., 2002; Nachtsheim et al., 2021). A 
summary of the literature on documented effects of wind farm 
construction on harbor porpoise and harbor seals is described below.
    Brandt et al. (2016) summarized the effects of the construction of 
eight offshore wind projects within the German North Sea (i.e., Alpha 
Ventus, BARD Offshore I, Borkum West II, DanTysk, Global Tech I, 
Meerwind S[uuml]d/Ost, Nordsee Ost, and Riffgat) between 2009 and 2013 
on harbor porpoises, combining PAM data from 2010-2013 and aerial 
surveys from 2009-2013 with data on noise levels associated with pile 
driving. Results of the analysis revealed significant declines in 
porpoise detections during pile driving when compared to 25-48 hours 
before pile driving began, with the magnitude of decline during pile 
driving clearly decreasing with increasing distances to the 
construction site. During the majority of projects, significant 
declines in detections (by at least 20 percent) were found within at 
least 5-10 km of the pile driving site, with declines at up to 20-30 km 
of the pile driving site documented in some cases. Similar results 
demonstrating the long-distance displacement of harbor porpoises (18-25 
km) and harbor seals (up to 40 km) during impact pile driving have also 
been observed during the construction at multiple other European wind 
farms (Tougaard et al., 2009; Bailey et al., 2010; D[auml]hne et al., 
2013; Lucke et al., 2012; Haleters et al., 2015).
    While harbor porpoises and seals tend to move several kilometers 
away from wind farm construction activities, the duration of 
displacement has been documented to be relatively temporary. In two 
studies at Horns Rev II using impact pile driving, harbor porpoise 
returned within 1-2 days following cessation of pile driving (Tougaard 
et al., 2009, Brandt et al., 2011). Similar recovery periods have been 
noted for harbor seals off England during the construction of four wind 
farms (Brasseur et al., 2010; Carroll et al., 2010; Hamre et al., 2011; 
Hastie et al., 2015; Russell et al., 2016). In some cases, an increase 
in harbor porpoise activity has been documented inside wind farm areas 
following construction (e.g., Lindeboom et al., 2011). Other studies 
have noted longer term impacts after impact pile driving. Near Dogger 
Bank in Germany, harbor porpoises continued to avoid the area for over 
2 years after construction began (Gilles et al., 2009). Approximately 
10 years after construction of the Nysted wind farm, harbor porpoise 
abundance had not recovered to the original levels previously seen, 
although the echolocation activity was noted to have been increasing 
when compared to the previous monitoring period (Teilmann and 
Carstensen, 2012). However, overall, there are no indications for a 
population decline of harbor porpoises in European waters (e.g., Brandt 
et al., 2016). Notably, where significant differences in displacement 
and return rates have been identified for these species, the occurrence 
of secondary project-specific influences such as use of mitigation 
measures (e.g., bubble curtains, acoustic deterrent devices (ADDs)) or 
the manner in which species use the habitat in the project area are 
likely the driving factors of this variation.
    NMFS notes the aforementioned studies from Europe involve 
installing much smaller piles than Dominion Energy proposes to install 
and, therefore, we anticipate noise levels from impact pile driving to 
be louder. For this reason, we anticipate that the greater distances of 
displacement observed in harbor porpoise and harbor seals documented in 
Europe are likely to occur off Virginia. However, we do

[[Page 28683]]

not anticipate any greater severity of response due to harbor porpoise 
and harbor seal habitat use off Virginia or population-level 
consequences similar to European findings. In many cases, harbor 
porpoises and harbor seals are resident to the areas where European 
wind farms have been constructed. However, off Virginia, harbor 
porpoises are primarily transient (with higher abundances in winter 
when impact pile driving would not occur) and a very small percentage 
of the large harbor seal population are only seasonally present with no 
rookeries established. In summary, we anticipate that harbor porpoise 
and harbor seals will likely respond to pile driving by moving several 
kilometers away from the source but return to typical habitat use 
patterns when pile driving ceases.
    Some avoidance behavior of other marine mammal species has been 
documented to be dependent on distance from the source. As described 
above, DeRuiter et al. (2013) noted that distance from a sound source 
may moderate marine mammal reactions in their study of Cuvier's beaked 
whales (an acoustically sensitive species), which showed the whales 
swimming rapidly and silently away when a sonar signal was 3.4-9.5 km 
away while showing no such reaction to the same signal when the signal 
was 118 km away even though the received levels were similar. Tyack et 
al. (1983) conducted playback studies of Surveillance Towed Array 
Sensor System (SURTASS) low frequency active (LFA) sonar in a gray 
whale migratory corridor off California. Similar to North Atlantic 
right whales, gray whales migrate close to shore (approximately +2 kms) 
and are low frequency hearing specialists. The LFA sonar source was 
placed within the gray whale migratory corridor (approximately 2 km 
offshore) and offshore of most, but not all, migrating whales 
(approximately 4 km offshore). These locations influenced received 
levels and distance to the source. For the inshore playbacks, not 
unexpectedly, the louder the source level of the playback (i.e., the 
louder the received level), whale avoided the source at greater 
distances. Specifically, when the source level was 170 dB rms and 178 
dB rms, whales avoided the inshore source at ranges of several hundred 
meters, similar to avoidance responses reported by Malme et al. (1983, 
1984). Whales exposed to source levels of 185 dB rms demonstrated 
avoidance levels at ranges of +1 km. Responses to the offshore source 
broadcasting at source levels of 185 and 200 dB, avoidance responses 
were greatly reduced. While there was observed deflection from course, 
in no case did a whale abandon its migratory behavior.
    The signal context of the noise exposure has been shown to play an 
important role in avoidance responses. In a 2007-2008 Bahamas study, 
playback sounds of a potential predator--a killer whale--resulted in a 
similar but more pronounced reaction in beaked whales (an acoustically 
sensitive species), which included longer inter-dive intervals and a 
sustained straight-line departure of more than 20 km from the area 
(Boyd et al., 2008; Southall et al., 2009; Tyack et al., 2011). 
Dominion Energy does not anticipate, and NMFS is not proposing to 
authorize take of beaked whales and, moreover, the sounds produced by 
Dominion Energy do not have signal characteristics similar to 
predators. Therefore we would not expect such extreme reactions to 
occur. Southall et al. 2011 found that blue whales had a different 
response to sonar exposure depending on behavioral state, more 
pronounced when deep feeding/travel modes than when engaged in surface 
feeding.
    One potential consequence of behavioral avoidance is the altered 
energetic expenditure of marine mammals because energy is required to 
move and avoid surface vessels or the sound field associated with 
active sonar (Frid and Dill, 2002). Most animals can avoid that 
energetic cost by swimming away at slow speeds or speeds that minimize 
the cost of transport (Miksis-Olds, 2006), as has been demonstrated in 
Florida manatees (Miksis-Olds, 2006). Those energetic costs increase, 
however, when animals shift from a resting state, which is designed to 
conserve an animal's energy, to an active state that consumes energy 
the animal would have conserved had it not been disturbed. Marine 
mammals that have been disturbed by anthropogenic noise and vessel 
approaches are commonly reported to shift from resting to active 
behavioral states, which would imply that they incur an energy cost.
    Forney et al. (2017) detailed the potential effects of noise on 
marine mammal populations with high site fidelity, including 
displacement and auditory masking, noting that a lack of observed 
response does not imply absence of fitness costs and that apparent 
tolerance of disturbance may have population-level impacts that are 
less obvious and difficult to document. Avoidance of overlap between 
disturbing noise and areas and/or times of particular importance for 
sensitive species may be critical to avoiding population-level impacts 
because (particularly for animals with high site fidelity) there may be 
a strong motivation to remain in the area despite negative impacts. 
Forney et al. (2017) stated that, for these animals, remaining in a 
disturbed area may reflect a lack of alternatives rather than a lack of 
effects.
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, although observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus, 1996; Frid and Dill, 2002). The result of a flight response 
could range from brief, temporary exertion and displacement from the 
area where the signal provokes flight to, in extreme cases, beaked 
whale strandings (Cox et al., 2006; D'Amico et al., 2009). However, it 
should be noted that response to a perceived predator does not 
necessarily invoke flight (Ford and Reeves, 2008), and whether 
individuals are solitary or in groups may influence the response. 
Flight responses of marine mammals have been documented in response to 
mobile high intensity active sonar (e.g., Tyack et al., 2011; DeRuiter 
et al., 2013; Wensveen et al., 2019), and more severe responses have 
been documented when sources are moving towards an animal or when they 
are surprised by unpredictable exposures (Watkins 1986; Falcone et al., 
2017). Generally speaking, however, marine mammals would be expected to 
be less likely to respond with a flight response to either stationery 
pile driving (which they can sense is stationery and predictable) or 
significantly lower-level HRG surveys, unless they are within the area 
ensonified above behavioral harassment thresholds at the moment the 
source is turned on (Watkins, 1986; Falcone et al., 2017).

Diving and Foraging

    Changes in dive behavior in response to noise exposure can vary 
widely. They may consist of increased or decreased dive times and 
surface intervals as well as changes in the rates of ascent and descent 
during a dive (e.g., Frankel and Clark, 2000; Costa et al., 2003; Ng 
and Leung, 2003; Nowacek et al., 2004; Goldbogen et al., 2013a, 2013b). 
Variations in dive behavior may reflect interruptions in biologically 
significant activities (e.g., foraging) or they may be of little 
biological significance. Variations in dive behavior may also

[[Page 28684]]

expose an animal to potentially harmful conditions (e.g., increasing 
the chance of ship-strike) or may serve as an avoidance response that 
enhances survivorship. The impact of a variation in diving resulting 
from an acoustic exposure depends on what the animal is doing at the 
time of the exposure, the type and magnitude of the response, and the 
context within which the response occurs (e.g., the surrounding 
environmental and anthropogenic circumstances).
    Nowacek et al. (2004) reported disruptions of dive behaviors in 
foraging North Atlantic right whales when exposed to an alerting 
stimulus, an action, they noted, that could lead to an increased 
likelihood of ship strike. The alerting stimulus was in the form of an 
18 minute exposure that included three 2-minute signals played three 
times sequentially. This stimulus was designed with the purpose of 
providing signals distinct to background noise that serve as 
localization cues. However, the whales did not respond to playbacks of 
either right whale social sounds or vessel noise, highlighting the 
importance of the sound characteristics in producing a behavioral 
reaction. Although source levels for the proposed pile driving 
activities may exceed the received level of the alerting stimulus 
described by Nowacek et al. (2004), proposed mitigation strategies 
(further described in the Proposed Mitigation section) will reduce the 
severity of response to proposed pile driving activities. Converse to 
the behavior of North Atlantic right whales, Indo-Pacific humpback 
dolphins have been observed to dive for longer periods of time in areas 
where vessels were present and/or approaching (Ng and Leung, 2003). In 
both of these studies, the influence of the sound exposure cannot be 
decoupled from the physical presence of a surface vessel, thus 
complicating interpretations of the relative contribution of each 
stimulus to the response. Indeed, the presence of surface vessels, 
their approach, and speed of approach, seemed to be significant factors 
in the response of the Indo-Pacific humpback dolphins (Ng and Leung, 
2003). Low frequency signals of the Acoustic Thermometry of Ocean 
Climate (ATOC) sound source were not found to affect dive times of 
humpback whales in Hawaiian waters (Frankel and Clark, 2000) or to 
overtly affect elephant seal dives (Costa et al., 2003). They did, 
however, produce subtle effects that varied in direction and degree 
among the individual seals, illustrating the equivocal nature of 
behavioral effects and consequent difficulty in defining and predicting 
them.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the cessation of secondary 
indicators of foraging (e.g., bubble nets or sediment plumes), or 
changes in dive behavior. As for other types of behavioral response, 
the frequency, duration, and temporal pattern of signal presentation, 
as well as differences in species sensitivity, are likely contributing 
factors to differences in response in any given circumstance (e.g., 
Croll et al., 2001; Nowacek et al., 2004; Madsen et al., 2006a; 
Yazvenko et al., 2007; Southall et al., 2019b). An understanding of the 
energetic requirements of the affected individuals and the relationship 
between prey availability, foraging effort and success, and the life 
history stage of the animal can facilitate the assessment of whether 
foraging disruptions are likely to incur fitness consequences 
(Goldbogen et al., 2013; Farmer et al., 2018; Pirotta et al., 2018; 
Southall et al., 2019; Pirotta et al., 2021).
    Impacts on marine mammal foraging rates from noise exposure have 
been documented, though there is little data regarding the impacts of 
offshore turbine construction specifically. Several broader examples 
follow, and it is reasonable to expect that exposure to noise produced 
during the 5-years the proposed rule would be effective could have 
similar impacts.
    Visual tracking, passive acoustic monitoring, and movement 
recording tags were used to quantify sperm whale behavior prior to, 
during, and following exposure to air gun arrays at received levels in 
the range 140-160 dB at distances of 7-13 km, following a phase-in of 
sound intensity and full array exposures at 1-13 km (Madsen et al., 
2006a; Miller et al., 2009). Sperm whales did not exhibit horizontal 
avoidance behavior at the surface. However, foraging behavior may have 
been affected. The sperm whales exhibited 19 percent less vocal (buzz) 
rate during full exposure relative to post exposure, and the whale that 
was approached most closely had an extended resting period and did not 
resume foraging until the air guns had ceased firing. The remaining 
whales continued to execute foraging dives throughout exposure; 
however, swimming movements during foraging dives were six percent 
lower during exposure than control periods (Miller et al., 2009). 
Miller et al. (2009) noted that more data are required to understand 
whether the differences were due to exposure or natural variation in 
sperm whale behavior.
    Balaenopterid whales exposed to moderate low-frequency signals 
similar to the ATOC sound source demonstrated no variation in foraging 
activity (Croll et al., 2001), whereas five out of six North Atlantic 
right whales exposed to an acoustic alarm interrupted their foraging 
dives (Nowacek et al., 2004). Although the received SPLs were similar 
in the latter two studies, the frequency, duration, and temporal 
pattern of signal presentation were different. These factors, as well 
as differences in species sensitivity, are likely contributing factors 
to the differential response. The source levels of both the proposed 
construction and HRG activities exceed the source levels of the signals 
described by Nowacek et al. (2004) and Croll et al. (2001), and noise 
generated by Dominion Energy's activities at least partially overlap in 
frequency with the described signals. Blue whales exposed to mid-
frequency sonar in the Southern California Bight were less likely to 
produce low frequency calls usually associated with feeding behavior 
(Melc[oacute]n et al., 2012). However, Melc[oacute]n et al. (2012) were 
unable to determine if suppression of low frequency calls reflected a 
change in their feeding performance or abandonment of foraging behavior 
and indicated that implications of the documented responses are 
unknown. Further, it is not known whether the lower rates of calling 
actually indicated a reduction in feeding behavior or social contact 
since the study used data from remotely deployed, passive acoustic 
monitoring buoys. Results from the 2010-2011 field season of a 
behavioral response study in Southern California waters indicated that, 
in some cases and at low received levels, tagged blue whales responded 
to mid-frequency sonar but that those responses were mild and there was 
a quick return to their baseline activity (Southall et al., 2011; 
Southall et al., 2012b, Southall et al., 2019b).
    Information on or estimates of the energetic requirements of the 
individuals and the relationship between prey availability, foraging 
effort and success, and the life history stage of the animal will help 
better inform a determination of whether foraging disruptions incur 
fitness consequences. Foraging strategies may impact foraging 
efficiency, such as by reducing foraging effort and increasing success 
in prey detection and capture, in turn promoting fitness and allowing 
individuals to better compensate for foraging disruptions. Surface 
feeding blue whales did not show a change in

[[Page 28685]]

behavior in response to mid-frequency simulated and real sonar sources 
with received levels between 90 and 179 dB re 1 [micro]Pa, but deep 
feeding and non-feeding whales showed temporary reactions including 
cessation of feeding, reduced initiation of deep foraging dives, 
generalized avoidance responses, and changes to dive behavior (DeRuiter 
et al., 2017; Goldbogen et al., 2013b; Sivle et al., 2015). Goldbogen 
et al. (2013b) indicate that disruption of feeding and displacement 
could impact individual fitness and health. However, for this to be 
true, we would have to assume that an individual whale could not 
compensate for this lost feeding opportunity by either immediately 
feeding at another location, by feeding shortly after cessation of 
acoustic exposure, or by feeding at a later time. There is no 
indication that individual fitness and health would be impacted, 
particularly since unconsumed prey would likely still be available in 
the environment in most cases following the cessation of acoustic 
exposure.
    Similarly, while the rates of foraging lunges decrease in humpback 
whales due to sonar exposure, there was variability in the response 
across individuals, with one animal ceasing to forage completely and 
another animal starting to forage during the exposure (Sivle et al., 
2016). In addition, almost half of the animals that demonstrated 
avoidance were foraging before the exposure but the others were not; 
the animals that avoided while not feeding responded at a slightly 
lower received level and greater distance than those that were feeding 
(Wensveen et al., 2017). These findings indicate the behavioral state 
of the animal and foraging strategies play a role in the type and 
severity of a behavioral response. For example, when the prey field was 
mapped and used as a covariate in examining how behavioral state of 
blue whales is influenced by mid-frequency sound, the response in blue 
whale deep-feeding behavior was even more apparent, reinforcing the 
need for contextual variables to be included when assessing behavioral 
responses (Friedlaender et al., 2016).

Vocalizations and Auditory Masking

    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, production of echolocation clicks, calling, 
and singing. Changes in vocalization behavior in response to 
anthropogenic noise can occur for any of these modes and may result 
directly from increased vigilance (also see the Potential Effects of 
Behavioral Disturbance on Marine Mammal Fitness section) or a startle 
response, or from a need to compete with an increase in background 
noise (see Erbe et al., 2016 review on communication masking), the 
latter of which is described more below.
    For example, in the presence of potentially masking signals, 
humpback whales and killer whales have been observed to increase the 
length of their songs (Miller et al., 2000; Fristrup et al., 2003; 
Foote et al., 2004) and blue whales increased song production (Di Iorio 
and Clark, 2009), while North Atlantic right whales have been observed 
to shift the frequency content of their calls upward while reducing the 
rate of calling in areas of increased anthropogenic noise (Parks et 
al., 2007). In some cases, animals may cease or reduce sound production 
during production of aversive signals (Bowles et al., 1994; Thode et 
al., 2020; Cerchio et al., 2014; McDonald et al., 1995). Blackwell et 
al. (2015) showed that whales increased calling rates as soon as air 
gun signals were detectable before ultimately decreasing calling rates 
at higher received levels.
    Sound can disrupt behavior through masking, or interfering with, an 
animal's ability to detect, recognize, or discriminate between acoustic 
signals of interest (e.g., those used for intraspecific communication 
and social interactions, prey detection, predator avoidance, or 
navigation) (Richardson et al., 1995; Erbe and Farmer, 2000; Tyack, 
2000; Erbe et al., 2016). Masking occurs when the receipt of a sound is 
interfered with by another coincident sound at similar frequencies and 
at similar or higher intensity, and may occur whether the sound is 
natural (e.g., snapping shrimp, wind, waves, precipitation) or 
anthropogenic (e.g., shipping, sonar, seismic exploration) in origin. 
The ability of a noise source to mask biologically important sounds 
depends on the characteristics of both the noise source and the signal 
of interest (e.g., signal-to-noise ratio, temporal variability, 
direction), in relation to each other and to an animal's hearing 
abilities (e.g., sensitivity, frequency range, critical ratios, 
frequency discrimination, directional discrimination, age, or TTS 
hearing loss), and existing ambient noise and propagation conditions. 
Masking these acoustic signals can disturb the behavior of individual 
animals, groups of animals, or entire populations. Masking can lead to 
behavioral changes including vocal changes (e.g., Lombard effect, 
increasing amplitude, or changing frequency), cessation of foraging or 
lost foraging opportunities, and leaving an area, to both signalers and 
receivers, in an attempt to compensate for noise levels (Erbe et al., 
2016) or because sounds that would typically have triggered a behavior 
were not detected. In humans, significant masking of tonal signals 
occurs as a result of exposure to noise in a narrow band of similar 
frequencies. As the sound level increases, though, the detection of 
frequencies above those of the masking stimulus decreases also. This 
principle is expected to apply to marine mammals as well because of 
common biomechanical cochlear properties across taxa.
    Therefore, when the coincident (masking) sound is man-made, it may 
be considered harassment when disrupting behavioral patterns. It is 
important to distinguish TTS and PTS, which persist after the sound 
exposure, from masking, which only occurs during the sound exposure. 
Because masking (without resulting in threshold shift) is not 
associated with abnormal physiological function, it is not considered a 
physiological effect, but rather a potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009; Matthews et al., 2016) and may result in energetic 
or other costs as animals change their vocalization behavior (e.g., 
Miller et al., 2000; Foote et al., 2004; Parks et al., 2007; Di Iorio 
and Clark, 2009; Holt et al., 2009). Masking can be reduced in 
situations where the signal and noise come from different directions 
(Richardson et al., 1995), through amplitude modulation of the signal, 
or through other compensatory behaviors (Houser and Moore, 2014). 
Masking can be tested directly in captive species (e.g., Erbe, 2008), 
but in wild populations it must be either modeled or inferred from 
evidence of masking compensation. There are few studies addressing 
real-world masking sounds likely to be experienced by marine mammals in 
the wild (e.g., Branstetter et al., 2013; Cholewiak et al., 2018).
    The echolocation calls of toothed whales are subject to masking by 
high-frequency sound. Human data indicate low-frequency sound can mask 
high-

[[Page 28686]]

frequency sounds (i.e., upward masking). Studies on captive odontocetes 
by Au et al. (1974, 1985, 1993) indicate that some species may use 
various processes to reduce masking effects (e.g., adjustments in 
echolocation call intensity or frequency as a function of background 
noise conditions). There is also evidence that the directional hearing 
abilities of odontocetes are useful in reducing masking at the high-
frequencies these cetaceans use to echolocate, but not at the low-to-
moderate frequencies they use to communicate (Zaitseva et al., 1980). A 
study by Nachtigall and Supin (2008) showed that false killer whales 
adjust their hearing to compensate for ambient sounds and the intensity 
of returning echolocation signals.
    Impacts on signal detection, measured by masked detection 
thresholds, are not the only important factors to address when 
considering the potential effects of masking. As marine mammals use 
sound to recognize conspecifics, prey, predators, or other biologically 
significant sources (Branstetter et al., 2016), it is also important to 
understand the impacts of masked recognition thresholds (often called 
``informational masking''). Branstetter et al. (2016) measured masked 
recognition thresholds for whistle-like sounds of bottlenose dolphins 
and observed that they are approximately 4 dB above detection 
thresholds (energetic masking) for the same signals. Reduced ability to 
recognize a conspecific call or the acoustic signature of a predator 
could have severe negative impacts. Branstetter et al. (2016) observed 
that if ``quality communication'' is set at 90 percent recognition the 
output of communication space models (which are based on 50 percent 
detection) would likely result in a significant decrease in 
communication range.
    As marine mammals use sound to recognize predators (Allen et al., 
2014; Cummings and Thompson, 1971; Cur[eacute] et al., 2015; Fish and 
Vania, 1971), the presence of masking noise may also prevent marine 
mammals from responding to acoustic cues produced by their predators, 
particularly if it occurs in the same frequency band. For example, 
harbor seals that reside in the coastal waters off British Columbia are 
frequently targeted by mammal-eating killer whales. The seals 
acoustically discriminate between the calls of mammal-eating and fish-
eating killer whales (Deecke et al., 2002), a capability that should 
increase survivorship while reducing the energy required to attend to 
all killer whale calls. Similarly, sperm whales (Cur[eacute] et al., 
2016; Isojunno et al., 2016), long-finned pilot whales (Visser et al., 
2016), and humpback whales (Cur[eacute] et al., 2015) changed their 
behavior in response to killer whale vocalization playbacks; these 
findings indicate that some recognition of predator cues could be 
missed if the killer whale vocalizations were masked. The potential 
effects of masked predator acoustic cues depends on the duration of the 
masking noise and the likelihood of a marine mammal encountering a 
predator during the time that detection and recognition of predator 
cues are impeded.
    Redundancy and context can also facilitate detection of weak 
signals. These phenomena may help marine mammals detect weak sounds in 
the presence of natural or manmade noise. Most masking studies in 
marine mammals present the test signal and the masking noise from the 
same direction. The dominant background noise may be highly directional 
if it comes from a particular anthropogenic source such as a ship or 
industrial site. Directional hearing may significantly reduce the 
masking effects of these sounds by improving the effective signal-to-
noise ratio.
    Masking affects both senders and receivers of acoustic signals and, 
at higher levels and longer duration, can potentially have long-term 
chronic effects on marine mammals at the population level as well as at 
the individual level. Low-frequency ambient sound levels have increased 
by as much as 20 dB (more than three times in terms of SPL) in the 
world's ocean from pre-industrial periods, with most of the increase 
from distant commercial shipping (Hildebrand, 2009; Cholewiak et al., 
2018). All anthropogenic sound sources, but especially chronic and 
lower-frequency signals (e.g., from commercial vessel traffic), 
contribute to elevated ambient sound levels, thus intensifying masking.
    In addition to making it more difficult for animals to perceive and 
recognize acoustic cues in their environment, anthropogenic sound 
presents separate challenges for animals that are vocalizing. When they 
vocalize, animals are aware of environmental conditions that affect the 
``active space'' (or communication space) of their vocalizations, which 
is the maximum area within which their vocalizations can be detected 
before it drops to the level of ambient noise (Brenowitz, 2004; Brumm 
et al., 2004; Lohr et al., 2003). Animals are also aware of 
environmental conditions that affect whether listeners can discriminate 
and recognize their vocalizations from other sounds, which is more 
important than simply detecting that a vocalization is occurring 
(Brenowitz, 1982; Brumm et al., 2004; Dooling, 2004; Marten and Marler, 
1977; Patricelli et al., 2006). Most species that vocalize have evolved 
with an ability to make adjustments to their vocalizations to increase 
the signal-to-noise ratio, active space, and recognizability/
distinguishability of their vocalizations in the face of temporary 
changes in background noise (Brumm et al., 2004; Patricelli et al., 
2006). Vocalizing animals can make adjustments to vocalization 
characteristics such as the frequency structure, amplitude, temporal 
structure, and temporal delivery (repetition rate), or ceasing to 
vocalize.
    Many animals will combine several of these strategies to compensate 
for high levels of background noise. Anthropogenic sounds that reduce 
the signal-to-noise ratio of animal vocalizations, increase the masked 
auditory thresholds of animals listening for such vocalizations, or 
reduce the active space of an animal's vocalizations impair 
communication between animals. Most animals that vocalize have evolved 
strategies to compensate for the effects of short-term or temporary 
increases in background or ambient noise on their songs or calls. 
Although the fitness consequences of these vocal adjustments are not 
directly known in all instances, like most other trade-offs animals 
must make, some of these strategies likely come at a cost (Patricelli 
et al., 2006; Noren et al., 2017; Noren et al., 2020). Shifting songs 
and calls to higher frequencies may also impose energetic costs 
(Lambrechts, 1996).
    Marine mammals are also known to make vocal changes in response to 
anthropogenic noise. In cetaceans, vocalization changes have been 
reported from exposure to anthropogenic noise sources such as sonar, 
vessel noise, and seismic surveying (see the following for examples: 
Gordon et al., 2003; Di Iorio and Clark, 2009; Hatch et al., 2012; Holt 
et al., 20098; Holt et al., 2011; Lesage et al., 1999; McDonald et al., 
2009; Parks et al., 2007; Risch et al., 2012; Rolland et al., 2012), as 
well as changes in the natural acoustic environment (Dunlop et al., 
2014). Vocal changes can be temporary, or can be persistent. For 
example, model simulation suggests that the increase in starting 
frequency for the North Atlantic right whale upcall over the last 50 
years resulted in increased detection ranges between right whales. The 
frequency shift, coupled with an increase in call intensity by 20 dB, 
led to a call detectability range of less than 3 km to over 9 km 
(Tennessen and Parks, 2016). Holt et al. (2009) measured killer whale 
call source levels and background noise levels in the one to 40

[[Page 28687]]

kHz band and reported that the whales increased their call source 
levels by one dB SPL for every one dB SPL increase in background noise 
level. Similarly, another study on St. Lawrence River belugas reported 
a similar rate of increase in vocalization activity in response to 
passing vessels (Scheifele et al., 2005). Di Iorio and Clark (2009) 
showed that blue whale calling rates vary in association with seismic 
sparker survey activity, with whales calling more on days with surveys 
than on days without surveys. They suggested that the whales called 
more during seismic survey periods as a way to compensate for the 
elevated noise conditions.
    In some cases, these vocal changes may have fitness consequences, 
such as an increase in metabolic rates and oxygen consumption, as 
observed in bottlenose dolphins when increasing their call amplitude 
(Holt et al., 2015). A switch from vocal communication to physical, 
surface-generated sounds such as pectoral fin slapping or breaching was 
observed for humpback whales in the presence of increasing natural 
background noise levels, indicating that adaptations to masking may 
also move beyond vocal modifications (Dunlop et al., 2010).
    While these changes all represent possible tactics by the sound-
producing animal to reduce the impact of masking, the receiving animal 
can also reduce masking by using active listening strategies such as 
orienting to the sound source, moving to a quieter location, or 
reducing self-noise from hydrodynamic flow by remaining still. The 
temporal structure of noise (e.g., amplitude modulation) may also 
provide a considerable release from masking through comodulation 
masking release (a reduction of masking that occurs when broadband 
noise, with a frequency spectrum wider than an animal's auditory filter 
bandwidth at the frequency of interest, is amplitude modulated) 
(Branstetter and Finneran, 2008; Branstetter et al., 2013). Signal type 
(e.g., whistles, burst-pulse, sonar clicks) and spectral 
characteristics (e.g., frequency modulated with harmonics) may further 
influence masked detection thresholds (Branstetter et al., 2016; 
Cunningham et al., 2014).
    Masking is more likely to occur in the presence of broadband, 
relatively continuous noise sources such as vessels. Several studies 
have shown decreases in marine mammal communication space and changes 
in behavior as a result of the presence of vessel noise. For example, 
right whales were observed to shift the frequency content of their 
calls upward while reducing the rate of calling in areas of increased 
anthropogenic noise (Parks et al., 2007) as well as increasing the 
amplitude (intensity) of their calls (Parks, 2009; Parks et al., 2011). 
Clark et al. (2009) observed that right whales' communication space 
decreased by up to 84 percent in the presence of vessels. Cholewiak et 
al. (2018) also observed loss in communication space in Stellwagen 
National Marine Sanctuary for North Atlantic right whales, fin whales, 
and humpback whales with increased ambient noise and shipping noise. 
Although humpback whales off Australia did not change the frequency or 
duration of their vocalizations in the presence of ship noise, their 
source levels were lower than expected based on source level changes to 
wind noise, potentially indicating some signal masking (Dunlop, 2016). 
Multiple delphinid species have also been shown to increase the minimum 
or maximum frequencies of their whistles in the presence of 
anthropogenic noise and reduced communication space (for examples see: 
Holt et al., 2009; Holt et al., 2011; Gervaise et al., 2012; Williams 
et al., 2013; Hermannsen et al., 2014; Papale et al., 2015; Liu et al., 
2017). While masking impacts are not a concern from lower intensity, 
higher frequency HRG surveys, some degree of masking would be expected 
in the vicinity of turbine pile driving and concentrated support vessel 
operation. However, pile driving is an intermittent sound and would not 
be continuous throughout a day.

Habituation and Sensitization

    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance having a neutral or positive outcome (Bejder et al., 
2009). The opposite process is sensitization, when an unpleasant 
experience leads to subsequent responses, often in the form of 
avoidance, at a lower level of exposure. Both habituation and 
sensitization require an ongoing learning process. As noted, behavioral 
state may affect the type of response. For example, animals that are 
resting may show greater behavioral change in response to disturbing 
sound levels than animals that are highly motivated to remain in an 
area for feeding (Richardson et al., 1995; National Research Council 
(NRC), 2003; Wartzok et al., 2003; Southall et al., 2019b). Controlled 
experiments with captive marine mammals have shown pronounced 
behavioral reactions, including avoidance of loud sound sources (e.g., 
Ridgway et al., 1997; Finneran et al., 2003; Houser et al., 2013a,b; 
Kastelein et al., 2018). Observed responses of wild marine mammals to 
loud impulsive sound sources (typically airguns or acoustic harassment 
devices) have been varied but often consist of avoidance behavior or 
other behavioral changes suggesting discomfort (Morton and Symonds, 
2002; see also Richardson et al., 1995; Nowacek et al., 2007; Tougaard 
et al., 2009; Brandt et al., 2011; Brandt et al., 2012; D[auml]hne et 
al., 2013; Brandt et al., 2014; Russell et al., 2016; Brandt et al., 
2018). Stone (2015a) reported data from at-sea observations during 
1,196 airgun surveys from 1994 to 2010. When large arrays of airguns 
(considered to be 500 in 3 or more) were firing, lateral displacement, 
more localized avoidance, or other changes in behavior were evident for 
most odontocetes. However, significant responses to large arrays were 
found only for the minke whale and fin whale. Behavioral responses 
observed included changes in swimming or surfacing behavior with 
indications that cetaceans remained near the water surface at these 
times. Behavioral observations of gray whales during an air gun survey 
monitored whale movements and respirations pre-, during-, and post-
seismic survey (Gailey et al., 2016). Behavioral state and water depth 
were the best 'natural' predictors of whale movements and respiration 
and after considering natural variation, none of the response variables 
were significantly associated with survey or vessel sounds. Many 
delphinids approach low-frequency airgun source vessels with no 
apparent discomfort or obvious behavioral change (e.g., Barkaszi et 
al., 2012), indicating the importance of frequency output in relation 
to the species' hearing sensitivity.
Physiological Responses
    An animal's perception of a threat may be sufficient to trigger 
stress responses consisting of some combination of behavioral 
responses, autonomic nervous system responses, neuroendocrine 
responses, or immune responses (e.g., Seyle, 1950; Moberg, 2000). In 
many cases, an animal's first and sometimes most economical (in terms 
of energetic costs) response is behavioral avoidance of the potential 
stressor. Autonomic nervous system

[[Page 28688]]

responses to stress typically involve changes in heart rate, blood 
pressure, and gastrointestinal activity. These responses have a 
relatively short duration and may or may not have a significant long-
term effect on an animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha, 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficiently to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker, 2000; 
Romano et al., 2002b) and, more rarely, studied in wild populations 
(e.g., Lusseau and Bejder, 2007; Romano et al., 2002a; Rolland et al., 
2012). For example, Rolland et al. (2012) found that noise reduction 
from reduced ship traffic in the Bay of Fundy was associated with 
decreased stress in North Atlantic right whales.
    These and other studies lead to a reasonable expectation that some 
marine mammals will experience physiological stress responses upon 
exposure to acoustic stressors and that it is possible that some of 
these would be classified as ``distress.'' In addition, any animal 
experiencing TTS would likely also experience stress responses (NRC, 
2003, 2017).
    Respiration naturally varies with different behaviors and 
variations in respiration rate as a function of acoustic exposure can 
be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Mean exhalation rates of gray whales at rest and while 
diving were found to be unaffected by seismic surveys conducted 
adjacent to the whale feeding grounds (Gailey et al., 2007). Studies 
with captive harbor porpoises show increased respiration rates upon 
introduction of acoustic alarms (Kastelein et al., 2001; Kastelein et 
al., 2006a) and emissions for underwater data transmission (Kastelein 
et al., 2005). However, exposure of the same acoustic alarm to a 
striped dolphin under the same conditions did not elicit a response 
(Kastelein et al., 2006a), again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure.

Potential Effects of Disturbance on Marine Mammal Fitness

    The different ways that marine mammals respond to sound are 
sometimes indicators of the ultimate effect that exposure to a given 
stimulus will have on the well-being (survival, reproduction, etc.) of 
an animal. There is little quantitative marine mammal data relating the 
exposure of marine mammals from sound to effects on reproduction or 
survival, though data exists for terrestrial species to which we can 
draw comparisons for marine mammals. Several authors have reported that 
disturbance stimuli may cause animals to abandon nesting and foraging 
sites (Sutherland and Crockford, 1993); may cause animals to increase 
their activity levels and suffer premature deaths or reduced 
reproductive success when their energy expenditures exceed their energy 
budgets (Daan et al., 1996; Feare, 1976; Mullner et al., 2004); or may 
cause animals to experience higher predation rates when they adopt 
risk-prone foraging or migratory strategies (Frid and Dill, 2002). Each 
of these studies addressed the consequences of animals shifting from 
one behavioral state (e.g., resting or foraging) to another behavioral 
state (e.g., avoidance or escape behavior) because of human disturbance 
or disturbance stimuli.
    Attention is the cognitive process of selectively concentrating on 
one aspect of an animal's environment while ignoring other things 
(Posner, 1994). Because animals (including humans) have limited 
cognitive resources, there is a limit to how much sensory information 
they can process at any time. The phenomenon called ``attentional 
capture'' occurs when a stimulus (usually a stimulus that an animal is 
not concentrating on or attending to) ``captures'' an animal's 
attention. This shift in attention can occur consciously or 
subconsciously (for example, when an animal hears sounds that it 
associates with the approach of a predator) and the shift in attention 
can be sudden (Dukas, 2002; van Rij, 2007). Once a stimulus has 
captured an animal's attention, the animal can respond by ignoring the 
stimulus, assuming a ``watch and wait'' posture, or treat the stimulus 
as a disturbance and respond accordingly, which includes scanning for 
the source of the stimulus or ``vigilance'' (Cowlishaw et al., 2004).
    Vigilance is an adaptive behavior that helps animals determine the 
presence or absence of predators, assess their distance from 
conspecifics, or to attend cues from prey (Bednekoff and Lima, 1998; 
Treves, 2000). Despite those benefits, however, vigilance has a cost of 
time; when animals focus their attention on specific environmental 
cues, they are not attending to other activities such as foraging or 
resting. These effects have generally not been demonstrated for marine 
mammals, but studies involving fish and terrestrial animals have shown 
that increased vigilance may substantially reduce feeding rates (Saino, 
1994; Beauchamp and Livoreil, 1997; Fritz et al., 2002; Purser and 
Radford, 2011). Animals will spend more time being vigilant, which may 
translate to less time foraging or resting, when disturbance stimuli 
approach them more directly, remain at closer distances, have a greater 
group size (e.g., multiple surface vessels), or when they co-occur with 
times that an animal perceives increased risk (e.g., when they are 
giving birth or accompanied by a calf).
    The primary mechanism by which increased vigilance and disturbance 
appear to affect the fitness of individual animals is by disrupting an 
animal's time budget and, as a result, reducing the time they might 
spend foraging and resting (which increases an animal's activity rate 
and energy demand while decreasing their caloric intake/energy). In a 
study of northern resident killer

[[Page 28689]]

whales off Vancouver Island, exposure to boat traffic was shown to 
reduce foraging opportunities and increase traveling time (Holt et al., 
2021). A simple bioenergetics model was applied to show that the 
reduced foraging opportunities equated to a decreased energy intake of 
18 percent while the increased traveling incurred an increased energy 
output of 3-4 percent, which suggests that a management action based on 
avoiding interference with foraging might be particularly effective.
    On a related note, many animals perform vital functions, such as 
feeding, resting, traveling, and socializing, on a diel cycle (24-hr 
cycle). Behavioral reactions to noise exposure (such as disruption of 
critical life functions, displacement, or avoidance of important 
habitat) are more likely to be significant for fitness if they last 
more than one diel cycle or recur on subsequent days (Southall et al., 
2007). Consequently, a behavioral response lasting less than one day 
and not recurring on subsequent days is not considered particularly 
severe unless it could directly affect reproduction or survival 
(Southall et al., 2007). It is important to note the difference between 
behavioral reactions lasting or recurring over multiple days and 
anthropogenic activities lasting or recurring over multiple days. For 
example, just because certain activities last for multiple days does 
not necessarily mean that individual animals will be either exposed to 
those activity-related stressors (i.e., sonar) for multiple days or 
further exposed in a manner that would result in sustained multi-day 
substantive behavioral responses. However, special attention is 
warranted where longer-duration activities overlay areas in which 
animals are known to congregate for longer durations for biologically 
important behaviors.
    As noted above, there are few studies that directly illustrate the 
impacts of disturbance on marine mammal populations. Lusseau and Bejder 
(2007) present data from three long-term studies illustrating the 
connections between disturbance from whale-watching boats and 
population-level effects in cetaceans. In Shark Bay, Australia, the 
abundance of bottlenose dolphins was compared within adjacent control 
and tourism sites over three consecutive 4.5-year periods of increasing 
tourism levels. Between the second and third time periods, in which 
tourism doubled, dolphin abundance decreased by 15 percent in the 
tourism area and did not change significantly in the control area. In 
Fiordland, New Zealand, two populations (Milford and Doubtful Sounds) 
of bottlenose dolphins with tourism levels that differed by a factor of 
seven were observed and significant increases in traveling time and 
decreases in resting time were documented for both. Consistent short-
term avoidance strategies were observed in response to tour boats until 
a threshold of disturbance was reached (average 68 minutes between 
interactions), after which the response switched to a longer-term 
habitat displacement strategy. For one population, tourism only 
occurred in a part of the home range. However, tourism occurred 
throughout the home range of the Doubtful Sound population and once 
boat traffic increased beyond the 68-minute threshold (resulting in 
abandonment of their home range/preferred habitat), reproductive 
success drastically decreased (increased stillbirths) and abundance 
decreased significantly (from 67 to 56 individuals in a short period).
    In order to understand how the effects of activities may or may not 
impact species and stocks of marine mammals, it is necessary to 
understand not only what the likely disturbances are going to be but 
how those disturbances may affect the reproductive success and 
survivorship of individuals and then how those impacts to individuals 
translate to population-level effects. Following on the earlier work of 
a committee of the U.S. National Research Council (NRC, 2005), New et 
al. (2014), in an effort termed the Potential Consequences of 
Disturbance (PCoD), outline an updated conceptual model of the 
relationships linking disturbance to changes in behavior and 
physiology, health, vital rates, and population dynamics. This 
framework is a four-step process progressing from changes in individual 
behavior and/or physiology, to changes in individual health, then vital 
rates, and finally to population-level effects. In this framework, 
behavioral and physiological changes can have direct (acute) effects on 
vital rates, such as when changes in habitat use or increased stress 
levels raise the probability of mother-calf separation or predation; 
indirect and long-term (chronic) effects on vital rates, such as when 
changes in time/energy budgets or increased disease susceptibility 
affect health, which then affects vital rates; or no effect to vital 
rates (New et al., 2014). Since this general framework was outlined and 
the relevant supporting literature compiled, multiple studies 
developing state-space energetic models for species with extensive 
long-term monitoring (e.g., southern elephant seals, North Atlantic 
right whales, Ziphiidae beaked whales, and bottlenose dolphins) have 
been conducted and can be used to effectively forecast longer-term, 
population-level impacts from behavioral changes. While these are very 
specific models with very specific data requirements that cannot yet be 
applied broadly to project-specific risk assessments for the majority 
of species, they are a critical first step towards being able to 
quantify the likelihood of a population level effect. Since New et al. 
(2014), several publications have described models developed to examine 
the long-term effects of environmental or anthropogenic disturbance of 
foraging on various life stages of selected species (e.g., sperm whale, 
Farmer et al. (2018); California sea lion, McHuron et al. (2018); blue 
whale, Pirotta et al. (2018a); humpback whale, Dunlop et al. (2021)). 
These models continue to add to refinement of the approaches to the 
PCoD framework. Such models also help identify what data inputs require 
further investigation. Pirotta et al. (2018b) provides a review of the 
PCoD framework with details on each step of the process and approaches 
to applying real data or simulations to achieve each step.
    Despite its simplicity, there are few complete PCoD models 
available for any marine mammal species due to a lack of data available 
to parameterize many of the steps. To date, no PCoD model has been 
fully parameterized with empirical data (Pirotta et al., 2018a) due to 
the fact they are data intensive and logistically challenging to 
complete. Therefore, most complete PCoD models include simulations, 
theoretical modeling, and expert opinion to move through the steps. For 
example, PCoD models have been developed to evaluate the effect of wind 
farm construction on the North Sea harbor porpoise populations (e.g., 
King et al., 2015; Nabe-Nielsen et al., 2018). These models include a 
mix of empirical data, expert elicitation (King et al., 2015) and 
simulations of animals' movements, energetics, and/or survival (New et 
al., 2014; Nabe-Nielsen et al., 2018).
    PCoD models may also be approached in different manners. Dunlop et 
al. (2021) modeled migrating humpback whale mother-calf pairs in 
response to seismic surveys using both a forwards and backwards 
approach. While a typical forwards approach can determine if a stressor 
would have population-level consequences, Dunlop et al. demonstrated 
that working backwards through a PCoD model can be used to assess the 
``worst case'' scenario for an interaction of a target species and 
stressor. This method may

[[Page 28690]]

be useful for future management goals when appropriate data becomes 
available to fully support the model. In another example, harbor 
porpoise PCoD model investigating the impact of seismic surveys on 
harbor porpoise included an investigation on underlying drivers of 
vulnerability. Harbor porpoise movement and foraging were modeled for 
baseline periods and then for periods with seismic surveys as well; the 
models demonstrated that temporal (i.e., seasonal) variation in 
individual energetics and their link to costs associated with 
disturbances was key in predicting population impacts (Gallagher et 
al., 2021).
    Behavioral change, such as disturbance manifesting in lost foraging 
time, in response to anthropogenic activities is often assumed to 
indicate a biologically significant effect on a population of concern. 
However, as described above, individuals may be able to compensate for 
some types and degrees of shifts in behavior, preserving their health 
and thus their vital rates and population dynamics. For example, New et 
al. (2013) developed a model simulating the complex social, spatial, 
behavioral and motivational interactions of coastal bottlenose dolphins 
in the Moray Firth, Scotland, to assess the biological significance of 
increased rate of behavioral disruptions caused by vessel traffic. 
Despite a modeled scenario in which vessel traffic increased from 70 to 
470 vessels a year (a six-fold increase in vessel traffic) in response 
to the construction of a proposed offshore renewables' facility, the 
dolphins' behavioral time budget, spatial distribution, motivations, 
and social structure remain unchanged. Similarly, two bottlenose 
dolphin populations in Australia were also modeled over five years 
against a number of disturbances (Reed et al., 2020), and results 
indicated that habitat/noise disturbance had little overall impact on 
population abundances in either location, even in the most extreme 
impact scenarios modeled. By integrating different sources of data 
(e.g., controlled exposure data, activity monitoring, telemetry 
tracking, and prey sampling) into a theoretical model to predict 
effects from sonar on a blue whale's daily energy intake, Pirotta et 
al. (2021) found that tagged blue whales' activity budgets, lunging 
rates, and ranging patterns caused variability in their predicted cost 
of disturbance. This method may be useful for future management goals 
when appropriate data becomes available to fully support the model. 
Harbor porpoise movement and foraging were modeled for baseline periods 
and then for periods with seismic surveys as well; the models 
demonstrated that the seasonality of the seismic activity was an 
important predictor of impact (Gallagher et al., 2021).
    Nearly all PCoD studies and experts agree that infrequent exposures 
of a single day or less are unlikely to impact individual fitness, let 
alone lead to population level effects (Booth et al., 2016; Booth et 
al., 2017; Christiansen and Lusseau, 2015; Farmer et al., 2018; Wilson 
et al., 2020; Harwood and Booth, 2016; King et al., 2015; McHuron et 
al., 2018; National Academies of Sciences, Engineering, and Medicine 
(NAS), 2017; New et al., 2014; Pirotta et al., 2018; Southall et al., 
2007; Villegas-Amtmann et al., 2015). As described through this 
proposed rule, NMFS expects that any behavioral disturbance that would 
occur due to animals being exposed to construction activity would be of 
a relatively short duration, with behavior returning to a baseline 
state shortly after the acoustic stimuli ceases or the animal moves far 
enough away from the source. Given this, and NMFS' evaluation of the 
available PCoD studies, and the required mitigation discussed later, 
any such behavioral disturbance resulting from Dominion Energy's 
activities is not expected to impact individual animals' health or have 
effects on individual animals' survival or reproduction, thus no 
detrimental impacts at the population level are anticipated. Marine 
mammals may temporarily avoid the immediate area but are not expected 
to permanently abandon the area or their migratory or foraging 
behavior. Impacts to breeding, feeding, sheltering, resting, or 
migration are not expected nor are shifts in habitat use, distribution, 
or foraging success.

Potential Effects of Vessel Strike on Marine Mammals

    Vessel collisions with marine mammals, also referred to as vessel 
strikes or ship strikes, can result in death or serious injury of the 
animal. Wounds resulting from ship strike may include massive trauma, 
hemorrhaging, broken bones, or propeller lacerations (Knowlton and 
Kraus, 2001). An animal at the surface could be struck directly by a 
vessel, a surfacing animal could hit the bottom of a vessel, or an 
animal just below the surface could be cut by a vessel's propeller. 
Superficial strikes may not kill or result in the death of the animal. 
Lethal interactions are typically associated with large whales, which 
are occasionally found draped across the bulbous bow of large 
commercial ships upon arrival in port. Although smaller cetaceans are 
more maneuverable in relation to large vessels than are large whales, 
they may also be susceptible to strike. The severity of injuries 
typically depends on the size and speed of the vessel (Knowlton and 
Kraus, 2001; Laist et al., 2001; Vanderlaan and Taggart, 2007; Conn and 
Silber, 2013). Impact forces increase with speed as does the 
probability of a strike at a given distance (Silber et al., 2010; Gende 
et al., 2011).
    The most vulnerable marine mammals are those that spend extended 
periods of time at the surface in order to restore oxygen levels within 
their tissues after deep dives (e.g., the sperm whale). In addition, 
some baleen whales seem generally unresponsive to vessel sound, making 
them more susceptible to vessel collisions (Nowacek et al., 2004). 
These species are primarily large, slow moving whales. Marine mammal 
responses to vessels may include avoidance and changes in dive pattern 
(NRC, 2003).
    An examination of all known ship strikes from all shipping sources 
(civilian and military) indicates vessel speed is a principal factor in 
whether a vessel strike occurs and, if so, whether it results in 
injury, serious injury, or mortality (Knowlton and Kraus, 2001; Laist 
et al., 2001; Jensen and Silber, 2003; Pace and Silber, 2005; 
Vanderlaan and Taggart, 2007; Conn and Silber, 2013). In assessing 
records in which vessel speed was known, Laist et al. (2001) found a 
direct relationship between the occurrence of a whale strike and the 
speed of the vessel involved in the collision. The authors concluded 
that most deaths occurred when a vessel was traveling in excess of 13 
kts.
    Jensen and Silber (2003) detailed 292 records of known or probable 
ship strikes of all large whale species from 1975 to 2002. Of these, 
vessel speed at the time of collision was reported for 58 cases. Of 
these 58 cases, 39 (or 67 percent) resulted in serious injury or death 
(19 of those resulted in serious injury as determined by blood in the 
water, propeller gashes or severed tailstock, and fractured skull, jaw, 
vertebrae, hemorrhaging, massive bruising or other injuries noted 
during necropsy and 20 resulted in death). Operating speeds of vessels 
that struck various species of large whales ranged from 2 to 51 kn. The 
majority (79 percent) of these strikes occurred at speeds of 13 kn or 
greater. The average speed that resulted in serious injury or death was 
18.6 kn. Pace and Silber (2005) found that the probability of death or 
serious injury increased rapidly with increasing vessel speed. 
Specifically, the predicted probability of serious injury or death 
increased from 45 to 75 percent as vessel speed

[[Page 28691]]

increased from 10 to 14 kn, and exceeded 90 percent at 17 kn. Higher 
speeds during collisions result in greater force of impact and also 
appear to increase the chance of severe injuries or death. While 
modeling studies have suggested that hydrodynamic forces pulling whales 
toward the vessel hull increase with increasing speed (Knowlton et al., 
1995; Clyne, 1999), this is inconsistent with Silber et al. (2010), 
which demonstrated that there is no such relationship (i.e., 
hydrodynamic forces are independent of speed).
    In a separate study, Vanderlaan and Taggart (2007) analyzed the 
probability of lethal mortality of large whales at a given speed, 
showing that the greatest rate of change in the probability of a lethal 
injury to a large whale as a function of vessel speed occurs between 
8.6 and 15 kn. The chances of a lethal injury decline from 
approximately 80 percent at 15 kn to approximately 20 percent at 8.6 
kn. At speeds below 11.8 kn, the chances of lethal injury drop below 50 
percent, while the probability asymptotically increases toward 100 
percent above 15 kn.
    The Jensen and Silber (2003) report notes that the Large Whale Ship 
Strike Database represents a minimum number of collisions because the 
vast majority probably goes undetected or unreported. In contrast, 
Dominion Energy's personnel are likely to detect any strike that does 
occur because of the required personnel training and lookouts, along 
with the inclusion of Protected Species Observers (as described in the 
Proposed Mitigation section), and they are required to report all ship 
strikes involving marine mammals.
    In the CVOW-C project area, NMFS has no documented vessel strikes 
of marine mammals by Dominion Energy during previous site 
characterization surveys. Given the comprehensive mitigation and 
monitoring measures (see the Proposed Mitigation and Proposed 
Monitoring and Reporting section) that would be required of Dominion 
Energy, NMFS believes that a vessel strike is not likely to occur.

Potential Effects to Marine Mammal Habitat

    Dominion Energy's proposed construction activities could 
potentially affect marine mammal habitat through the introduction of 
impacts to the prey species of marine mammals (through noise, 
oceanographic processes, or reef effects), acoustic habitat (sound in 
the water column), water quality, and biologically important habitat 
for marine mammals.
Effects on Marine Mammal Prey
    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species (e.g., crustaceans, 
cephalopods, fish, and zooplankton). Marine mammal prey varies by 
species, season, and location and, for some, is not well documented. 
Here, we describe studies regarding the effects of noise on known 
marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009). 
The most likely effects on fishes exposed to loud, intermittent, low-
frequency sounds are behavioral responses (i.e., flight or avoidance). 
Short duration, sharp sounds (such as pile driving or air guns) can 
cause overt or subtle changes in fish behavior and local distribution. 
The reaction of fish to acoustic sources depends on the physiological 
state of the fish, past exposures, motivation (e.g., feeding, spawning, 
migration), and other environmental factors. Key impacts to fishes may 
include behavioral responses, hearing damage, barotrauma (pressure-
related injuries), and mortality. While it is clear that the behavioral 
responses of individual prey, such as displacement or other changes in 
distribution, can have direct impacts on the foraging success of marine 
mammals, the effects on marine mammals of individual prey that 
experience hearing damage, barotrauma, or mortality is less clear, 
though obviously population scale impacts that meaningfully reduce the 
amount of prey available could have more serious impacts.
    Fishes, like other vertebrates, have a variety of different sensory 
systems to glean information from the ocean around them (Hawkins and 
Johnstone, 1978; Astrup and Mohl, 1993; Astrup, 1999; Popper et al., 
2003; Ladich and Popper, 2004; Nedwell et al., 2004; Popper et al., 
2005; Braun and Grande, 2008; Ladich and Schulz-Mirbach, 2016; Mann, 
2016; Carroll et al., 2017). Depending on their hearing anatomy and 
peripheral sensory structures, which vary among species, fishes hear 
sounds using pressure and particle motion sensitivity capabilities and 
detect the motion of surrounding water (Fay et al., 2008). Most marine 
fishes primarily detect particle motion using the inner ear and lateral 
line system while some fishes possess additional morphological 
adaptations or specializations that can enhance their sensitivity to 
sound pressure, such as a gas-filled swim bladder (Braun and Grande, 
2008; Popper and Fay, 2011).
    Hearing capabilities vary considerably between different fish 
species with data only available for just over 100 species out of the 
34,000 marine and freshwater fish species (Eschmeyer and Fong, 2016). 
In order to better understand acoustic impacts on fishes, fish hearing 
groups are defined by species that possess a similar continuum of 
anatomical features, which result in varying degrees of hearing 
sensitivity (Popper and Hastings, 2009a). There are four hearing groups 
defined for all fish species (modified from Popper et al., 2014) within 
this analysis, and they include: fishes without a swim bladder (e.g., 
flatfish, sharks, rays, etc.); fishes with a swim bladder not involved 
in hearing (e.g., salmon, cod, pollock, etc.); fishes with a swim 
bladder involved in hearing (e.g., sardines, anchovy, herring, etc.); 
and fishes with a swim bladder involved in hearing and high-frequency 
hearing (e.g., shad and menhaden). Most marine mammal fish prey species 
would not be likely to perceive or hear mid- or high-frequency sonars. 
While hearing studies have not been done on sardines and northern 
anchovies, it would not be unexpected for them to have hearing 
similarities to Pacific herring (up to 2-5 kHz) (Mann et al., 2005). 
Currently, less data are available to estimate the range of best 
sensitivity for fishes without a swim bladder.
    In terms of physiology, multiple scientific studies have documented 
a lack of mortality or physiological effects to fish from exposure to 
low- and mid-frequency sonar and other sounds (J[oslash]rgensen et al., 
2005; Kvadsheim and Sevaldsen, 2005; Popper et al., 2007; Kane et al., 
2010; Halvorsen et al., 2012; Watwood et al., 2016; Juanes et al., 
2017; Popper et al., 2016). Techer et al. (2017) exposed carp in 
floating cages for up to 30 days to low-power 23 and 46 kHz source 
without any significant physiological response. Other studies have 
documented either a lack of TTS in species whose hearing range cannot 
perceive sonar (such as Navy sonar), or for those species that could 
perceive sonar-like signals, any TTS experienced would be recoverable 
(Popper and Hastings, 2009a, 2009b; Halvorsen et al., 2012; Ladich and 
Fay, 2013; Popper et al., 2014; Smith, 2016). Only fishes that have 
specializations that enable them to hear sounds above about 2,500 Hz 
(2.5 kHz) such as herring (Mann et al., 2005; Halvorsen et al., 2012; 
Popper et al., 2014; Mann, 2016) would have the potential to receive 
TTS or exhibit behavioral responses from exposure to mid-frequency 
sonar. In addition, any sonar induced TTS to fish whose

[[Page 28692]]

hearing range could perceive sonar would only occur in the narrow 
spectrum of the source (e.g., 3.5 kHz) compared to the fish's total 
hearing range (e.g., 0.01 kHz to 5 kHz).
    In terms of behavioral responses, Juanes et al. (2017) discuss the 
potential for negative impacts from anthropogenic noise on fish, but 
the author's focus was on broader based sounds, such as ship and boat 
noise sources. Watwood et al. (2016) also documented no behavioral 
responses by reef fish after exposure to mid-frequency active sonar. 
Doksaeter et al. (2009; 2012) reported no behavioral responses to mid-
frequency sonar (such as naval sonar) by Atlantic herring; 
specifically, no escape reactions (vertically or horizontally) were 
observed in free swimming herring exposed to mid-frequency sonar 
transmissions. Based on the results by Doksaeter et al. (2009), 
Doksaeter et al. (2012), and Sivle et al. (2012), Sivle et al. (2014) 
created a model in order to report on the possible population-level 
effects on Atlantic herring from active sonar. The authors concluded 
that the use of sonar poses little risk to populations of herring 
regardless of season, even when the herring populations are aggregated 
and directly exposed to sonar. Finally, Bruintjes et al. (2016) 
commented that fish exposed to any short-term noise within their 
hearing range might initially startle, but would quickly return to 
normal behavior.
    Pile-driving noise during construction is of particular concern as 
the very high sound pressure levels could potentially prevent fish from 
reaching breeding or spawning sites, finding food, and acoustically 
locating mates. A playback study in West Scotland revealed that there 
was a significant movement response to the pile-driving stimulus in 
both species at relatively low received sound pressure levels (sole: 
144-156 dB re 1[mu]Pa Peak; cod: 140-161 dB re 1 [mu]Pa Peak, particle 
motion between 6.51 x 10\3\ and 8.62 x 10\4\ m/s\2\ peak) (Mueller-
Blenkle et al., 2010). The swimming speed of sole increased 
significantly during the playback of construction noise when compared 
to the playbacks of before and after construction. While not 
statistically significant, cod also displayed a similar behavioral 
response during before, during, and after construction playbacks. 
However, cod demonstrated a specific and significant freezing response 
at the onset and cessation of the playback recording. In both species, 
indications were present displaying directional movements away from the 
playback source. During wind farm construction in the Eastern Taiwan 
Strait, Type 1 soniferous fish chorusing showed a relatively lower 
intensity and longer duration while Type 2 chorusing exhibited higher 
intensity and no changes in its duration. Deviation from regular fish 
vocalization patterns may affect fish reproductive success, cause 
migration, augmented predation, or physiological alterations.
    Occasional behavioral reactions to activities that produce 
underwater noise sources are unlikely to cause long-term consequences 
for individual fish or populations. The most likely impact to fish from 
impact and vibratory pile driving activities at the project areas would 
be temporary behavioral avoidance of the area. Any behavioral avoidance 
by fish of the disturbed area would still leave significantly large 
areas of fish and marine mammal foraging habitat in the nearby 
vicinity. The duration of fish avoidance of an area after pile driving 
stops is unknown, but a rapid return to normal recruitment, 
distribution and behavior is anticipated. In general, any behavioral 
impacts to prey species are expected to be minor, temporary, and 
localized given the relatively small areas being affected and the short 
duration of individual pile driving events.
    SPLs of sufficient strength have been known to cause fish auditory 
impairment, injury and mortality. Popper et al. (2014) found that fish 
with or without air bladders could experience TTS at 186 dB 
SELcum. Mortality could occur for fish without swim bladders 
at >216 dB SELcum. Those with swim bladders or at the egg or 
larvae life stage, mortality was possible at >203 dB SELcum. 
Other studies found that 203 dB SELcum or above caused a 
physiological response in other fish species (Casper et al., 2012, 
Halvorsen et al., 2012a, Halvorsen et al., 2012b, Casper et al., 2013a, 
Casper et al., 2013b). However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours 
for one species. Impacts would be most severe when the individual fish 
is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death, and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al., 2012b; Casper et al., 2013). As described in 
the Proposed Mitigation section below, Dominion Energy would utilize a 
sound attenuation device which would reduce potential for injury to 
marine mammal prey. Other fish that experience hearing loss as a result 
of exposure to impulsive sound sources may have a reduced ability to 
detect relevant sounds such as predators, prey, or social 
vocalizations. However, PTS has not been known to occur in fishes and 
any hearing loss in fish may be as temporary as the timeframe required 
to repair or replace the sensory cells that were damaged or destroyed 
(Popper et al., 2005; Popper et al., 2014; Smith et al., 2006). It is 
not known if damage to auditory nerve fibers could occur, and if so, 
whether fibers would recover during this process.
    Required soft-starts would allow prey and marine mammals to move 
away from the source prior to any noise levels that may physically 
injure prey and the use of the noise attenuation devices would reduce 
noise levels to the degree any mortality or injury of prey is also 
minimized. Use of bubble curtains, in addition to reducing impacts to 
marine mammals, for example, is a key mitigation measure in reducing 
injury and mortality of marine mammal prey. However, we recognize some 
mortality, physical injury and hearing impairment in marine mammal prey 
may occur but we anticipate the amount of prey impacted in this manner 
is minimal compared to overall availability. Any behavioral responses 
to pile driving by marine mammal prey are expected to be relatively 
brief. We expect that other impacts such as stress or masking would 
occur in fish that serve as marine mammals prey (Popper et al., 2019); 
however, those impacts would be limited to the duration of impact pile 
driving if prey were to move out the area in response to noise, these 
impacts would be minimized.
    In addition to fish, prey sources such as marine invertebrates 
could potentially be impacted by noise stressors as a result of the 
proposed activities. However, most marine invertebrates' ability to 
sense sounds is limited. Invertebrates appear to be able to detect 
sounds (Pumphrey, 1950; Frings and Frings, 1967) and are most sensitive 
to low-frequency sounds (Packard et al., 1990; Budelmann and 
Williamson, 1994; Lovell et al., 2005; Mooney et al., 2010). Data on 
response of invertebrates such as squid, another marine mammal prey 
species, to anthropogenic sound is more limited (de Soto, 2016; Sole et 
al., 2017b). Data suggest that cephalopods are capable of sensing the 
particle motion of sounds and detect low frequencies up to 1-1.5 kHz, 
depending on the species, and so are likely to detect air gun noise 
(Kaifu et al., 2008; Hu et al., 2009; Mooney et

[[Page 28693]]

al., 2010; Samson et al., 2014). Sole et al. (2017) reported 
physiological injuries to cuttlefish in cages placed at-sea when 
exposed during a controlled exposure experiment to low-frequency 
sources (315 Hz, 139 to 142 dB re 1 [mu]Pa\2\ and 400 Hz, 139 to 141 dB 
re 1 [mu]Pa\2\). Fewtrell and McCauley (2012) reported squids 
maintained in cages displayed startle responses and behavioral changes 
when exposed to seismic air gun sonar (136-162 re 1 
[mu]Pa\2\[middot]s). Jones et al. (2020) found that when squid 
(Doryteuthis pealeii) were exposed to impulse pile driving noise, body 
pattern changes, inking, jetting, and startle responses were observed 
and nearly all squid exhibited at least one response. However, these 
responses occurred primarily during the first eight impulses and 
diminished quickly, indicating potential rapid, short-term habituation. 
Packard et al. (1990) showed that cephalopods were sensitive to 
particle motion, not sound pressure, and Mooney et al. (2010) 
demonstrated that squid statocysts (specialized sensory organ inside 
the head called a statocyst that may help an animal determine its 
position in space (orientation) and maintain balance) act as an 
accelerometer through which particle motion of the sound field can be 
detected (Budelmann, 1992). Auditory injuries (lesions occurring on the 
statocyst sensory hair cells) have been reported upon controlled 
exposure to low-frequency sounds, suggesting that cephalopods are 
particularly sensitive to low-frequency sound (Andre et al., 2011; Sole 
et al., 2013). Behavioral responses, such as inking and jetting, have 
also been reported upon exposure to low-frequency sound (McCauley et 
al., 2000b; Samson et al., 2014). Squids, like most fish species, are 
likely more sensitive to low frequency sounds, and may not perceive 
mid- and high-frequency sonars.
    With regard to potential impacts on zooplankton, McCauley et al. 
(2017) found that exposure to airgun noise resulted in significant 
depletion for more than half the taxa present and that there were two 
to three times more dead zooplankton after airgun exposure compared 
with controls for all taxa, within 1 km of the airguns. However, the 
authors also stated that in order to have significant impacts on r-
selected species (i.e., those with high growth rates and that produce 
many offspring) such as plankton, the spatial or temporal scale of 
impact must be large in comparison with the ecosystem concerned, and it 
is possible that the findings reflect avoidance by zooplankton rather 
than mortality (McCauley et al., 2017). In addition, the results of 
this study are inconsistent with a large body of research that 
generally finds limited spatial and temporal impacts to zooplankton as 
a result of exposure to airgun noise (e.g., Dalen and Knutsen, 1987; 
Payne, 2004; Stanley et al., 2011). Most prior research on this topic, 
which has focused on relatively small spatial scales, has showed 
minimal effects (e.g., Kostyuchenko, 1973; Booman et al., 1996; 
S[aelig]tre and Ona, 1996; Pearson et al., 1994; Bolle et al., 2012).
    A modeling exercise was conducted as a follow-up to the McCauley et 
al. (2017) study (as recommended by McCauley et al.), in order to 
assess the potential for impacts on ocean ecosystem dynamics and 
zooplankton population dynamics (Richardson et al., 2017). Richardson 
et al. (2017) found that a full-scale airgun survey would impact 
copepod abundance within the survey area, but that effects at a 
regional scale were minimal (2 percent decline in abundance within 150 
km of the survey area and effects not discernible over the full 
region). The authors also found that recovery within the survey area 
would be relatively quick (3 days following survey completion), and 
suggest that the quick recovery was due to the fast growth rates of 
zooplankton, and the dispersal and mixing of zooplankton from both 
inside and outside of the impacted region. The authors also suggest 
that surveys in areas with more dynamic ocean circulation in comparison 
with the study region and/or with deeper waters (i.e., typical offshore 
wind locations) would have less net impact on zooplankton.
    Notably, a recently described study produced results inconsistent 
with those of McCauley et al. (2017). Researchers conducted a field and 
laboratory study to assess if exposure to airgun noise affects 
mortality, predator escape response, or gene expression of the copepod 
Calanus finmarchicus (Fields et al., 2019). Immediate mortality of 
copepods was significantly higher, relative to controls, at distances 
of 5 m or less from the airguns. Mortality one week after the airgun 
blast was significantly higher in the copepods placed 10 m from the 
airgun but was not significantly different from the controls at a 
distance of 20 m from the airgun. The increase in mortality, relative 
to controls, did not exceed 30 percent at any distance from the airgun. 
Moreover, the authors caution that even this higher mortality in the 
immediate vicinity of the airguns may be more pronounced than what 
would be observed in free-swimming animals due to increased flow speed 
of fluid inside bags containing the experimental animals. There were no 
sub-lethal effects on the escape performance or the sensory threshold 
needed to initiate an escape response at any of the distances from the 
airgun that were tested. Whereas McCauley et al. (2017) reported an SEL 
of 156 dB at a range of 509-658 m, with zooplankton mortality observed 
at that range, Fields et al. (2019) reported an SEL of 186 dB at a 
range of 25 m, with no reported mortality at that distance.
    The presence of large numbers of turbines has been shown to impact 
meso- and sub-meso-scale water column circulation, which can affect the 
density, distribution, and energy content of zooplankton and thereby, 
their availability as marine mammal prey. The presence and operation of 
structures such as wind turbines are, in general, likely to result in 
local and broader oceanographic effects in the marine environment and 
may disrupt marine mammal prey, such as dense aggregations and 
distribution of zooplankton, through altering the strength of tidal 
currents and associated fronts, changes in stratification, primary 
production, the degree of mixing, and stratification in the water 
column (Chen et al., 2021, Johnson et al., 2021, Christiansen et al., 
2022, Dorrell et al., 2022). However, the scale of impacts is difficult 
to predict and may vary from meters to hundreds of meters for local 
individual turbine impacts (Schultze et al., 2020) to large-scale 
dipoles of surface elevation changes stretching hundreds of kilometers 
(Christiansen et al., 2022).
    Dominion Energy anticipates that some turbines would become 
operational as early as 2025 with all 176 turbines being operational by 
the end of 2027. As described above, there is scientific uncertainty 
around the scale of oceanographic impacts (meters to kilometers) 
associated with turbine operation. CVOW-C is located offshore of 
Virginia along the Mid-Atlantic Bight. The transition zone between the 
Mid-Atlantic Bight and South Atlantic Bight is located just south of 
the project area, off Cape Hatteras, North Carolina. This zone provides 
the project area with larval ichthyoplankton flow via prevailing 
currents. However, the project area does not include key foraging 
grounds for marine mammals with planktonic diets (e.g., North Atlantic 
right whale) as all known prime foraging habitat is located much 
further north, off southern New England and north into Canada. This 
foraging area is approximately 630 km north of the project area, and it 
would be highly unlikely for this foraging area to be

[[Page 28694]]

influenced by activities related to the CVOW-C proposed project.
    Although the project area does not provide high-quality foraging 
habitat for plankton-feeding marine mammals, such as North Atlantic 
right whales, coastal Virginia provides seasonal high-quality foraging 
habitat for piscivorous marine mammals, such as humpback whales. 
Generally speaking and depending on the extent, impacts on prey could 
impact the distribution of marine mammals in an area, potentially 
necessitating additional energy expenditure to find and capture prey. 
However, at the temporal and spatial scales anticipated for this 
activity, any such impacts on prey are not expected to impact the 
reproduction or survival of any individual marine mammals. Although 
studies assessing the impacts of offshore wind development on marine 
mammals are limited, the repopulation of wind energy areas by harbor 
porpoises (Brandt et al., 2016; Lindeboom et al., 2011) and harbor 
seals (Lindeboom et al., 2011; Russell et al., 2016) following the 
installation of wind turbines is promising. Overall, any impacts to 
marine mammal foraging capabilities due to effects on prey aggregation 
from the turbine presence and operation at the CVOW-C project during 
the effective period of the proposed rule are likely to be limited and 
areas known to support North Atlantic right whale migration would not 
be affected by the operation of the CVOW-C project.
    In general, impacts to marine mammal prey species are primarily 
expected to be relatively minor and temporary due to the relatively 
small areas being affected compared to available habitat and the 
duration of individual pile driving activities. Some mortality of prey 
inside the bubble curtain may occur; however, this would be very 
limited. NMFS does not expect HRG acoustic sources to impact fish and 
most sources are likely outside the hearing range of the primary prey 
species in the project area.
    Overall, the combined impacts of sound exposure and oceanographic 
impacts on marine mammal habitat resulting from the proposed activities 
would not be expected to have measurable effects on populations of 
marine mammal prey species. Prey species exposed to sound might move 
away from the sound source, experience TTS, experience masking of 
biologically relevant sounds, or show no obvious direct effects; 
however, for Dominion Energy's activity, as described above, these 
impacts would not be expected to impact marine mammal foraging in a 
manner that would affect marine mammal reproduction or survival.
Acoustic Habitat
    Acoustic habitat is the soundscape, which encompasses all of the 
sound present in a particular location and time, as a whole when 
considered from the perspective of the animals experiencing it. Animals 
produce sound for, or listen for sounds produced by, conspecifics 
(communication during feeding, mating, and other social activities), 
other animals (finding prey or avoiding predators), and the physical 
environment (finding suitable habitats, navigating). Soundscapes are 
also defined by, and acoustic habitat influenced by, the total 
contribution of anthropogenic sound. This may include incidental 
emissions from sources such as vessel traffic or may be intentionally 
introduced to the marine environment for data acquisition purposes (as 
in the use of air gun arrays) or for Navy training and testing purposes 
(as in the use of sonar and explosives and other acoustic sources). 
Together, sounds made by animals, generated by the geophysical 
environment (e.g., produced by earthquakes, lightning, wind, rain, 
waves), or contributed from man-made sources, make up the natural 
contributions to the total acoustics of a place. These acoustic 
conditions, termed acoustic habitat, are one attribute of an animal's 
total habitat.
    Anthropogenic noise varies widely in its frequency, content, 
duration, and loudness and these characteristics greatly influence the 
potential habitat-mediated effects to marine mammals (please also see 
the previous discussion on Masking), which may range from local effects 
for brief periods of time to chronic effects over large areas and for 
long durations. Depending on the extent of effects to habitat, animals 
may alter their communications signals (thereby potentially expending 
additional energy) or miss acoustic cues (either conspecific or 
adventitious). Problems arising from a failure to detect cues are more 
likely to occur when noise stimuli are chronic (e.g., longer duration 
and spread over larger areas) and overlap with biologically relevant 
cues used for communication, orientation, and predator/prey detection 
(Francis and Barber, 2013). For more detail on these concepts, e.g., 
Barber et al., 2009; Pijanowski et al., 2011; Francis and Barber, 2013; 
Lillis et al., 2014.
    The term ``listening area'' refers to the region of ocean over 
which sources of sound of any kind can be detected by an animal at the 
center of the space. Loss of ``communication space'' concerns the area 
over which a specific animal signal, used to communicate with 
conspecifics in biologically important contexts (e.g., foraging, 
mating), can be heard, in noisier relative to quieter conditions (Clark 
et al., 2009). Lost listening area concerns the more generalized 
contraction of the range over which animals would be able to detect a 
variety of signals of biological importance, including eavesdropping on 
predators and prey (Barber et al., 2009). Such metrics do not, in and 
of themselves, document fitness consequences for the marine animals 
that live in chronically noisy environments. Long-term population-level 
consequences mediated through changes in the ultimate survival and 
reproductive success of individuals are difficult to study, and 
particularly so underwater. However, it is increasingly well documented 
that aquatic species rely on qualities of natural acoustic habitats, 
with researchers quantifying reduced detection of important ecological 
cues (e.g., Slabbekoorn et al., 2010; Francis and Barber, 2013) as well 
as survivorship consequences in several species (e.g., Simpson et al., 
2014; Nedelec et al., 2015).
    Sound produced from construction activities in the CVOW-C project 
area may be widely dispersed or concentrated in small areas for varying 
periods. However, anthropogenic noise from construction activities in 
the project area would be intermittent and temporary. There would be 
breaks between noise-generating activities on active pile driving days. 
Similarly, there would likely be periods of days or weeks without 
construction-related underwater noise.
    Although this proposed rulemaking primarily covers the noise 
produced from construction activities relevant to the CVOW-C project, 
operational noise was a consideration in NMFS' analysis of the project, 
as all 176 turbines would become operational within the effective dates 
(February 5, 2024-February 4, 2029), beginning no sooner than 2025 with 
all turbines expected to be operational by 2027. Once operational, 
offshore wind turbines are known to produce continuous, non-impulsive 
underwater noise, primarily below 1 kHz (Tougaard et al., 2020; 
St[ouml]ber and Thomsen, 2021).
    In both newer, quieter, direct-drive systems (such as what has been 
proposed for CVOW-C) and older generation, geared turbine designs, 
recent scientific studies indicate that operational noise from turbines 
is on the order of 110 to 125 dB re 1 [mu]Pa root-mean-square sound 
pressure level (SPLrms) at an approximate distance of 50 m 
(Tougaard et al., 2020). Recent

[[Page 28695]]

measurements of operational sound generated from wind turbines (direct 
drive, 6 MW, jacket piles) at Block Island wind farm (BIWF) indicate 
average broadband levels of 119 dB at 50 m from the turbine, with 
levels varying with wind speed (HDR, Inc., 2019). Interestingly, 
measurements from BIWF turbines showed operational sound had less tonal 
components compared to European measurements of turbines with gear 
boxes.
    Tougaard et al. (2020) further stated that the operational noise 
produced by WTGs is static in nature and lower than noise produced by 
passing ships. This is a noise source in this region to which marine 
mammals are likely already habituated. Furthermore, operational noise 
levels are likely lower than those ambient levels already present in 
active shipping lanes, such that operational noise would likely only be 
detected in very close proximity to the WTG (Thomsen et al., 2006; 
Tougaard et al., 2020). Similarly, recent measurements from a wind farm 
(3 MW turbines) in China found at above 300 Hz, turbines produced sound 
that was similar to background levels (Zhang et al., 2021). Other 
studies by Jansen and de Jong (2016) and Tougaard et al. (2009) 
determined that, while marine mammals would be able to detect 
operational noise from offshore wind farms (again, based on older 2 MW 
models) for several kilometers, they expected no significant impacts on 
individual survival, population viability, marine mammal distribution, 
or the behavior of the animals considered in their study (harbor 
porpoises and harbor seals).
    More recently, St[ouml]ber and Thomsen (2021) used monitoring data 
and modeling to estimate noise generated by more recently developed, 
larger (10 MW) direct-drive WTGs. Their findings, similar to Tougaard 
et al. (2020), demonstrate that there is a trend that operational noise 
increases with turbine size. Their study predicts broadband source 
levels could exceed 170 dB SPLrms for a 10 MW WTG; however, 
those noise levels were generated based on geared turbines; newer 
turbines operate with direct drive technology. The shift from using 
gear boxes to direct drive technology is expected to reduce the levels 
by 10 dB. The findings in the St[ouml]ber and Thomsen (2021) study have 
not been experimentally validated, though the modeling (using largely 
geared turbines) performed by Tougaard et al. (2020) yields similar 
results for a hypothetical 10 MW WTG. Overall, noise from operating 
turbines would raise ambient noise levels in the immediate vicinity of 
the turbines; however, the spatial extent of increased noise levels 
would be limited. While Dominion Energy did not request and NMFS is not 
proposing to authorize take incidental to operation noise as noise 
levels are anticipated to dissipate quickly, NMFS proposes to require 
Dominion Energy to measure operational noise levels to confirm these 
assumptions
Water Quality
    Impacts to the immediate substrate during installation of piles are 
anticipated, but these would be limited to minor, temporary suspension 
of sediments, which could impact water quality and visibility for a 
short amount of time but which would not be expected to have any 
effects on individual marine mammals. Given there are no UXO/MEC 
detonations proposed by Dominion Energy, we do not expect any direct or 
indirect effects of explosives and unexploded ordnance to marine 
mammals via sediment to occur. Furthermore, we do not expect any 
contamination of water from UXOs/MECs as none would be detonated during 
this project.
    Equipment used by Dominion Energy within the project area, 
including ships and other marine vessels, potentially aircrafts, and 
other equipment, are also potential sources of chemical by-products. 
All equipment is required to be properly maintained in accordance with 
applicable legal requirements. All such operating equipment would be 
required to meet Federal water quality standards, where applicable.
Reef Effects
    The presence of the WTG and OSS foundations for CVOW-C, scour 
protection, and cable protection will result in a conversion of the 
existing sandy bottom habitat to a hard bottom habitat with areas of 
vertical structural relief (Dominion Energy, 2022). This could 
potentially alter the existing habitat by creating an ``artificial reef 
effect'' that results in colonization by assemblages of both sessile 
and mobile animals within the new hard-bottom habitat (Wilhelmsson et 
al., 2006; Reubens et al., 2013; Bergstr[ouml]m et al., 2014; Coates et 
al., 2014).
    Artificial structures can create increased habitat heterogeneity 
important for species diversity and density (Langhamer, 2012). The WTG 
and OSS foundations will extend through the water column, which may 
serve to increase settlement of meroplankton or planktonic larvae on 
the structures in both the pelagic and benthic zones (Boehlert and 
Gill, 2010). Fish and invertebrate species are also likely to aggregate 
around the foundations and scour protection which could provide 
increased prey availability and structural habitat (Boehlert and Gill, 
2010; Bonar et al., 2015).
    Numerous studies have documented significantly higher fish 
concentrations including species like cod and pouting (Trisopterus 
luscus), flounder (Platichthys flesus), eelpout (Zoarces viviparus), 
and eel (Anguilla anguilla) near in-water structures than in 
surrounding soft bottom habitat (Langhamer and Wilhelmsson, 2009; 
Bergstr[ouml]m et al., 2013; Reubens et al., 2013). In the German Bight 
portion of the North Sea, fish were most densely congregated near the 
anchorages of jacket foundations, and the structures extending through 
the water column were thought to make it more likely that juvenile or 
larval fish encounter and settle on them (Rhode Island Coastal 
Resources Management Council (RI-CRMC), 2010; Krone et al., 2013). In 
addition, fish can take advantage of the shelter provided by these 
structures while also being exposed to stronger currents created by the 
structures, which generate increased feeding opportunities and 
decreased potential for predation (Wilhelmsson et al., 2006). The 
presence of the foundations and resulting fish aggregations around the 
foundations is expected to be a long-term habitat impact, but the 
increase in prey availability could potentially be beneficial for some 
marine mammals.

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
proposed for authorization, which will inform both NMFS' consideration 
of ``small numbers'' and the negligible impact determination.
    Dominion Energy's activities are expected to result in the 
incidental take, by harassment only, of marine mammals; no serious 
injury or mortality is anticipated or proposed for authorization. 
Except with respect to certain activities not pertinent here, section 
3(18) of the MMPA defines ``harassment'' as any act of pursuit, 
torment, or annoyance, which (i) has the potential to injure a marine 
mammal or marine mammal stock in the wild (Level A harassment); or (ii) 
has the potential to disturb a marine mammal or marine mammal stock in 
the wild by causing disruption of behavioral patterns, including, but 
not limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as noise 
from impact and vibratory pile driving and

[[Page 28696]]

HRG surveys could result in behavioral disturbance. Impacts such as 
masking and TTS can contribute to behavior disturbances. There is also 
some potential for auditory injury (Level A harassment) of mysticetes 
(fin whales, humpback whales, minke whales, sei whales), high frequency 
cetaceans (harbor porpoises), and phocids (gray seals and harbor seals) 
due to their hearing sensitivities and the nature of the activities. As 
described below, the larger distances to the PTS thresholds, when 
considering marine mammal weighting functions, demonstrate this 
potential. For mid-frequency hearing sensitivities, when thresholds and 
weighting and the associated PTS zone sizes are considered, the 
potential for PTS from the noise produced by the project is negligible. 
While NMFS is proposing to authorize Level A harassment and Level B 
harassment, the proposed mitigation and monitoring measures are 
expected to minimize the amount and severity of such taking to the 
extent practicable (see Proposed Mitigation).
    As described previously, no serious injury or mortality is 
anticipated or proposed to be authorized incidental to Dominion 
Energy's specified activities. Pile driving and HRG surveys inherently 
are not considered to have the potential to cause marine mammal 
mortality or serious injury. While, in general, vessel strikes have the 
potential to result in mortality or serious injury to marine mammals, 
given the factors discussed previously and the mitigation and 
monitoring measures required by this proposed rule, the probability of 
a vessel strike is so low as to be discountable. Hence, no mortality or 
serious injury is anticipated or proposed to be authorized. Below we 
describe how the proposed take numbers are estimated.
    For acoustic impacts, we estimate take by considering: (1) acoustic 
thresholds above which the best available science indicates marine 
mammals will be behaviorally harassed or incur some degree of permanent 
hearing impairment; (2) the area or volume of water that will be 
ensonified above these levels in a day; (3) the density or occurrence 
of marine mammals within these ensonified areas; and (4) the number of 
days of activities. We note that while these factors can contribute to 
a basic calculation to provide an initial prediction of potential 
takes, additional information that can qualitatively inform take 
estimates is also sometimes available (e.g., previous monitoring 
results or average group size). Below, we describe the factors 
considered here in more detail and present the proposed take estimates.
    In this case, as described below, there are multiple lines of data 
with which to address density or occurrence and, for each species and 
activity, the largest value resulting from the three take estimation 
methods described below (i.e., density-based, PSO-based, or mean group 
size) was carried forward as the amount of requested take, by Level B 
harassment. The amount of requested take, by Level A harassment, 
reflects the density-based exposure estimates and, for some species and 
activities, consideration of the effectiveness of mitigation measures 
to avoid or minimize the potential for injury.
    Below, we describe the acoustic thresholds NMFS uses, discuss the 
marine mammal density and occurrence/group size information used, and 
then describe the modeling and methodologies applied to estimate take 
for each of Dominion Energy's proposed construction activities. NMFS 
has carefully considered all information and analysis presented by the 
applicant as well as all other applicable information and, based on the 
best available science, concurs that the applicant's estimates of the 
types and amounts of take for each species and stock are reasonable and 
is what NMFS is proposing to authorize. NMFS notes the take estimates 
described herein for foundation installation can be considered 
conservative as the estimates do not reflect the implementation of 
mitigation (other than sound attenuation device use) and monitoring 
measures for any marine mammal species or stock, with the exception of 
North Atlantic right whale. In the case of North Atlantic right whales, 
NMFS has determined that the potential for Level A harassment (PTS) has 
been reduced to a de minimis likelihood due to the proposed enhanced 
mitigation measures. The amount of take by Level B harassment that is 
proposed to be authorized for North Atlantic right whales does not 
consider the implementation of the enhanced mitigation measures.

Marine Mammal Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment). A summary of all NMFS' thresholds can be found at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Level B Harassment
    Though significantly driven by received level, the onset of 
behavioral disturbance from anthropogenic noise exposure is also 
informed to varying degrees by other factors related to the source or 
exposure context (e.g., frequency, predictability, duty cycle, duration 
of the exposure, signal-to-noise ratio, distance to the source, ambient 
noise, and the receiving animals (hearing, motivation, experience, 
demography, behavior at time of exposure, life stage, depth) and can be 
difficult to predict (e.g., Southall et al., 2007, 2021; Ellison et 
al., 2012). Based on what the available science indicates and the 
practical need to use a threshold based on a metric that is both 
predictable and measurable for most activities, NMFS typically uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS generally predicts that marine 
mammals are likely to be behaviorally harassed in a manner considered 
to be Level B harassment when exposed to underwater anthropogenic noise 
above the received root-mean-square sound pressure levels (RMS SPL) of 
120 dB (referenced to 1 micropascal (re 1 [mu]Pa)) for continuous 
(e.g., vibratory pile-driving, drilling) and above the received RMS SPL 
160 dB re: 1 [mu]Pa for non-explosive impulsive (e.g., seismic airguns) 
or intermittent (e.g., scientific sonar) sources. Generally speaking, 
Level B harassment take estimates based on these behavioral harassment 
thresholds are expected to include any likely takes by TTS as, in most 
cases, the likelihood of TTS occurs at distances from the source less 
than those at which behavioral harassment is likely. TTS of a 
sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavior patterns that would not otherwise occur.
    Dominion Energy's construction activities include the use of 
continuous (e.g., vibratory pile driving) and intermittent (e.g., 
impact pile driving, HRG acoustic sources) sources, and, therefore, the 
120 and 160 dB re 1 [mu]Pa (rms) thresholds are applicable.
Level A Harassment
    NMFS' Technical Guidance for Assessing the Effects of Anthropogenic 
Sound on Marine Mammal Hearing (Version 2.0) (Technical Guidance, 2018) 
identifies dual criteria to assess auditory injury (Level A harassment) 
to five different marine mammal groups

[[Page 28697]]

(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). As dual 
metrics, NMFS considers onset of PTS (Level A harassment) to have 
occurred when either one of the two metrics is exceeded (i.e., metric 
resulting in the largest isopleth). Dominion Energy's proposed 
activities include the use of non-impulsive sources.
    These thresholds are provided in Table 9 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                                Table 9--Onset of Permanent Threshold Shift (PTS)
                                                  [NMFS, 2018]
----------------------------------------------------------------------------------------------------------------
                                                         PTS onset thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lp,0-pk,flat: 219   Cell 2: LE,p, LF,24h: 199 dB.
                                          dB; LE,p, LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lp,0-pk,flat: 230   Cell 4: LE,p, MF,24h: 198 dB.
                                          dB; LE,p, MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lp,0-pk,flat: 202   Cell 4: LE,p, HF,24h: 198 dB.
                                          dB; LE,p,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lp,0-pk.flat: 218   Cell 8: LE,p,PW,24h: 201 dB.
                                          dB; LE,p,PW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS
  onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
  associated with impulsive sounds, these thresholds are recommended for consideration.
Note: Peak sound pressure level (L0-pk) has a reference value of 1 [mu]Pa, and weighted cumulative sound
  exposure level (LE,) has a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO, 2017). The subscript
  ``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within the
  generalized hearing range of marine mammals (i.e., 7 Hz to 160 kHz). The subscript associated with cumulative
  sound exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF,
  and HF cetaceans, and PW pinnipeds) and that the recommended accumulation period is 24 hours. The weighted
  cumulative sound exposure level thresholds could be exceeded in a multitude of ways (i.e., varying exposure
  levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate the
  conditions under which these thresholds will be exceeded.

    As Dominion Energy has not requested, and NMFS has not proposed to 
authorize any take related to the detonation of UXOs/MECs, the acoustic 
(i.e., PTS onset and TTS onset for underwater explosives) and the 
pressure thresholds (i.e., lung and gastrointestinal tract injuries) 
are not discussed or included in this proposed action.

Acoustic and Exposure Modeling Methods

    As described above, underwater noise associated with the 
construction of offshore components of CVOW-C would predominantly 
result from installation of the WTG monopile and the OSS jacket 
foundations using a dual-vibratory and impact pile driving approach 
while noise from cable landfall construction activities (i.e., 
temporary cofferdam and temporary goal post installation and removal) 
will primarily result from either impact pile driving (for the 
temporary goal posts) or vibratory pile driving (for the temporary 
cofferdams). Acoustic modeling was performed for some activities for 
which there was a pile driving component, including WTG and OSS 
foundation installation and temporary cofferdam installation and 
removal. The basic modeling approach is to characterize the sounds 
produced by the source, determine how the sounds propagate within the 
surrounding water column, and then estimate species-specific exposure 
probability by considering the range- and depth-dependent sound fields 
in relation to animal movement in simulated representative construction 
scenarios.
    Animat exposure modeling was only performed for foundation 
installation. For other proposed activities planned by Dominion Energy 
(i.e., temporary cofferdam installation and removal, temporary goal 
post installation and removal, HRG surveys), take was estimated using a 
``static'' approach, as detailed later in the Static Method section.
    Dominion Energy employed Tetra Tech, Inc. (Tetra Tech) to conduct 
the acoustic modeling and Marine Acoustics, Inc. (MAI) for the animal 
movement modeling to better understand both the sound fields produced 
during foundation and cofferdam installation and to estimate any 
potential exposures (see the Acoustic Modeling report in Appendix A of 
Dominion Energy's ITA application). Dominion Energy also collaborated 
with the Institute for Technical and Applied Physics (iTAP) for 
information related to vibratory pile driving of foundation piles. 
Tetra Tech also performed the acoustic analysis related to temporary 
cofferdam installation via vibratory pile driving. Acoustic source 
modeling of vibratory pile driving related to cofferdam installation 
and removal was used in conjunction with static methods to yield 
estimated and requested take values. The approach undertaken by Tetra 
Tech to determine the sound source of impact pile driving of WTG 
foundations was originally applied to the CVOW Pilot Project, and 
subsequently modified based on newly available data and the additional 
availability of research studies. This revised approach is summarized 
here; more detail can be found in the Acoustic Modeling report in 
Appendix A of Dominion Energy's ITA application.
Acoustic Source Modeling
    Based on a literature review of pile driving measurement reports, 
theoretical modeling reports, and peer-reviewed research papers (see 
the references in Attachment Z-2 in Appendix A of Dominion Energy's COP 
(2023)), Tetra Tech developed an empirical modeling approach for 
calculating the acoustic source of impact pile driving foundation 
installation activities proposed for the CVOW-C project. A 
collaboration between Dominion Energy and iTAP assessed the estimated 
acoustic source levels produced from vibratory pile driving of 
foundation piles based on empirical data collected and assessed from 
the CVOW Pilot Project and other European offshore wind farms. These 
two modeling approaches are discussed separately here.

[[Page 28698]]

Foundation Impact Pile Driving Source Level Empirical Model

    An empirical model developed by Tetra Tech was used to determine 
the peak sound level (Lpk) and sound exposure level (SEL) 
sound source levels for the foundation pile driving scenarios. To feed 
into the model, Tetra Tech obtained sound levels from relevant 
scenarios for a variety of pile diameter sizes, driven with hammers of 
varying energies, and collected or analyzed at different ranges from 
the impacted pile. This empirical model was implemented by using the 
following steps:
    1. Normalizing the received sound pressure levels to a common 
received range, assuming a transmission loss of 15LogR, where R is the 
distance ratio;
    2. Scaling the source levels to an energy of 4,000 kJ, assuming a 
relationship between the hammer energy and radiated sound as 10 times 
the base 10 logarithm of the ratio of hammer energy to the referenced 
hammer energy (as in the scaling laws outlined in von Pein et al., 
2022); and
    3. Calculating a linear regression of the adjusted source levels 
(which has been normalized for range and hammer energy) as a function 
of the base 10 logarithm of the pile diameters, which is then used to 
predict the broadband SEL and peak sound levels for the planned energy 
and diameter.
    Pile driving sound source levels were represented using three 
different sound metrics: Lpk, SEL, and sound pressure level 
(SPL). One-third octave band levels from 12.5 Hz to 20 kHz were derived 
from surrogate spectra taken from published data for piles of similar 
diameters, and adjusted based on the empirical model above. For the 
Lpk underwater acoustic modeling scenario (evaluating a 
single pile-driving strike), the pile driving sound source was 
represented as a point source at a mid-water depth. To estimate SEL, 
the monopile and pin pile driving scenarios were modeled using a 
vertical array of point sources spaced at 1 m intervals and assuming a 
specific number of strikes for each type of pile (see Formula 2 in 
Attachment Z-1 of Appendix A in the application). The SPL scenario was 
set up in an identical manner to the SEL scenario, with the primary 
difference being that the model did not incorporate the total number of 
pile driving strikes needed for each of the monopile and pin pile 
scenarios within a 24-hour period. Instead, only a single pile driving 
strike was incorporated.
    Information on the impact pile driving scenarios and source levels 
for WTGs, OSSs, and goal posts can be found in Table Z-7 of Appendix A 
of Dominion Energy's ITA application. These impact modeling scenarios 
assumed no sound attenuation. For all WTG monopile modeling (i.e., 
Scenarios 1-3 including standard driving and hard-to-drive installation 
approaches), a SEL source level of 226 was assumed. For OSS modeling 
using pin piles, 214 dB was assumed. For goal post installation, a SEL 
source level of 183 dB was assumed (California Department of 
Transportation (CALTRANS), 2015).

Foundation Vibratory Pile Driving Source Level Empirical Model

    Limited empirical data exists for the installation of foundation 
piles by vibratory driving, with most being measured by iTAP (see 
Remmers and Bellmann (2021) in Appendix A of the application 
(Attachment Z-3)). Current datasets contain a variety of different 
information, including ranges of water depths from several meters to 
depths of 40 m, different sediment types, and measured receiver 
distances from several meters away from the source up to 750 m away.
    To predict the expected underwater noise levels during vibratory 
pile driving of 2.4 m pin piles for the OSS and 9.5 m monopiles, iTAP 
used the limited empirical data from several existing offshore wind 
farms from different pile diameters. All data were normalized to a 
distance from the source of 750 m assuming a propagation loss of 
15LogR, where R is the distance ratio. Given this normalization, 
uncertainties of <3 dB were expected. The data were plotted as a 
function of the pile diameter and then fit with a statistical 
regression curve (see the figure in Remmers and Bellmann (2021) 
Attachment Z-3 in Appendix A of Dominion Energy's application). Using 
the resulting regression, iTAP predicted noise levels of 151 dB SPL for 
2.4 m pin piles and 159 dB SPL for 9.5 m monopiles, at a range of 750 m 
from the driven piles (Remmers and Bellmann (2021)). Based on possible 
influences of friction between the head of the vibratory hammer and the 
top of the piles, iTAP states that these results at 750 m from the 
piles may be overestimating the source level for vibratory pile 
driving.
    For vibratory installation of cofferdams, adjusted one-third-octave 
band source levels (with a broadband source level of 195 dB SEL) 
obtained from similar offshore construction projects and then adjusted 
to account for the estimated force needed to drive cofferdam sheet 
piles (see Schultz-von Glahn et al., 2006).
Acoustic Propagation Modeling
    To predict acoustic levels at range during foundation installation 
(impact and vibratory pile driving) and temporary cofferdam 
installation and removal (vibratory pile driving), Tetra Tech used 
sound propagation models, discussed below. For the installation and 
removal of goal posts and HRG surveys, Dominion Energy assumed a 
practical spreading loss rate (15logR). Below we describe the more 
sophisticated sound propagation modeling methodology.
    Tetra Tech utilized a software called dBSea, which was developed by 
Marshall Day Acoustics (https://www.dbsea.co.uk/), to predict the 
underwater noise in similar environments to what might be encountered 
at the CVOW-C project site. Per Attachment Z-1 of the COP, Tetra Tech 
used different ``solvers'' (i.e., algorithms) for the low and high-
frequency ranges, including:
     dBSeaPE (Parabolic Equation Method): The dBSeaPE solver 
makes use of the range-dependent acoustic model (RAM) parabolic 
equation method, a versatile and robust method of marching the sound 
field out in range from the sound source. This method is one of the 
most widely used in the underwater acoustics community, offers 
excellent performance in terms of speed and accuracy in a range of 
challenging scenarios, and was used for low frequencies.
     dBSeaRay (Ray Tracing Method): The dBSeaRay solver forms a 
solution by tracing rays from the source to the receiver. Many rays 
leave the source covering a range of angles, and the sound level at 
each point in the receiving field is calculated by coherently summing 
the components from each ray. This is currently the only 
computationally efficient method at high frequencies.
    Each model utilizes imported environmental data and manually placed 
noise sources in the aquatic environment, which could consist of either 
equipment in the standard dBSea database or a user-specific database 
(i.e., the empirically determined source levels and spectra, discussed 
above). The software then allows the user to include properties 
specific to the project site including bathymetry, seabed, and water 
column characteristics (e.g., sound speed profiles, temperature, 
salinity, and current). Tetra Tech also incorporated variables for each 
pile to account for the soft-start of impact pile driving of foundation 
piles and pile penetration progression.

[[Page 28699]]

    For the CVOW-C project's modeled environment using dBSea, 
bathymetry data was obtained by Tetra Tech from the National 
Geophysical Data Center and U.S. Coastal Relief Model (NOAA Satellite 
and Information Service, 2020) and consisted of a horizontal resolution 
of 3 arc seconds (defined as 90 m (295.28 ft)). The data covered an 
area consisting of 138 km x 144 km (452,755.91 ft x 472,440.94 ft) with 
a maximum depth of 459 m (1,505.91 ft). Sound sources were placed near 
the middle of the bathymetry area. The bathymetry data was imported 
into the dBSea model and extents were set for displaying the received 
sound levels. Relatedly, sediment data was also included into the model 
as bottom sedimentation has the potential to directly impact the sound 
propagation. Dominion Energy's site assessment surveys revealed the 
project area primarily consists of a predominantly sandy seabed. While 
not reiterated here, Appendix A of Dominion Energy's application 
contains the tables that include the geoacoustic properties of the sub-
bottom sediments for modeling scenarios involving the more offshore WTG 
and OSS foundations (see Table Z-5) and for the nearshore temporary 
cofferdams (see Table Z-6).
    Given that the sound speed profile in an aquatic environment varies 
throughout the year, Tetra Tech calculated seasonal sound speed 
profiles based on the proposed installation schedule presented for the 
CVOW-C project. Dominion Energy would only install WTG and OSS 
foundations between May 1st and October 31st, annually, hence an 
average sound speed profile was calculated for this time period. Sound 
speed profile data was obtained from the NOAA Sound Speed Manager 
software incorporating World Ocean Atlantic 2009 extension algorithms. 
A sensitivity analysis was performed on the monthly sound speed 
information to determine the most conservative sound modeling results. 
The average sound speed profile obtained from this dataset was directly 
included into the dBSea model (see Figure 3 in Attachment Z-1 in 
Dominion Energy's application (Appendix A)). This same approach was 
undertaken for temporary cofferdam installation.
    The scenarios for WTG monopile and OSS jacket pin pile installation 
were modeled using a vertical array (based on third-octave band sound 
characteristics that was adjusted for site-specific parameters, 
including expected hammer energy and the number of hammers strikes 
needed per each scenario) of point sources spaced at 1-m intervals. 
Each of the third octave band center frequencies from 12.5 Hz up to 20 
kHz, of the source spectra, was modeled. In order to more closely match 
expected sound propagation characteristics of the source signal, a 
constant 15 dB/decade roll-off filter is applied to the modeled spectra 
after the second spectral peak. The spectra source levels for impact 
driving of monopile and pin piles can be found in Figure 10 of the 
CVOW-C ITA application. The vibratory pile driving spectra, which is 
available in Figure 11 of the ITA application, used reference 
information from iTAP (Gerke and Bellmann, 2012), the California 
Department of Transportation (CALTRANS, 2015), and from measurements of 
vibratory driving collected by Tetra Tech. Based on the description 
above, Tetra Tech determined an appropriate sound speed profile to 
input into dBSea by pulling the average sound speed profile for the 
construction period (May 1st to October 31st), following the schedule 
provided by Dominion Energy. No information was pulled for November 1st 
through April 30th, as no pile driving is planned due to seasonal 
restrictions regarding the North Atlantic right whale. The monthly 
sound speed profile for the planned WTG and OSS foundation construction 
period is found in Figure 12 in the CVOW-C ITA application.
    The sound level estimates are calculated from the generated three-
dimensional sound fields and then, at each sampling range, the maximum 
received level that occurs within the water column is used as the 
received level at that range. The dBSea model allows for a maximum 
received level-over-depth approach (i.e., the maximum received level 
that occurs within the water column at each calculation point). These 
maximum-over-depth (Rmax) values are then compared to 
predetermined threshold levels to determine exposure and acoustic 
ranges to Level A harassment and Level B harassment threshold 
isopleths. However, the ranges to a threshold typically differ among 
radii from a source and also might not be continuous along a radii 
because sound levels may drop below threshold at some ranges and then 
exceed threshold at farther ranges. Both the Rmax (the 
maximum range in the model at which the sound level was calculated) and 
R95 (excludes ends of protruding areas or small 
isolated acoustic foci not representative of the nominal ensonified 
zone) were calculated for each of the relevant regulatory thresholds. 
The difference between Rmax and R95 
depends on the source directivity and the heterogeneity of the acoustic 
environment. To minimize the influence of these inconsistencies, 5 
percent of the farthest such footprints were excluded from the model 
data. The resulting range, R95, was chosen to 
identify the area over which marine mammals may be exposed above a 
given threshold because, regardless of the shape of the maximum-over-
depth footprint, the predicted range encompasses at least 95 percent of 
the horizontal area that would be exposed to sound at or above the 
specified threshold. The difference between Rmax and 
R95 depends on the source directivity and the 
heterogeneity of the acoustic environment.
    Here we note that Tetra Tech and MAI did not calculate or provide 
exposure ranges to the Level A harassment SELcum thresholds 
in the ITA application as provided by other offshore wind developers in 
their ITA application. Instead, Dominion Energy chose to utilize 
acoustic ranges (R95) values in its analysis, which 
NMFS concurs is also a reasonable approach and likely results in 
somewhat comparatively larger zones. Dominion Energy's application, and 
this proposed rule, include the R95 ranges as these 
are representative of the expected underwater acoustic footprints 
during foundation and cofferdam installation.
    Temporary cofferdams followed a similarly described approach. To 
estimate the distances to the harassment isopleths from the vibratory 
installation of sheet piles, it was assumed that the vibratory pile 
driver would use approximately 1,800 kilonewtons of vibratory force 
over 60 minutes. Given the close proximity of all temporary cofferdams 
in the nearshore environment and the relatively same installation depth 
(3.3. m), a single representative location (i.e., the centermost 
cofferdam) was used for the modeling analysis.
    As previously described above, unique environmental inputs can be 
included into dBSea to provide a more project-specific output. Tetra 
Tech input bathymetry data, which was obtained from the National 
Geophysical Data Center (NGDC) and the U.S. Coastal Relief Model (NOAA 
Satellite and Information Service, 2020) with a horizontal resolution 
of 3 arc seconds (approximately 90 m). The bathymetry data were sampled 
through the creation of a fan of radials at specifically given angular 
spacings, which was in turn used to determine depth points as each of 
the modeling transects.
    Sediment data was included as determined to be specific to the 
CVOW-C project area (i.e., predominately sand), which were informed due 
to past

[[Page 28700]]

geotechnical surveys completed in support of the adjacent CVOW Pilot 
Project. The sediment layers incorporated into the dBSea model can be 
found in Table 28 of Dominion Energy's ITA application.
    To determine the appropriate sound speed profile, Tetra Tech looked 
toward Dominion Energy's construction schedule, which states that 
temporary cofferdams would be installed and removed from Q1 to Q4 of 
2024, but most likely between May 1st and October 31st. As this period 
is the same period of time where the 2024 foundation installation 
activities would be occurring, Tetra Tech incorporated the same average 
sound speed profile used for WTG and OSS foundation installation (see 
Figure 12 in Dominion Energy's ITA application). As no pile driving of 
any type is planned to occur from November to April, these months were 
not incorporated into the sound speed profile analysis. As was 
previously described for foundation installation, the speed of sound 
profile information was obtained using the NOAA Sound Speed Manager 
software, which incorporated the World Ocean Atlantic 2009 extension 
algorithms.
    To calculate the ranges to the defined acoustic thresholds, Tetra 
Tech utilized a maximum received level-over-depth approach where the 
maximum received sound level that occurs within the water column at 
each sampling point was used. Tetra Tech calculated both the 
Rmax and the R95 for each of the marine 
mammal regulatory thresholds.
Animal Movement Modeling
    To estimate the probability of exposure of animals to sound above 
NMFS' harassment thresholds during foundation installation, MAI 
integrated the sound fields generated from the source and propagation 
models described above with marine mammal species-typical behavioral 
parameters (e.g., dive parameters, swimming speed, and course/direction 
changes). Animal movement modeling was performed for all marine mammal 
species determined to potentially occur within the CVOW-C project area 
to estimate the amount of potential acoustic exposures above NMFS' 
Level A (PTS) harassment and Level B (behavioral) harassment 
thresholds. Animat modeling was conducted for four scenarios (three for 
WTGs, one for OSS) that were determined to be representative of the 
types of construction activities expected at three different locations 
(two for WTGs (one shallow (21 m (69 ft)) and one deep (37 m (121 ft)) 
location) and one for OSSs (28 m (92 ft))). These locations were 
selected to appropriately observe the range of effects of sound 
propagation. The modeled areas are shown in Figure Z-4 in Dominion 
Energy's Underwater Acoustic Assessment (Appendix A in the 
application).
    MAI's animat modeling was conducted using the Acoustic Integration 
Model (AIM; Frankel et al., 2002), which is a Monte Carlo based 
statistical model in which multiple iterations of realistic predictions 
of acoustic source use as well as animal distribution and movement 
patterns are conducted to provide statistical predictions of estimated 
effects from exposure to underwater sound transmissions. By using AIM, 
each acoustic source and receiver were modeled using the same concept 
as animats. For each species, separate AIM simulations were developed 
and iterated for each modeling scenario and activity location. During 
the simulations, animats were randomly distributed of the model 
simulation area and the predicted received sound level was estimated 
every 30 seconds to create a history over a 24-hour period. Animats 
were also pre-programmed to move every 30 seconds based upon species-
specific behaviors. At the end of each 30 second interval, the received 
sound level (in dB RMS) for each animat was recorded.
    Animats that exceed NMFS' acoustic thresholds were identified and 
the range for the exceedances determined. The output of the simulation 
is the exposure history for each animat within the simulation, and the 
combined history of all animats gives a probability density function of 
exposure during the project. The number of animals expected to exceed 
the regulatory thresholds is determined by scaling the probability of 
exposure by the species-specific density of animals in the area. By 
programming animats to behave like marine species that may be exposed 
to foundation installation noise during pile driving, the animats are 
exposed to the sound fields in a manner similar to that expected for 
real animals.

Static Take Estimate Method

    Take estimates from cable landfall construction activities 
(cofferdam and goal post installation and removal) and HRG surveys were 
calculated based on a static method (i.e., animal movement modeling was 
not conducted for these activities). Take estimates produced using the 
static method are the product of density, ensonified area, and number 
of days of pile driving work. Specifically, take estimates are 
calculated by multiplying the expected densities of marine mammals in 
the activity area(s) by the area of water likely to be ensonified above 
the NMFS defined threshold levels in a single day (24-hour period). 
Next that product is multiplied by the number of days pile driving is 
likely to occur. A summary of this method is illustrated in the 
following formula:

Estimated Take = D x ZOI x # of days

Where:

D = average species density (per 100 km\2\); and
ZOI = maximum daily ensonified area to relevant thresholds.

    This methodology was utilized for impact pile driving associated 
with goal posts, vibratory pile driving associated with temporary 
cofferdams, and active acoustic source use from HRG surveys as no 
exposure modeling was conducted.

Density and Occurrence

    In this section, we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. As noted above, depending on the species and activity 
type and as described in the take estimation section for each activity 
type, the requested amount of take, and which NMFS proposes to 
authorize, is based on the highest estimate of take resulting from full 
consideration of density models, average group sizes, or site-specific 
survey data.
    Dominion Energy applied the Duke University Marine Geospatial 
Ecology Laboratory marine mammal habitat-based density models (https://seamap.env.duke.edu/models/Duke/EC/ EC/) to estimate take from WTG and OSS 
foundation installation, temporary goal post installation and removal, 
temporary cofferdam installation and removal, and HRG surveys.
    The Duke habitat-based density models delineate species' density 
into 5 x 5 km (3.1 x 3.1 mi) grid cells (as opposed to the 10 x 10 km 
(6.2 x 6.2 mi) grid cells previously used in past Roberts et al. 
datasets for all species, with exception for the North Atlantic right 
whale). Although the density grid cells are 25 km\2\ (9.7 mi\2\), the 
values are still reported per 100 km\2\ (38.6 mi\2\). Based on the area 
across which different specified activities are conducted (i.e., WTG 
and OSS foundation installation, nearshore cable landfall activities, 
and HRG surveys), appropriate averaged density estimates are applied to 
exposure and/or take calculations for each area.
    For foundation installation, densities were extracted from grid 
cells within the Lease Area and those extending 8.9

[[Page 28701]]

km (5.53 mi) beyond the Lease Area boundaries. The grid cells within 
the 8.9 km perimeter area were incorporated to account for the largest 
ensonified area to the Level B harassment threshold; thereby 
representing the furthest extent where potential impacts to marine 
mammals could be expected. The density in the grid cells selected were 
averaged for each month to provide a mean monthly density for each 
marine mammal species and/or stock. In some cases, the density models 
combine multiple species (i.e., long-finned and short-finned pilot 
whales, gray and harbor seals) or stocks (i.e., Southern migratory 
coastal and the Western North Atlantic offshore bottlenose dolphin 
stocks), or it may not be possible to derive monthly/seasonal densities 
for some species so annual densities were used instead (i.e., 
pantropical spotted dolphins, pilot whale spp.).
Group Size and PSO Data Considerations
    The exposure estimates from the animal movement modeling or static 
methods described above directly informed the take estimates. In some 
cases, adjustments to the density-based exposure estimates may be 
necessary to fully account for all animals that could be taken during 
the specified activities. This could consist of an adjustment based on 
species group size or observations or acoustic detections provided in 
monitoring reports.
    For some species, observational data from Protected Species 
Observers (PSOs) aboard HRG survey vessels indicate that the density-
based exposure estimates may be insufficient to account for the number 
of individuals or type of species that may be encountered during the 
planned activities. As an example, pantropical spotted dolphins have 
been included in the requested take request based on prior PSO 
observation data, obtained via the 2020-2021 monitoring report from 
under previously issued (and subsequently modified) HRG IHAs to 
Dominion Energy occurring in and around the Lease Area (see RPS Group 
(RPS) (2018), AIS, Inc. (2020), and RPS (2021)). For other less-common 
species, the predicted densities from Roberts and Halpin (2022) are 
very low and the resulting density-based exposure estimate was less 
than a single animal or a typical group size for the species. In such 
cases, the mean group size was considered as an alternative to the 
density-based take estimates to account for potential impacts on a 
group during an activity.
    Regardless of methodology used (i.e., density-based, group size, 
PSO data), Dominion Energy requested, and NMFS proposes to authorize, 
take based on the highest amount of exposures estimated from any given 
method. Below we present the results of the methodologies described 
above, including distances to NMFS thresholds and take estimates 
associated with each activity.

WTG and OSS Foundation Installation

    Here, we present the construction scenarios Dominion Energy applied 
to its analysis, which NMFS is carrying forward in this proposed rule, 
and the resulting acoustic ranges to Level A harassment and Level B 
harassment thresholds, exposure estimates, and take estimates from WTG 
and OSS foundation installation following the aforementioned modeling 
methodologies.
    To complete the project, Dominion Energy has proposed four 
foundation installation construction schedules (three for WTG 
installation and one for OSS installation), as construction schedules 
cannot be fully predicted due to uncontrollable environmental factors 
(e.g., weather) and installation schedules include variability (e.g., 
due to drivability). Since three locations had been identified where 
OSSs would be constructed, the modeling relied on a single site that 
would result in the further propagation distance. This site was 
determined to be representative of all three OSS locations.
    For the monopile scenarios, two types of pile driving conditions 
are expected for each monopile installed: a standard pile driving 
situation (Scenario 1) and a hard-to-drive (Scenario 2) situation. 
During the installation of one monopile for WTG foundations per day, 
either a standard or hard-to-drive scenario may be necessary, which 
would determine the duration of vibratory driving and the number of 
impact hammer strikes needed. In situations where two monopile WTGs 
would be installed per day (i.e., Scenario 3), Dominion Energy assumed 
that only one monopile would consist of a hard-to-drive scenario and 
the other would always be a standard. Dominion Energy has committed to 
not installing two hard-to-drive foundations in a single day. For OSS 
jacket foundations, a single installation approach (i.e., Scenario 4; 
impact pile driving only) is expected for the installation of up to two 
pin piles per day.
    Dominion Energy has assumed that a maximum of two monopiles may be 
installed per day or that a maximum of two pin piles would be installed 
per day. No concurrent pile driving would occur. Due to the risk of 
pile run, Dominion Energy expects to utilize a joint vibratory-impact 
pile driving installation approach on all WTG and OSS foundation piles. 
All scenarios, including associated pile driving details, expected to 
occur can be found in Table 10 below.

                             Table 10--WTG and OSS Foundation Installation Scenarios
----------------------------------------------------------------------------------------------------------------
                                                                                                 Duration of
      Installation scenario        Foundation installed         Installation details            installation
                                            \c\                                                 activity \a\
----------------------------------------------------------------------------------------------------------------
Scenario 1: Standard Driving.....  9.5 m diameter        Vibratory pile driving...........  60 minutes.
                                    monopile foundation  Impact pile driving..............  3,240 hammer strikes
                                    (1 pile per day).                                        (4,000 kJ).
Scenario 2: Hard-to-drive........  9.5 m diameter        Vibratory pile driving...........  30 minutes.
                                    monopile foundation  Impact pile driving..............  3,720 hammer strikes
                                    (1 pile per day).                                        (4,000 kJ).
Scenario 3: One standard and one   9.5 m diameter        Vibratory pile driving...........  90 minutes.
 hard-to-drive \b\.                 monopile             Impact pile driving..............  6,960 hammer strikes
                                    foundations (2                                           (4,000 kJ).
                                    piles per day).
Scenario 4: OSS Jacket Foundation  2.8 m diameter pin    Vibratory pile driving...........  120 minutes.
                                    piles (2 piles per   Impact pile driving..............  15,120 hammer
                                    day).                                                    strikes (3,000 kJ).
----------------------------------------------------------------------------------------------------------------
\a\ The hammer energy of 4,000 kJ represents the maximum hammer energy; however, Dominion Energy anticipates the
  energy will be less than this.
\b\ Two hard-to-drive piles would never be installed on the same day.
\c\ Dominion Energy may build up to two foundations per day, consisting of either WTG monopiles or pin piles per
  jacket foundations. However, on some days, only one monopile may be built per day and would consist of a
  single standard driven pile or a hard-to-drive pile.

    As described above, underwater noise associated with the 
construction of offshore components of CVOW-C would predominantly 
result from vibratory and impact pile driving monopile and jacket 
foundations. As previously described,

[[Page 28702]]

Dominion Energy employed Tetra Tech to conduct acoustic modeling and 
MAI to conduct animal movement exposure modeling to better understand 
sound fields produced during these activities and to estimate 
exposures. For installation of foundation piles, animal movement 
modeling was used to estimate exposures.
    Presented below are the acoustic ranges to the Level A harassment 
and Level B harassment thresholds for WTG installation in the deeper 
environment (Table 11), WTG installation in the shallower water (Table 
12), and OSS installation in the single representative location (Table 
13). All ranges shown are assuming 10 dB of sound attenuation as 
Dominion Energy would employ a noise attenuation system during all 
vibratory and impact pile driving of monopile and jacket foundations. 
Although three attenuation levels were evaluated and Dominion Energy 
has not yet finalized its mitigation strategy, Dominion Energy and NMFS 
both anticipate that the noise attenuation system ultimately chosen 
will be capable of reliably reducing source levels by 10 dB. Therefore, 
modeling results assuming 10-dB attenuation are carried forward in this 
analysis for WTG and OSS foundation installation. See the Proposed 
Mitigation section for more information regarding the justification for 
the 10 dB assumption.
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    Dominion Energy provided seasonal density estimates during the time 
of year when WTG and OSS foundations would be installed following the 
methodology provided in the Density and Occurrence section above. The 
resulting densities used in the exposure estimate calculations for 
foundation installation are provided in Table 14.
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    MAI set the modeled marine mammal animats to populate each of the 
model areas with the representative nominal densities provided. During 
the modeling, some of the obtained densities were higher than the real-
world density, as to ensure that the results of the animat model 
simulations were not unduly influenced by the spontaneous placement of 
some of the simulated marine mammals and to provide additional 
statistical robustness within the modeling exercise. To obtain the 
final exposure estimates, the modeled results were normalized by the 
ratio of the modeled animat density to the real-world seasonal 
densities. The exposure estimates were derived based on the history of 
exposure within the modeling exercise for each marine mammal species or 
species group. The modeled sound exposure level (SEL) received by each 
animat over the duration of the construction activity period (e.g., 
estimated 3 hours of driving on a single monopile) and the peak sound 
pressure level were used to calculate the potential for an individual 
animat to have experienced PTS, in accordance with the NOAA Fisheries 
(2018) physiological acoustic thresholds for marine mammals. If an 
animat was not predicted to have experienced PTS, then the sound energy 
received by each individual animat over the 24-hour modeled period was 
used to assess the potential risk of biologically significant 
behavioral reactions. The modeled RMS sound pressure levels were used 
to estimate the potential for behavioral responses, in accordance with 
the NOAA Fisheries (2005b) behavioral criteria.
    For the monopile WTG installation, the exposure calculations 
assumed 176 WTG monopiles would be installed over two years, but also 
took into account the need for Dominion Energy to possibly re-pile for 
up to seven WTG foundations (equating to a total of 183 modeled piling 
events for WTGs). For the jacket foundations using pin piles for the 
OSSs, the modeling assumed that up to 12 pin piles (four per OSS for up 
to three total OSSs) would be installed over two years. Both of these 
were modeled in accordance with the schedule provided by Dominion 
Energy.
    Overall, for Year 1 (2024), it was assumed that up to a maximum of 
95 monopiles and all 12 pin piles would be installed. For Year 2, it 
was assumed that a maximum of 88 monopiles (which does account for the 
seven possible re-piling events that may be necessary) would be 
installed. As construction of the WTGs and OSSs are only anticipated to 
occur in the first two years of the project (2024 and 2025), animats 
were only calculated for these. Although schedule delays due to weather 
or other unforeseen activities may require Dominion Energy to not 
complete all piling in Year 2, but instead push a limited number of 
piles to Year 3 (2026), no modeling was completed for 2026. This is 
because any piles not completed in 2025 (Year 2) would be pushed to 
2026 (Year 3), which means that the current analysis has accounted for 
the total scenario as the analysis for foundation installation 
activities in Year 2 would be less than estimated here and instead 
would shift some to Year 3. Please see Table 15 for the derived 
exposure estimates during WTG and OSS foundation installation over two 
years (2024 and 2025).
    The exposure estimates for both the installation of WTGs and OSSs 
over two years (2024 and 2025) were then adjusted, for some species, 
based on group size characteristics known through the scientific 
literature and received sighting reports from previous projects and/or 
surveys. As indicated below, when density-based take calculations were 
lower than one, estimates were adjusted upwards based on group size, 
when density-based take calculations were too low based on PSO 
observations. The species-specific requested and proposed take 
estimates are listed below:
     North Atlantic right whale: Level B take for foundation 
installation adjusted for group size of 1 individual for months with 
monthly density <0.01 per 100 km\2\ (Roberts and Halpin, 2022) when 
construction may occur (May-October) and 2 individuals for months with 
monthly density >0.01 when construction may occur (May-October);
     Fin whale: Adjusted based on protected species observer 
(PSO) data (max daily number x days of activity);
     Humpback whale: Adjusted based on PSO data (max daily 
number x days of activity);
     Sperm whale: Adjusted based on 1 group size per year (3 
per Barkaszi et al., 2019);
     Atlantic white-sided dolphin: Adjusted based on 1 group 
size per year (15 per Reeves et al., 2002);
     Pantropical spotted dolphin: Adjusted based on 1 group 
size per year (20 per Reeves et al., 2002);
     Short-beaked common dolphin: Adjusted based on 1 group 
size (20 individuals per group) per day (Dominion Energy, 2021);
     Clymene dolphin: Adjusted based on 1 group size (5 per 
AIS, Inc. (2020));
     False killer whale: Adjusted based on 1 group size per 
year (4 per RPS (2021));
     Melon-headed whale: Adjusted based on 1 group size per 
year (5 per RPS (2018)); and
     Pygmy sperm whale: Adjusted based on 1 group size per year 
(1 per RPS (2021)).
    In Table 15, we present the calculated exposure estimates and the 
maximum amount of take proposed for authorization during foundation 
installation of WTGs and OSSs during the proposed five-year effective 
period for the CVOW-C project. As demonstrated by the exposure modeling 
results, which do not consider mitigation other than the use of a sound 
attenuation device(s), the potential for Level A harassment is very 
low. However, there may be some situations where pile driving cannot be 
stopped due to safety concerns related to pile instability.
    As previously discussed, only 176 WTG and 3 OSS (using a maximum of 
12 pin piles) foundations would be permanently installed for the CVOW-C 
project; however, Dominion Energy has considered the possibility that 
some piles may be started but not fully installed at some locations due 
to installation feasibility issues. Conservatively, Dominion Energy has 
estimated up to 7 additional pile driving events may be needed in the 
event this occurs. Per Dominion Energy's estimated construction 
schedule, it is anticipated that all of these foundation installation 
activities would occur in Year 1 (2024) and Year 2 (2025); therefore, 
the take estimates below reflect the foundation pile driving activities 
associated with 183 WTG foundations and 3 OSSs, to account for the 
seven additional re-piling events that may occur if monopiles were 
started in one location but then needed to be re-driven at another WTG 
position.

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BILLING CODE 3510-22-C
    Additionally, as previously discussed above in the Detailed 
Description of Specified Activities section, Dominion Energy's 
construction schedule may shift during the project due to bad weather 
or other uncontrollable and unforeseen events, which may require 
foundation installation to shift and occur in 2026 instead. However, in 
this situation, the maximum amount of take proposed for authorization 
would not change; instead, some of the take that would have occurred in 
2025 would instead occur in 2026, which means that the take of marine 
mammals during 2025 would be less than predicted here, as those takes 
would be shifted into 2026.

Cable Landfall Construction

    Dominion Energy has proposed to install and remove both temporary 
goal posts comprised of steel pipe piles (to guide the placement of 
casing pipes installed using a trenchless installation method that does 
not produce noise levels with the potential to result in marine mammal 
harassment) and temporary cofferdams comprised of steel sheet piles at 
cable landfall locations.

Temporary Cofferdams

    Dominion Energy would install and remove up to nine temporary 
cofferdams adjacent to the firing range at the State Military 
Reservation in Virginia Beach using a vibratory hammer. Dominion Energy 
assumed that a maximum of six days would be needed to install and 
remove a single cofferdam (3 days to install and 3 days to remove). 
Vibratory pile driving would occur for up to 60 minutes per day (1 
hour) and up to 20 sheet piles could be installed per day (each 
cofferdam would necessitate 30 to 40 sheet piles, depending on the 
final chosen configuration). Table 16 includes details for the 
cofferdam scenario.

                                     Table 16--Temporary Cofferdam Scenario
----------------------------------------------------------------------------------------------------------------
                                                                       Sound source     Duration of installation
     Installation scenario          Foundation       Installation     level (dB re: 1    activity for a single
                                    installed           details       [mu]Pa at 1 m)              pile
----------------------------------------------------------------------------------------------------------------
Cofferdam Installation........  Sheet piles......  Vibratory pile    195 SEL RMS.....  60 minutes.
                                                    driving.
----------------------------------------------------------------------------------------------------------------

    Underwater noise associated with the construction of temporary 
cofferdams would only result from vibratory pile driving of steel sheet 
piles. As already described previously, Dominion Energy employed Tetra 
Tech to conduct the acoustic modeling to better understand the sound 
fields produced during these activities. These results also utilized 
information provided by iTAP (see Remmers and Bellmann (2021) 
Attachment Z-3 in Appendix A of Dominion Energy's application).
    Following a similar approach to the one described for foundation 
installation, Tetra Tech calculated the ranges to the defined acoustic 
thresholds using a maximum received level-over-depth approach where the 
maximum received sound level that occurs within the water column at 
each sampling point was used. Tetra Tech calculated both the 
Rmax and the R95 for each of the marine 
mammal regulatory thresholds. The results of this analysis are 
presented below in Table 17 and are presented in terms of the 
R95 range, based on the cofferdam modeling scenario 
found in Table 16 above. Given the nature of vibratory pile driving and 
the very small distances to Level A harassment thresholds (0-108 m; 
assuming 10 dB of sound attenuation), which accounts for one hour of 
vibratory pile driving per day, vibratory driving is not expected to 
result in Level A harassment. As Dominion Energy did not request any 
Level A harassment incidental to the installation and/or removal of 
sheet piles for temporary cofferdams, and based on these small 
distances, NMFS is not proposing to authorize any in this proposed 
action.

[[Page 28712]]



Table 17--Acoustic Ranges (R95%), in Meters, to Level A Harassment (PTS) and Level B Harassment Thresholds From Vibratory Pile Driving During Sheet Pile
                             Installation for Marine Mammal Function Hearing Groups, Assuming an Average Sound Speed Profile
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                       Distance to marine mammal thresholds
                                                                                        ----------------------------------------------------------------
                                                                                                    Level A harassment (PTS)                 Level B
                                                                                        ------------------------------------------------    harassment
               Activity                    Pile parameters           Approach used                                                          (behavior)
                                                                                          LFC (199    MFC (198    HFC (173     PP (201  ----------------
                                                                                            SEL)        SEL)        SEL)        SEL)       All (120 SPL
                                                                                                                                               RMS)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Temporary Cofferdams.................  2.8 m diameter Pin pile  Vibratory Pile Driving.         108           0           0           0            3,097
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: LFC = low-frequency cetaceans; MFC = mid-frequency cetaceans; HFC = high-frequency cetaceans; PP = phocid pinnipeds.

    dBSea was used to derive the acoustic ranges to the Level B 
harassment threshold, assuming no sound attenuation, around the cable 
landfall site. This included the ensonified area that was truncated by 
any land, which yielded an area (approximately 1 km\2\) smaller than 
the radius of a circle (assuming 3,097 m). For the vibratory pile 
driving for temporary cofferdams associated with the sheet pile 
installation and removal, the daily ensonified area was 29.04 km\2\ 
(11.21 mi\2\), based on the acoustic range to the Level B harassment 
threshold (3,097 m), with a total ensonified area of 4,980 km\2\ 
(1,922.8 mi\2\) over 54 days of installation.
    Density data from Roberts and Halpin (2022) were mapped within the 
boundary of the CVOW-C project area using geographic information system 
(GIS) software (Environmental Systems Research Institute (ESRI), 2017). 
To estimate marine mammal density around the temporary cofferdams, the 
greatest ensonified area was intersected with the density grid cells 
for each individual species to select all of those grid cells that the 
ensonified area intersects, representing the furthest extent where 
potential impacts to marine mammals could be expected. Maximum monthly 
densities (i.e., the maximum density found in each grid cell) were 
averaged by season (spring (May), summer (June through August), and 
fall (September through October)). Since the timing of landfall 
construction activities may vary somewhat from the proposed schedule, 
the highest average seasonal density from May through October (Dominion 
Energy's planned construction period for temporary cofferdams) for each 
species was selected and used to estimate exposures from temporary 
cofferdam installation and removal (Table 18).

Table 18--Highest Average Seasonal Marine Mammal Densities for Nearshore
  Trenchless Installation (Temporary Cofferdam and Temporary Goal Post
                        Installation) Activities
------------------------------------------------------------------------
                                                       Highest average
 Marine mammal hearing group                          seasonal density
         and species                  Stock            (individual/100
                                                           km\2\)
------------------------------------------------------------------------
LFC:
    North Atlantic right      Western North                        0.024
     whale *.                  Atlantic.
    Fin whale *.............  Western North                        0.041
                               Atlantic.
    Humpback whale..........  Gulf of Maine.......                 0.054
    Minke whale.............  Canadian East Coast.                 0.124
    Sei whale *.............  Nova Scotia.........                 0.015
MFC:
    Sperm whale *...........  North Atlantic......                 0.001
    Pygmy sperm whale.......  Western North                      \a\ n/a
                               Atlantic.
    Atlantic spotted dolphin  Western North                        2.370
                               Atlantic.
    Atlantic white-sided      Western North                        0.325
     dolphin.                  Atlantic.
    Bottlenose dolphin......  Southern Migratory                  17.054
                               Coastal.
    Clymene dolphin.........  Western North                      \a\ n/a
                               Atlantic.
    Common dolphin..........  Western North                        1.808
                               Atlantic.
    False killer whale......  Western North                      \a\ n/a
                               Atlantic.
    Melon-headed whale......  Western North                      \a\ n/a
                               Atlantic.
    Pilot whale spp.........  Western North                        0.065
                               Atlantic.
    Pantropical spotted       Western North                        0.007
     dolphin.                  Atlantic.
    Risso's dolphin.........  Western North                        0.030
                               Atlantic.
HFC:
    Harbor porpoise.........  Western North                        0.438
                               Atlantic.
PP:
    Gray seal...............  Western North                        1.775
                               Atlantic.
    Harbor seal.............  Western North                        1.775
                               Atlantic.
------------------------------------------------------------------------
Note: LFC = low-frequency cetaceans; MFC = mid-frequency cetaceans; HFC
  = high-frequency cetaceans; PP = phocid pinnipeds; * denotes species
  listed under the Endangered Species Act.
\a\ These species were added to the list of species that could be
  potentially impacted by the project after the adequate and complete
  date. However, given the rare occurrence of these species in the
  project area, proposed take was included only for foundation
  installation, and not for nearshore cable landfall activities.


[[Page 28713]]

    For some species where little density information is available 
(i.e., pilot whales), the annual density was used instead. Given 
overlap with the pinniped density models as the Roberts and Halpin 
(2022) dataset does not distinguish between some species, a collective 
``pinniped'' density was used for both harbor and gray seal species and 
later split for the take estimates and request (Roberts et al., 2016). 
This approach was the same as described in the WTG and OSS Foundation 
Installation section. Refer back to Table 18 for the densities used for 
temporary cofferdam installation and removal.
    Given that use of the vibratory hammer during cofferdam 
installation and removal may occur on up to six days per cofferdam 
(three days for installation and three days for removal), a max total 
of 54 days was assumed necessary for all nine cofferdams. To calculate 
exposures, the highest average seasonal marine mammal densities were 
multiplied by the daily ensonified area (29.04 km\2\) for installation 
and removal of sheet piles for temporary cofferdams. To yield the total 
estimated take for the activity, the per day take was multiplied by the 
ensonified area by the total number of days for the activity. To do 
this, the ensonified area was overlaid over the Roberts and Halpin 
(2022) densities to come up with a per day take which was then 
multiplied by 54 to account for the total number of days. This produced 
the results shown in Table 19. The product is then rounded, to generate 
an estimate of the total number of instances of harassment expected for 
each species over the duration of the work.
    Given the small distances to the Level A harassment isopleths, 
Level A harassment incidental to this activity is not anticipated, even 
absent mitigation, although mitigation measures are proposed that would 
further reduce the risk. Therefore, Dominion Energy is not requesting 
and NMFS is not proposing to authorize Level A harassment related to 
cofferdam installation and removal.
    Calculated take estimates for temporary cofferdams were then 
adjusted, for some species, based on group size characteristics known 
through the scientific literature and received sighting reports from 
previous projects and/or surveys. These group size estimates for 
cofferdam installation and removal are described below and were 
incorporated into the estimated take to yield the requested and 
proposed take estimate:
     Atlantic spotted dolphin: Adjusted based on 1 group size 
per day (20 per Dominion Energy, 2020, Jefferson et al., 2015);
     Bottlenose dolphin (Combined Southern Migratory Coastal, 
Western North Atlantic Offshore): Adjusted based on 1 group size per 
day (15 per Jefferson et al., 2015); and
     Common dolphin (short-beaked): Adjusted based on 1 group 
size per day (20 per Dominion Energy, 2021).
    Given that take by Level B harassment was precautionarily proposed 
for authorization during two years of foundation installation for 
Clymene dolphins, false killer whales, melon-headed whales, and pygmy 
sperm whales, and given the nearshore nature of cable landfall 
activities, no take (and therefore, no group size adjustments) have 
been accounted for nearshore cable landfall activities.
    Additionally, beyond group size adjustments, some slight 
modifications were performed for some species, including for harbor 
seals, gray seals, short- and long-finned pilot whales, and bottlenose 
dolphins. More specifically, the takes requested were accrued based on 
a 50/50 split for both pinniped species, as the Roberts and Halpin 
(2022) data does not differentiate the density by specific pinniped 
species. The density for pilot whales represents a single group 
(Globicephala spp.) and is not species-specific. Due to the minimal 
occurrence of both short-finned and long-finned pilot whales to occur 
in this area due to the shallow water, the requested take was allocated 
to a collective group, although short-finned pilot whales are more 
commonly seen in southern waters. Bottlenose dolphin stocks were split 
by the 20-m isobath cutoff, and then allocated specifically to the 
coastal stock of bottlenose dolphins (migratory southern coastal) due 
to the nearshore nature of these activities.
    Below we present the estimated take and maximum amount of take 
proposed for authorization during temporary cofferdam installation and 
removal during the proposed five-year effective period for the CVOW-C 
project (Table 19). No take by Level A harassment is expected, nor has 
it been requested by Dominion Energy or proposed for authorization by 
NMFS. The proposed take for authorization accounts for three days for 
installation and 3 days for removal, for a total of six days for each 
of nine cofferdams (54 days total). To be conservative, Dominion Energy 
has requested take, by Level B harassment, based on the highest 
exposures predicted by the density-based take estimates, with some 
slight modifications to account for group sizes for some species.
    Although North Atlantic right whales do migrate in coastal waters 
and have been seen off Virginia Beach, Virginia, they are not expected 
to occur in the nearshore waters where work would be occurring. The 
amount of work considered here is limited and would be conducted during 
a time when North Atlantic right whales are less likely to be migrating 
in this area. The distance to the Level B harassment isopleth (3.1 km) 
for installation and removal of the sheet piles associated with the 
cofferdams and the maximum distance to the Level A isopleth (0.11 km) 
remain in shallow waters in the nearshore environment and for a very 
short period of time (approximately one hour daily); thus, it is 
unlikely that right whales (or most species of marine mammals 
considered here) would be exposed to vibratory pile driving during 
cofferdam installation and removal at levels close to the 120 dB Level 
B harassment threshold or to the Level A harassment thresholds. Hence, 
Dominion Energy did not request take of North Atlantic right whales 
incidental to this activity and NMFS is not proposing to authorize it.
    We note that these would be the maximum number of animals that may 
be harassed during vibratory pile driving for nearshore temporary 
cofferdams as the analysis conservatively assumes each exposure is a 
different animal. This is unlikely to be the case for all species shown 
here but is the most comprehensive assessment of the level of impact 
from this activity.

[[Page 28714]]



  Table 19--Density-Based Estimated and Maximum Amount of Take Proposed for Authorization by Level B Harassment
            From Vibratory Pile Driving Associated With Temporary Cofferdam Installation and Removal
----------------------------------------------------------------------------------------------------------------
                                                                                                 Takes of marine
                                                                                 Density-based  mammals proposed
  Marine mammal hearing group and species                  Stock                estimated take         for
                                                                                                  authorization
----------------------------------------------------------------------------------------------------------------
                                                            Level B harassment
----------------------------------------------------------------------------------------------------------------
LFC:
    North Atlantic right whale *..........  Western North Atlantic............           0.376                 0
    Fin whale *...........................  Western North Atlantic............           0.643                 1
    Humpback whale........................  Gulf of Maine.....................           0.847                 1
    Minke whale...........................  Canadian East Coast...............           1.945                 2
    Sei whale *...........................  Nova Scotia.......................           0.235                 0
MFC:
    Sperm whale *.........................  North Atlantic....................           0.016                 0
    Pygmy sperm whale.....................  Western North Atlantic............         \d\ n/a           \d\ n/a
    Atlantic spotted dolphin..............  Western North Atlantic............          37.169               240
    Atlantic white-sided dolphin \c\......  Western North Atlantic............           5.097                 5
    Bottlenose dolphin....................  Southern Migratory Coastal........         267.462               180
                                            Western North Atlantic, Offshore..         \a\ n/a           \a\ n/a
    Clymene dolphin.......................  Western North Atlantic............         \d\ n/a           \d\ n/a
    Common dolphin........................  Western North Atlantic............          28.355               240
    False killer whale....................  Western North Atlantic............         \d\ n/a           \d\ n/a
    Melon-headed whale....................  Western North Atlantic............         \d\ n/a           \d\ n/a
    Pilot whale spp.......................  Western North Atlantic............           1.019                 1
    Pantropical spotted dolphin...........  Western North Atlantic............           0.110                 0
    Risso's dolphin.......................  Western North Atlantic............           0.470                 0
HFC:
    Harbor porpoise.......................  Western North Atlantic............           6.869                 7
PP:
    Gray seal \b\.........................  Western North Atlantic............          13.919                14
    Harbor seal \b\.......................  Western North Atlantic............          13.919                14
----------------------------------------------------------------------------------------------------------------
Note: LFC = low-frequency cetaceans; MFC = mid-frequency cetaceans; HFC = high-frequency cetaceans; PP = phocid
  pinnipeds; * denotes species listed under the Endangered Species Act.
\a\ Given cofferdam installation and removal would be confined to an area below the 20-m isobath, all of the
  estimated take has been allocated to the coastal stock.
\b\ The take request for pinnipeds was allocated to an even 50 percent split to each harbor seal and gray seal.
\c\ Atlantic white-sided dolphins are not expected, but due to shifts in habitat use, have been included in the
  take request based on a standard group size annually. We note that animat/exposure modeling was not done for
  this species.
\d\ Given take by Level B harassment was precautionarily proposed for authorization during two years of
  foundation installation for these species, no take has been calculated for cable landfall construction
  activities.

Temporary Goal Posts
    To facilitate nearshore, trenchless installation for the export 
cables to shore, Direct Steerable Pipe Tunneling equipment utilizing a 
steerable tunnel boring machine would excavate ground while goal posts 
are used to guide steel casing pipes behind the tunnel boring machine 
using a pipe thruster. Of all the equipment planned for use during the 
tunneling and boring activities (i.e., pipe thrusting machine, pumps, 
motors, powerpacks, and drill mud processing system), only the impact 
hammer is expected to cause harassment to marine mammals as other 
equipment either produces low source levels. The pipe thrusting machine 
does not vibrate or produce any noise as it only pushes the casing 
pipes so no harassment to marine mammals is expected to occur from the 
use of this equipment. Each temporary goal post, which would be 
installed via impact pile driving, would consist of 1.07 m (42 in) 
diameter steel pipe piles. Up to two steel pipes could be installed per 
day for a total duration of 130 minutes per goal post. The strike rate 
would require approximately 260 strikes per pile with a strike duration 
between 0.5 and 2 seconds. Up to 12 goal posts would be needed for each 
of the nine Direct Pipe (temporary cofferdam) locations, equating to a 
total of 108 piles necessary for the goal posts. Removal of the pipe 
piles would occur at a rate of 2 per day over 54 days to remove all 108 
piles. Unlike installation, removal of pipe piles is not expected to 
cause take of marine mammals as mechanical and/or hydraulic equipment 
is used that does not produce noise. Because of this, the analysis 
described below only pertains to the installation of goal posts.
    Tetra Tech applied the Level A harassment cumulative PTS criteria 
to a specific tab (for impact pile driving) spreadsheet (called the 
User Spreadsheet) that reflects NOAA Fisheries' 2018 Revisions to 
Technical Guidance (NOAA Fisheries, 2018a). The User Spreadsheet relies 
on overriding default values, calculating individual adjustment 
factors, and using the difference between levels with and without 
weighting functions for each of the five categories of hearing groups. 
The new adjustment factors in the spreadsheets allow for the 
calculation of cumulative sound exposure level (SELcum) 
distances and peak sound exposure (PK) distances and account for the 
accumulation (Safe Distance Methodology) using the source 
characteristics (duty cycle and speed) after Silve et al. (2014).
    To calculate the distance to the acoustic threshold for Level B 
harassment of marine mammals, Tetra Tech utilizing a spread calculation 
to estimate the horizontal distance to the 160 dB re 1 [mu]Pa isopleth:

SPL(r) = SL-PL(r)

Where:

SPL = sound pressure level (dB re 1 [mu]Pa);

[[Page 28715]]

r = range (m), SL = source level (dB re 1 [mu]Pa m); and
PL = propagation loss as a function of distance (calculated as 
20Log10(r)).

    We note that while these methodologies provided by NOAA Fisheries 
are able to calculate the maximum distances to the Level A harassment 
and Level B harassment thresholds, these calculations do not allow for 
the inclusion of site-specific environmental parameters, as was 
described for activities analyzed through dBSea.
    The results of this analysis are presented below in Table 20 and 
are presented in terms of the R95 range. Table 20 
demonstrates the maximum distances to both the regulatory thresholds 
for Level A harassment and Level B harassment for each marine mammal 
hearing group. Given the very small distances to the Level A harassment 
thresholds (4.5-152 m; assuming 10 dB of sound attenuation), which 
accounts for 130 minutes (approximately 2.2 hours) of impact pile 
driving per day, impact driving is not expected to result in Level A 
harassment. As Dominion Energy did not request any Level A harassment 
incidental to the installation and/or removal of steel pipe piles for 
temporary goal posts, and based on these small distances, NMFS is not 
proposing to authorize any in this proposed action.

 Table 20--Ranges, in Meters, to Level A Harassment (PTS) and Level B Harassment Thresholds From Impact Pile Driving During Steel Pipe Pile Installation
                                                 of Goal Posts for Marine Mammal Function Hearing Groups
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                Distance to marine mammal thresholds (in meters)
                                                                                       -----------------------------------------------------------------
                                                                                                  Level A harassment (PTS onset)               Level B
                                                                                       ----------------------------------------------------  harassment
              Activity                    Pile parameters           Approach used                                                           (behavioral)
                                                                                        LFC (183 dB  MFC (185 dB  HFC (155 dB   PP (185 dB -------------
                                                                                          SELcum)      SELcum)      SELcum)      SELcum)     All (160 dB
                                                                                                                                                RMS)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Temporary Goal Posts................  1.07 m diameter Steel    Impact Pile Driving....        590.9         21.0        703.8        316.2         1,450
                                       Pipe Piles.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: LFC = low-frequency cetaceans; MFC = mid-frequency cetaceans; HFC = high-frequency cetaceans; PP = phocid pinnipeds.

    Given the small distances to Level A harassment isopleths, Level A 
harassment incidental to this activity is not anticipated, even absent 
mitigation, although mitigation measures are proposed that would 
further reduce the risk. Therefore, Dominion Energy is not requesting 
and NMFS is not proposing to authorize Level A harassment related to 
goal post installation. The acoustic ranges to the Level B harassment 
threshold, assuming no sound attenuation, were used to calculate the 
ensonified area around the cable landfall site. The Ensonified Area is 
calculated as the following:

Ensonified Area = pi x r2,

Where:

r is the linear acoustic range distance from the source to the 
isopleth to the Level B harassment thresholds.

    To accurately account for the greatest level of impact (via 
behavioral harassment) to marine mammals, Tetra Tech applied the 
evaluated maximum Level B harassment distance (1,450 m) as the basis 
for determining potential takes. To get an accurate value of the total 
ensonified area within the aquatic environment, the isopleth was 
overlaid on a map to determine if any truncation by land would occur 
due to the nearshore proximity of the goal posts. For the vibratory 
pile driving for temporary cofferdams associated with the sheet pile 
installation and removal, it was assumed that the daily ensonified area 
was 4.98 km\2\ (1.92 mi\2\), or a total ensonified area of 268.92 km\2\ 
(103.83 mi\2\) over 54 days of installation and removal. The daily 
ensonified area that resulted from this analysis (4.98 km\2\) was 
carried forward into the take estimates as the daily ensonified area.
    In the same approach as was undertaken by the temporary cofferdams, 
the greatest ensonified area was intersected with the density grid 
cells for each individual species to select all of those grid cells 
that the ensonified area intersects to estimate the marine mammal 
density relevant to the temporary goal posts. Maximum monthly densities 
(i.e., the maximum density found in each grid cell) were averaged by 
season. Since the timing of landfall construction activities may vary 
somewhat from the proposed schedule, the highest average seasonal 
density from May through October (Dominion Energy's planned 
construction period for temporary goal posts) for each species was 
selected and used to estimate exposures from temporary goal post 
installation. For some species where little density information is 
available (i.e., pilot whale spp, pantropical spotted dolphins), the 
annual density was used instead. Given overlap with the pinniped 
density models as the Roberts and Halpin (2022) dataset does not 
distinguish between some species, a collective ``pinniped'' density was 
used for both harbor and gray seal species and later split for the take 
estimates and request (Roberts et al., 2016). This approach was the 
same as described in the temporary cofferdams. Furthermore, given the 
densities are the same as what was calculated for temporary cofferdams, 
we reference the reader back to Table 18 above.
    To calculate exposures, the highest average seasonal marine mammal 
densities from Table 18 were multiplied by the daily ensonified area 
(4.98 km\2\) for installation and removal of steel pipe piles for 
temporary goal posts. Given that use of the impact hammer during goal 
post installation may occur at a rate of 2 pipe piles per day for a 
total of 54 days (based on 108 total steel pipe piles), the daily 
estimated take was multiplied by 54 to produce the results shown in 
Table 21. The product is then rounded, to generate an estimate of the 
total number of instances of harassment expected for each species over 
the duration of the work. Again, as previously noted, no take was 
calculated for the removal of goal posts due to the equipment planned 
for use.
    The take estimates for Level B harassment related to temporary goal 
post installation were then adjusted, for some species, based on group 
size characteristics known through the scientific literature and 
received sighting reports from previous projects and/or surveys. These 
group size estimates for temporary goal post installation are described 
below and

[[Page 28716]]

were incorporated into the estimated take to yield the requested and 
proposed take estimate:
     Atlantic spotted dolphin: Adjusted based on 1 group size 
per day (20 per Dominion Energy, 2020; Jefferson et al., 2015);
     Bottlenose dolphin (Southern Migratory Coastal Stock): 
Adjusted based on 1 group size per day (15 per Jefferson et al., 2015); 
and
     Short-beaked common dolphin: Adjusted based on 1 group 
size per day (20 per Dominion Energy, 2021).
    Given that take by Level B harassment was precautionarily proposed 
for authorization during two years of foundation installation for 
Clymene dolphins, false killer whales, melon-headed whales, and pygmy 
sperm whales, and given the nearshore nature of cable landfall 
activities, no take (and therefore, no group size adjustments) have 
been accounted for nearshore cable landfall activities.
    Additionally, beyond group size adjustments, some slight 
modifications were performed for some species, including for harbor 
seals, gray seals, short- and long-finned pilot whales, and bottlenose 
dolphins. More specifically, the takes requested were accrued based on 
a 50/50 split for both pinniped species, as the Roberts and Halpin 
(2022) data does not differentiate the density by specific pinniped 
species. The density for pilot whales represents a single group 
(Globicephala spp.) and is not species-specific. Due to the occurrence 
of both short-finned and long-finned pilot whales to occur in this 
area, the requested take was allocated to a collective group, although 
short-finned pilot whales are commonly seen in southern waters. 
Bottlenose dolphin stocks were split by the 20-m isobath cutoff, and 
then allocated specifically to the coastal stock of bottlenose dolphins 
(migratory southern coastal) due to the nearshore nature of these 
activities. Lastly, due to the size of the Level B harassment isopleth 
(1,450 m), Dominion Energy has proposed a 1,500 m (1,640.4 ft) shutdown 
zone to exceed this distance. However, given the proximity to land, 
large whales are not anticipated to occur this close to nearshore 
activities. Because of the proposed mitigation zone and the nearshore 
location of the temporary goal posts, Dominion Energy has requested, 
and NMFS has proposed, to adjust the proposed takes for large whales 
(i.e., mysticetes and sperm whales) to zero.
    Below we present the estimated take and maximum amount of take 
proposed for authorization during temporary goal post installation 
during the proposed five-year effective period for the CVOW-C project 
(Table 21). No take by Level A harassment is expected, nor has it been 
requested by Dominion Energy or proposed for authorization by NMFS. 
These proposed take estimates take into account 54 days total for 
temporary goal post activities, including installation and removal, at 
a rate of 2 steel pipe piles installed per day over 130 minutes.

   Table 21--Density-Based Estimated and Maximum Amount of Take by Level B Harassment From Impact Pile Driving
                                Associated With Temporary Goal Post Installation
----------------------------------------------------------------------------------------------------------------
                                                                                                 Requested take
 Marine mammal hearing group and species                 Stock                  Density-based       of marine
                                                                               estimated take        mammals
----------------------------------------------------------------------------------------------------------------
                                                            Level B harassment
----------------------------------------------------------------------------------------------------------------
LFC:
    North Atlantic right whale *.........  Western North Atlantic...........             0.065                 0
    Fin whale *..........................  Western North Atlantic...........             0.110                 0
    Humpback whale.......................  Gulf of Maine....................             0.145                 0
    Minke whale..........................  Canadian East Coast..............             0.333                 0
    Sei whale *..........................  Nova Scotia......................             0.040                 0
MFC:
    Sperm whale *........................  North Atlantic...................             0.003                 0
    Pygmy sperm whale....................  Western North Atlantic...........           \d\ n/a           \d\ n/a
    Atlantic spotted dolphin.............  Western North Atlantic...........             6.373               360
    Atlantic white-sided dolphin \c\.....  Western North Atlantic...........             0.874                 1
    Bottlenose dolphin...................  Southern Migratory Coastal.......            45.862               270
                                           Western North Atlantic, Offshore.           \a\ n/a           \a\ n/a
    Clymene dolphin......................  Western North Atlantic...........           \d\ n/a           \d\ n/a
    Common dolphin.......................  Western North Atlantic...........             4.862               360
    False killer whale...................  Western North Atlantic...........           \d\ n/a           \d\ n/a
    Melon-headed whale...................  Western North Atlantic...........           \d\ n/a           \d\ n/a
    Pilot whale spp......................  Western North Atlantic...........             0.175                 0
    Pantropical spotted dolphin..........  Western North Atlantic...........             0.019                 0
    Risso's dolphin......................  Western North Atlantic...........             0.081                 0
HFC:
    Harbor porpoise......................  Western North Atlantic...........             1.178                 1
PP:
    Gray seal \b\........................  Western North Atlantic...........             2.387                 2
    Harbor seal \b\......................  Western North Atlantic...........             2.387                 2
----------------------------------------------------------------------------------------------------------------
Note: LFC = low-frequency cetaceans; MFC = mid-frequency cetaceans; HFC = high-frequency cetaceans; PP = phocid
  pinnipeds; * denotes species listed under the Endangered Species Act.
\a\ Given temporary goal post installation would be confined to an area below the 20-m isobath, all of the
  estimated take has been allocated to the coastal stock.
\b\ The take request for pinnipeds was allocated to an even 50 percent split to each harbor seal and gray seal.
\c\ Atlantic white-sided dolphins are not expected, but due to shifts in habitat use, have been included in the
  take request based on a standard group size annually. We note that animat/exposure modeling was not done for
  this species.
\d\ Given take by Level B harassment was precautionarily proposed for authorization during two years of
  foundation installation for these species, no take has been calculated for cable landfall construction
  activities.


[[Page 28717]]

    We note that these would be the maximum number of animals that may 
be harassed during impact pile driving for nearshore temporary goal 
posts as the analysis conservatively assumes each exposure is a 
different animal. This is unlikely to be the case for all species shown 
here but is the most comprehensive assessment of the level of impact 
from this activity.

HRG Surveys

    Dominion Energy's proposed HRG survey activities includes the use 
of impulsive (i.e., boomers and sparkers) and non-impulsive (i.e., 
CHIRP SBPs) sources. Refer back to Table 4 for a representative list of 
the acoustic sources and their operational parameters. Authorized takes 
would be by Level B harassment only, in the form of disruption of 
behavioral patterns for individual marine mammals resulting from 
exposure to noise from certain HRG acoustic sources. Based primarily on 
the characteristics of the signals produced by the acoustic sources 
planned for use, Level A harassment is neither anticipated, even absent 
mitigation, nor proposed to be authorized. Consideration of the 
anticipated effectiveness of the mitigation measures (i.e., pre-start 
clearance and shutdown measures), discussed in detail below in the 
Proposed Mitigation section, further strengthens the conclusion that 
Level A harassment is not a reasonably expected outcome of the survey 
activity. Therefore, the potential for Level A harassment is not 
evaluated further in this document. Dominion Energy did not request, 
and NMFS is not proposing to authorize, take by Level A harassment 
incidental to HRG surveys. Please see Dominion Energy's application for 
the CVOW-C project for details of a quantitative exposure analysis 
(i.e., calculated distances to Level A harassment isopleths and Level A 
harassment exposures). No serious injury or mortality is anticipated to 
result from HRG survey activities.
    Specific to HRG surveys, in order to better consider the narrower 
and directional beams of the sources, NMFS has developed a tool for 
determining the sound pressure level (SPLrms) at the 160-dB 
isopleth for the purposes of estimating the extent of Level B 
harassment isopleths associated with HRG survey equipment (NMFS, 2020). 
This methodology incorporates frequency-dependent absorption and some 
directionality to refine estimated ensonified zones. Tetra Tech used 
NMFS' methodology with additional modifications to incorporate a 
seawater absorption formula and account for energy emitted outside of 
the primary beam of the source. For sources that operate with different 
beamwidths, the maximum beam width was used, and the lowest frequency 
of the source was used when calculating the frequency-dependent 
absorption coefficient (see Table 4).
    NMFS considers the data provided by Crocker and Fratantonio (2016) 
to represent the best available information on source levels associated 
with HRG equipment and, therefore, recommends that source levels 
provided by Crocker and Fratantonio (2016) be incorporated in the 
method described above to estimate ranges to the Level A harassment and 
Level B harassment isopleths. In cases when the source level for a 
specific type of HRG equipment is not provided in Crocker and 
Fratantonio (2016), NMFS recommends that either the source levels 
provided by the manufacturer be used, or, in instances where source 
levels provided by the manufacturer are unavailable or unreliable, a 
proxy from Crocker and Fratantonio (2016) be used instead. Tetra Tech 
utilized the following criteria for selecting the appropriate inputs 
into the NMFS User Spreadsheet Tool (NMFS, 2018):
    (1) For equipment that was measured in Crocker and Fratantonio 
(2016), the reported source level for the most likely operational 
parameters was selected.
    (2) For equipment not measured in Crocker and Fratantonio (2016), 
the best available manufacturer specifications were selected. Use of 
manufacturer specifications represent the absolute maximum output of 
any source and do not adequately represent the operational source. 
Therefore, they should be considered an overestimate of the sound 
propagation range for that equipment.
    (3) For equipment that was not measured in Crocker and Fratantonio 
(2016) and did not have sufficient manufacturer information, the 
closest proxy source measured in Crocker and Fratantonio (2016) was 
used.
    The Dura-spark measurements and specifications provided in Crocker 
and Fratantonio (2016) were used for all sparker systems proposed for 
the HRG surveys. These included variants of the Dura-spark sparker 
system and various configurations of the GeoMarine Geo-Source sparker 
system. The data provided in Crocker and Fratantonio (2016) represent 
the most applicable data for similar sparker systems with comparable 
operating methods and settings when manufacturer or other reliable 
measurements are not available. Crocker and Fratantonio (2016) provide 
S-Boom measurements using two different power sources (CSP-D700 and 
CSP-N). The CSP-D700 power source was used in the 700 joules (J) 
measurements but not in the 1,000 J measurements. The CSP-N source was 
measured for both 700 J and 1,000 J operations but resulted in a lower 
source level; therefore, the single maximum source level value was used 
for both operational levels of the S-Boom.
    Table 22 identifies all the representative survey equipment that 
operates below 180 kHz (i.e., at frequencies that are audible and have 
the potential to disturb marine mammals) that may be used in support of 
planned survey activities, and are likely to be detected by marine 
mammals given the source level, frequency, and beamwidth of the 
equipment. This table also provides all operating parameters used to 
calculate the distances to threshold for marine mammals.

   Table 22--Summary of Representative HRG Survey Equipment With Operating Parameters To Calculate Harassment
                                          Distances for Marine Mammals
----------------------------------------------------------------------------------------------------------------
                                                                                                   Source level
                                                                                     Operating    (SLRMS) (dB re
          Equipment classification                     Survey equipment              frequency       1[mu]Pa)
                                                                                       (kHz)
----------------------------------------------------------------------------------------------------------------
Multibeam Echosounder......................  R2Sonics 2026......................         170-450             191
Synthetic Aperture Sonar, combined           Kraken Aquapix \a\.................             337             N/A
 bathymetric/sidescan.
Sidescan Sonar.............................  Edgetech 4200 dual frequency \a\...     300 and 600             N/A
Parametric SBP.............................  Innomar SES-2000 Medium 100........            2-22             241
Non-Parametric SBP.........................  Edgetech 216 CHIRP.................            2-16             193
                                             Edgetech 512 CHIRP.................          0.5-12             177

[[Page 28718]]

 
Medium Penetration SBP.....................  GeoMarine Dual 400 Sparker 800 J...          0.25-4             200
                                             Applied Acoustics S-Boom (Triple            0.5-3.5             203
                                              Plate Boomer 1000 J).
----------------------------------------------------------------------------------------------------------------
Note: dB re 1 [mu]Pa m--decibels referenced to 1 MicroPascal at 1 meter; kHz--kilohertz.
\a\ Operating frequencies are above marine mammal hearing thresholds.

    Results of modeling using the methodology described above indicated 
that, of the HRG equipment planned for use by Dominion Energy that has 
the potential to result in Level B harassment of marine mammals, sound 
produced by the GeoMarine Dual 400 sparker would propagate furthest to 
the Level B harassment isopleth (100 m (328 ft); Table 23). For the 
purposes of take estimation, it was conservatively assumed that sparker 
would be the dominant acoustic source for all survey days (although, 
again, this may not always be the case). Thus, the range to the 
isopleth corresponding to the threshold for Level B harassment for and 
the boomer and sparkers (100 m) was used as the basis of take 
calculations for all marine mammals. This is a conservative approach, 
as the actual sources used on individual survey days, or during a 
portion of a survey day, may produce smaller distances to the Level B 
harassment isopleth.

  Table 23--Summary of Representative HRG Survey Equipment Distances to
                    the Level B Harassment Threshold
------------------------------------------------------------------------
                                                           Distance (m)
                                                            to Level B
    Equipment classification         Survey equipment       harassment
                                                             threshold
------------------------------------------------------------------------
Multibeam Echosounder..........  R2Sonics 2026..........             0.3
Synthetic Aperture Sonar,        Kraken Aquapix \a\.....             N/A
 combined bathymetric/sidescan.
Sidescan Sonar.................  Edgetech 4200 dual                  N/A
                                  frequency \a\.
Parametric SBP.................  Innomar SES-2000 Medium             0.7
                                  100.
Non-Parametric SBP.............  Edgetech 216 CHIRP.....            10.2
                                 Edgetech 512 CHIRP.....             2.4
Medium Penetration SBP.........  GeoMarine Dual 400                100.0
                                  Sparker 800 J.
                                 Applied Acoustics S-               21.9
                                  Boom (Triple Plate
                                  Boomer 1000 J).
------------------------------------------------------------------------
Note: dB re 1 [micro]Pa m--decibels referenced to 1 MicroPascal at 1
  meter; kHz--kilohertz
\a\ Operating frequencies are above marine mammal hearing thresholds.

    To estimate densities for the HRG surveys occurring both within the 
Lease Area and within the Export Cable Routes for the CVOW-C project 
based on the Roberts and Halpin (2022) dataset the relevant density 
models using GIS (ESRI, 2017) were overlaid to the CVOW-C project and 
survey area. The boundary of the CVOW-C HRG project area corresponds to 
the Lease Area and Export Cable Routes, for which the area was not 
increased due to an additional perimeter, as was done for foundation 
installation. For each survey segment, the average densities (i.e., the 
average density of each grid cell) was averaged by season over the 
survey duration (spring, summer, fall, and winter) for the entire HRG 
survey area. The average seasonal density within the HRG survey area 
was then selected for inclusion into the take calculations. Refer to 
Table 25 for the densities used for HRG surveys.
    As previously stated, of the HRG equipment planned for use by 
Dominion Energy that has the potential to result in Level B harassment 
of marine mammals, sound produced by the GeoMarine Dual 400 sparker 
would propagate furthest to the Level B harassment isopleth (100 m). 
This maximum range to the Level B harassment threshold and the 
estimated trackline distance traveled per day by a given survey vessel 
(i.e., 58 km (36 mi); Table 24), assuming a travel speed of 1.3 kts 
(1.49 miles per hour), were then used to calculate the daily ensonified 
area, or zone of influence (ZOI) around the survey vessel.

   Table 24--Survey Durations and Daily/Annual Trackline Distances Planned To Occur During the Proposed CVOW-C
                                                     Project
----------------------------------------------------------------------------------------------------------------
                                                                     Number of       Estimated
            Survey year                     Survey segment         active survey   distances per    Annual line
                                                                    vessel days      day (km)       kilometers
----------------------------------------------------------------------------------------------------------------
2024...............................  Pre-lay surveys............              65                           3,770
2025...............................  As-built surveys and pre-               249                          14,442
                                      lay surveys.
2026...............................  As-built surveys...........              58              58           3,364
2027...............................  Post-construction surveys..             368                          21,344

[[Page 28719]]

 
2028...............................  Post-construction surveys..             368                          21,344
----------------------------------------------------------------------------------------------------------------

    The ZOI is a representation of the maximum extent of the ensonified 
area around a HRG sound source over a 24-hr period. The ZOI for each 
piece of equipment operating at or below 180 kHz was calculated per the 
following formula:

Mobile Source ZOI = (Distance/day x 2r) + pi x r\2\

Where:

Distance/day is the maximum distance a survey vessel could travel in 
a 24-hour period; and
r is the linear distance from the source to the harassment 
threshold.

    The largest daily ZOI (111.6 km\2\ (4.48 mi\2\)), associated with 
the proposed use of the sparker, was applied to all planned survey 
days.
    As previously described, this assumes a total length of surveys 
that will occur within the CVOW-C project area as 64,264 km\2\ 
(24,812.5 mi\2\). As Dominion Energy is not sure of the exact 
geographic locations of the survey effort, these values cannot 
discreetly be broken up between the Lease Area and the Export Cable 
Routes. However, the values presented in Table 24 provide a 
comprehensive accounting of the total annual survey effort anticipated 
to occur.
    For HRG surveys, density data from Roberts and Halpin (2022) were 
mapped within the boundary of the CVOW-C project area using GIS 
software (ESRI, 2017). The boundary of the CVOW-C HRG project area 
corresponds to the Lease Area and Export Cable Routes, for which the 
area was not increased due to an additional perimeter, as was done for 
foundation installation. For each survey segment, the average densities 
(i.e., the average density of each grid cell) was averaged by season 
over the survey duration (spring, summer, fall, and winter) for the 
entire HRG survey area. The average seasonal density within the HRG 
survey area was then selected for inclusion into the take calculations. 
The potential Level B density-based harassment exposures are estimated 
by multiplying the average seasonal density of each species within the 
survey area by the daily ZOI. That product was then multiplied by the 
number of planned survey days in each sector during the approximately 
5-year construction timeframe (refer back to Table 5 and 24) and the 
product was rounded to the nearest whole number. As described above, 
this is a conservative estimate as it assumes the HRG source that 
results in the greatest isopleth distance to the Level B harassment 
threshold would be operated at all times during the entire survey, 
which may not ultimately occur. These density values are found in Table 
25.

   Table 25--Highest Average Seasonal Marine Mammal Densities for HRG
                            Survey Activities
------------------------------------------------------------------------
                                                       Highest average
 Marine mammal hearing group                          seasonal density
         and species                  Stock           (individual/ 100
                                                           km\2\)
------------------------------------------------------------------------
LFC:
North Atlantic right whale *  Western North                        0.095
                               Atlantic.
    Fin whale *.............  Western North                        0.080
                               Atlantic.
    Humpback whale..........  Gulf of Maine.......                 0.103
    Minke whale.............  Canadian East Coast.                 0.344
    Sei whale *.............  Nova Scotia.........                 0.038
MFC:
    Sperm whale *...........  North Atlantic......                 0.002
    Pygmy sperm whale.......  Western North                      \a\ n/a
                               Atlantic.
    Atlantic spotted dolphin  Western North                        4.649
                               Atlantic.
    Atlantic white-sided      Western North                        0.678
     dolphin.                  Atlantic.
    Bottlenose dolphin......  Combined Southern                   24.157
                               Migratory Coastal,
                               Western North
                               Atlantic Offshore.
    Clymene dolphin.........  Western North                      \a\ n/a
                               Atlantic.
    Common dolphin..........  Western North                        6.599
                               Atlantic.
    False killer whale......  Western North                      \a\ n/a
                               Atlantic.
    Melon-headed whale......  Western North                      \a\ n/a
                               Atlantic.
    Pilot whale spp.........  Western North                        0.065
                               Atlantic.
    Pantropical spotted       Western North                        0.007
     dolphin.                  Atlantic.
    Risso's dolphin.........  Western North                        0.057
                               Atlantic.
HFC:
    Harbor porpoise.........  Western North                        1.477
                               Atlantic.
PP:
    Gray seal...............  Western North                        5.402
                               Atlantic.
    Harbor seal.............  Western North                        5.402
                               Atlantic.
------------------------------------------------------------------------
Note: LFC = low-frequency cetaceans; MFC = mid-frequency cetaceans; HFC
  = high-frequency cetaceans; PP = phocid pinnipeds; * denotes species
  listed under the Endangered Species Act.
\a\ This species was incorporated after the animat analysis was
  completed so no take was estimated. Instead, a standard group size of
  animals was used instead for any analysis pertaining to this species.


[[Page 28720]]

    For most species or species groups, monthly densities are 
available, though in some cases insufficient data are available or we 
are unable to differentiate species groups by individual genus (e.g., 
gray and harbor seals). In these situations, additional adjustments are 
necessary and are described here. For pinnipeds, the density values 
derived from the Roberts and Halpin (2022) data were considered 
unrealistic given a reduced summer occurrence near the CVOW-C project 
area in the summer (Hayes et al., 2021). Based on information found in 
Hayes et al. (2021), a conservative density estimate of 0.00001 
animals/km\2\ was used to represent the summer density of both pinniped 
species within the modeled CVOW-C project area and Lease Area plus the 
8.9 km perimeter. Any take by Level B harassment derived from these 
densities would be further split by an even percentage (50/50) for each 
species. For bottlenose dolphins, due to specific environmental 
characteristics that were used to partition the Southern Migratory 
Coastal and Western North Atlantic Offshore stocks, both the coastal 
and the offshore stocks were divided based on the location of the 20-m 
isobath. Information by Hayes et al. (2021) indicates a boundary 
between the two stocks at the 20-m isobath located north of Cape 
Hatteras, North Carolina. Therefore, all bottlenose dolphins whose grid 
cells were less than the 20-m isobath in the CVOW-C modeling area or 
within the 8.9 km of the Lease Area were allocated to the Southern 
Migratory Coastal stock. All density grid cells greater than the 20-m 
isobath from the CVOW-C modeling area or within the 8.9 km of the Lease 
Area were allocated to the offshore stock. The number of marine mammals 
expected to be incidentally taken per day is then calculated by 
estimating the number of each species predicted to occur within the 
daily ensonified area (animals/km\2\), incorporating the maximum 
seasonal estimated marine mammal densities as described above. 
Estimated numbers of each species taken per day across all survey sites 
are then multiplied by the total number of survey days annually. The 
product is then rounded, to generate an estimate of the total number of 
instances of harassment expected for each species over the duration of 
the survey. A summary of this method is illustrated in the following 
formula:

Estimated Take = D x ZOI x # of days

Where:

D is the average seasonal density for each species; and
ZOI is the maximum daily ensonified area to the harassment 
threshold.

    The take estimates were then adjusted, for some species, based on 
group size and sighting reports from previous projects and/or surveys. 
These group size estimates for HRG surveys are described below and were 
incorporated into the estimated take to yield the requested and 
proposed take estimate:
     Atlantic white-sided dolphin: Adjusted based on 1 group 
size per year (15 per Reeves et al., 2002);
     Risso's dolphin: Adjusted based on 1 group size per year 
(25 per Dominion Energy, 2021; Jefferson et al., 2015);
     Bottlenose dolphin (Combined Southern Migratory Coastal, 
Western North Atlantic Offshore): Adjusted based on 1 group size per 
day (15 per Jefferson et al., 2015);
     Pantropical spotted dolphins: Adjusted based on 1 group 
size per day (20 individuals);
     Common dolphins: Adjusted based on 1 group size per day 
(20 individuals);
     Common dolphins: Adjusted based on 1 group size per year 
(20 individuals); and
     Pilot whale spp.: Adjusted based on 1 group size per year 
(20 individuals).
    Given the very small zone sizes associated with HRG surveys, no 
take in addition to that requested, and proposed to be authorized, for 
foundation installation (which has much larger sizes) is proposed to be 
authorized for the following species: false killer whales, melon-headed 
whales, and pygmy sperm whales. Clymene dolphins are from the Stenella 
sp. so shutdown would be waived for this species given their prevalence 
to bow-ride. Because of this, no take (and therefore, no group size 
adjustments) have been accounted for these species from HRG survey 
activities.
    Similar to other activities, the density-based exposure estimates 
were adjusted due to the manner in which density data is presented in 
the Duke models for harbor seals, gray seals, short- and long-finned 
pilot whales, and bottlenose dolphins. More specifically, the takes 
requested were split 50/50 for both pinniped species, as the Roberts 
and Halpin (2022) data does not differentiate the density by specific 
pinniped species. The density for pilot whales represents a single 
group (Globicephala spp.) and is not species-specific. Due to the 
occurrence of both short-finned and long-finned pilot whales to occur 
in this area, the requested take was allocated to a collective group, 
although short-finned pilot whales are commonly seen in southern 
waters. Due to an inability to spatial resolution at the current state 
of the survey planning, bottlenose dolphin stocks were combined into a 
single group for both the coastal stock of bottlenose dolphins 
(Migratory Southern Coastal) and the offshore stock (Western North 
Atlantic Offshore).
    Below we present the maximum amount of take proposed for 
authorization during HRG surveys occurring during the proposed five-
year effective period for the CVOW-C project (Table 26). No take by 
Level A harassment is expected, nor has it been requested by Dominion 
Energy or proposed for authorization by NMFS. We note that these would 
be the maximum number of animals that may be harassed during HRG 
surveys as the analysis conservatively assumes each exposure is a 
different animal. This is unlikely to be the case for all species shown 
here but is the most comprehensive assessment of the level of impact 
from this activity.
BILLING CODE 3510-22-P

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[[Page 28724]]



Total Proposed Takes Across All Activities

    The amount of Level A harassment and Level B harassment proposed to 
be authorized for all activities considered in this proposed rule (WTG 
and OSS foundation installation, cable landfall construction, and HRG 
surveys) are presented in Table 27. The mitigation and monitoring 
measures provided in the Proposed Mitigation and Proposed Monitoring 
and Reporting sections are activity-specific and are designed to 
minimize acoustic exposures to marine mammal species.
    The take numbers NMFS proposes for authorization (Table 27) are 
considered the maximum number that could occur (i.e., there are 
multiple reasons that there could be fewer) for the following key 
reasons:
     The proposed take accounts for 183 pile driving events 
when only 176 foundations may be installed. It could be that no piles 
will require the need to be re-driven.
     The amount of Level A harassment proposed to be authorized 
considered the maximum of up to two monopiles per day being installed 
and use of acoustic ranges which does not account for animal movement.
     The amount of take, by Level A harassment, proposed to be 
authorized does not account for the likelihood that marine mammals 
would avoid a stimulus when possible before the individual accumulates 
enough acoustic energy to potentially cause auditory injury.
     All take estimates assume all piles are installed in the 
month with the highest average seasonal and/or annual densities for 
each marine mammal species and/or stock based on the construction 
schedule.
     Dominion Energy assumed the maximum number of temporary 
cofferdams (up to nine) and goal posts (up to 108) would be installed 
when, during construction, fewer piles may be installed and, in the 
case of cofferdams, may not be installed at all (Dominion Energy may 
use a gravity-cell structure in lieu of cofferdams which would not 
generate noise levels that would result in marine mammal harassment).
     The amount of take, by Level B harassment, proposed to be 
authorized does not account for the effectiveness of the proposed 
monitoring and mitigation measures, with the exception of use of noise 
attenuation device, for any species.
    The Year 1 take estimates include HRG surveys, vibratory and impact 
installation of WTG and OSS foundations, the impact installation and 
removal of temporary goal posts, and the vibratory installation and 
removal of temporary cofferdams. Year 2 includes HRG surveys and the 
vibratory and impact installation of WTG and OSS foundations. Years 3, 
4, and 5 each include HRG surveys. Dominion Energy has noted that Year 
3 may include some installation of foundation piles for WTGs if they 
fall behind their construction schedule. However, if this occurs, this 
would just reduce the number of WTGs installed in Year 2. Exact 
durations for HRG surveys in each construction are not given although 
estimates are provided above and are repeated here: 65 days in 2024, 
249 days in 2025, 58 days in 2026, and 368 days in each of 2027 and 
2028. These estimates are based on the effort of two concurrently 
operating survey vessels.
    Table 27 shows the estimated take of each species for each year 
based on the planned distribution of activities. Tables 28 and 29 show 
the total take over five years and the maximum take proposed for 
authorization in any one year, respectively.

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[[Page 28730]]


    In making the negligible impact determination and the small numbers 
finding, NMFS assesses the greatest number of proposed take of marine 
mammals that could occur within any one year, which in the case of this 
rule is based on the predicted take in either Year 1 (2024) or Year 2 
(2025), depending on the species and/or stock. In this calculation, the 
maximum estimated number of Level A harassment takes in any one year is 
summed with the maximum estimated number of Level B harassment takes in 
any one year for each species to yield the highest number of estimated 
take that could occur in any year. We recognize that certain activities 
could shift within the 5-year effective period of the rule; however, 
the rule allows for that flexibility and the takes are not expected to 
exceed those shown in Table 29 in any one year.

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BILLING CODE 3510-22-C

[[Page 28734]]

Proposed Mitigation

    In order to promulgate a rulemaking under section 101(a)(5)(A) of 
the MMPA, NMFS must set forth the permissible methods of taking 
pursuant to the activity, and other means of effecting the least 
practicable impact on the species or stock and its habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stock for 
taking for certain subsistence uses (latter not applicable for this 
action). NMFS' regulations require applicants for incidental take 
authorizations to include information about the availability and 
feasibility (economic and technological) of equipment, methods, and 
manner of conducting the activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks and 
their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    The mitigation strategies described below are consistent with those 
required and successfully implemented under previous incidental take 
authorizations issued in association with in-water construction 
activities (e.g., soft-start, establishing shutdown zones). Additional 
measures have also been incorporated to account for the fact that the 
proposed construction activities would occur offshore. Modeling was 
performed to estimate harassment zones, which were used to inform 
mitigation measures for pile driving activities to minimize Level A 
harassment and Level B harassment to the extent practicable while 
providing estimates of the areas within which Level B harassment might 
occur.
    Generally speaking, the measures considered and proposed here fall 
into three categories: temporal (seasonal and daily) work restrictions, 
real-time measures (shutdown, clearance zones, and vessel strike 
avoidance), and noise reduction measures. Seasonal work restrictions 
are designed to avoid or minimize operations when marine mammals are 
concentrated or engaged in behaviors that make them more susceptible or 
make impacts more likely. Temporal restrictions are also designed to 
reduce both the number and severity of potential takes, and are 
effective in reducing both chronic (longer-term) and acute effects. 
Real-time measures, such as clearance and shutdown requirements and 
vessel strike avoidance measures, are intended to reduce the 
probability or scope of near-term acute impacts by taking steps in real 
time once a higher-risk scenario is identified (i.e., once animals are 
detected within an impact zone). Noise reduction measures, such as the 
use of noise abatement devices like bubble curtains, are intended to 
reduce the noise at the source, which reduces both acute impacts as 
well as the contribution to aggregate and cumulative noise that results 
in longer term chronic impacts.
    Below, we describe measures that apply to all activity types, and 
then in the following subsections, we describe the measures that apply 
specifically to WTG and OSS foundation installation, cable landfall 
construction pile driving, HRG surveys, and fishery monitoring surveys.
    Although the language contained in this proposed rule directly 
refers to the applicant, Dominion Energy, all proposed measures 
discussed herein would also apply to any persons Dominion Energy 
authorizes or funds to conduct activities on its behalf specific to the 
CVOW-C project.

Training and Coordination

    All relevant personnel and the marine mammal monitoring team(s) 
would be required to participate in joint, onboard briefings that would 
be led by CVOW-C project personnel and the Lead PSO prior to the 
beginning of project activities. This would serve to ensure that all 
relevant responsibilities, communication procedures, marine mammal 
monitoring and mitigation protocols, reporting protocols, safety, 
operational procedures, and ITA requirements are clearly understood by 
all involved parties. The briefing would be repeated whenever new 
relevant personnel (e.g., new PSOs, acoustic source operators, relevant 
crew) join the operation before work commences. During this training, 
Dominion Energy would be required to instruct all project personnel 
regarding the authority of the marine mammal monitoring team(s). For 
example, the HRG acoustic equipment operator, pile driving personnel, 
etc., would be required to immediately comply with any call for a delay 
or shutdown by the Lead PSO. Any disagreement between the Lead PSO and 
the project personnel would only be discussed after delay or shutdown 
has occurred. More information on vessel crew training requirements can 
be found in the Vessel Strike Avoidance Measures sections below.

Protected Species Observers and PAM Operator Training

    Dominion Energy would employ NMFS-approved PSOs and PAM operators. 
The PSO field team and PAM team would have a lead member (designated as 
the ``Lead PSO'' or ``PAM Lead'') who would have prior experience 
observing mysticetes, odontocetes, and pinnipeds in the northwestern 
Atlantic Ocean on other offshore projects requiring PSOs. Any remaining 
PSOs and PAM operators must have previous experience observing marine 
mammals during projects and must have the ability to work with all 
required and relevant software and equipment. New and/or inexperienced 
PSOs would be paired with an experienced PSO to ensure that the quality 
of marine mammal observations and data recording is kept consistent. 
Additional information on the roles and requirements of the PAM 
operators (section 4.1.1.2) and PSOs (section 4.1.1.3) can be found in 
Dominion Energy's supplemental Protected Species Mitigation and 
Monitoring Plan (PSMMP) on NMFS' website (https://www.fisheries.noaa.gov/action/incidental-take-authorization-dominion-energy-virginia-construction-coastal-virginia).
    Prior to the start of activities, a briefing would be conducted 
between the supervisors, the crew, the PSO/PAM team, the environmental 
compliance monitors, and Dominion Energy personnel. This briefing would 
be to establish the responsibilities of each participating party, to 
define the chains of command, to discuss communication procedures, to 
provide an overview of the monitoring purposes, and to review

[[Page 28735]]

the operational procedures. The designated PSO (i.e., Lead PSO) would 
oversee the training, the environmental compliance monitors, the PSOs, 
and other tasks specifically related to monitoring. More information on 
the specific roles and requirements of the Lead PSO can be found in 
section 4.1.1.1 of Dominion Energy's PSMMP.

North Atlantic Right Whale Awareness Monitoring

    Dominion Energy must use available sources of information on North 
Atlantic right whale presence, including daily monitoring of the Right 
Whale Sightings Advisory System, monitoring of Coast Guard VHF Channel 
16 throughout each day to receive notifications of any sightings, and 
information associated with any regulatory management actions (e.g., 
establishment of a zone identifying the need to reduce vessel speeds). 
Maintaining daily awareness and coordination affords increased 
protection of North Atlantic right whales by understanding North 
Atlantic right whale presence in the area through ongoing visual and 
passive acoustic monitoring efforts and opportunities (outside of 
Dominion Energy's efforts) and allows for planning of construction 
activities, when practicable, to minimize potential impacts on North 
Atlantic right whales.
    Given the CVOW-C project is occurring within the general vicinity 
of the North Atlantic right whale SMA located outside of the mouth of 
the Chesapeake Bay, all vessels would be required to comply with the 
Mid-Atlantic Seasonal Management Area (SMA) mandatory speed restriction 
period (November 1st through April 30th) for all activities. Dominion 
Energy would also be required to monitor the NOAA Fisheries North 
Atlantic Right Whale reporting system for the establishment of a 
Dynamic Management Area (DMA).

Vessel Strike Avoidance Measures

    This proposed rule contains numerous vessel strike avoidance 
measures. Dominion Energy will be required to comply with these 
measures except under circumstances when doing so would create an 
imminent and serious threat to a person or vessel or to the extent that 
a vessel is unable to maneuver and because of the inability to 
maneuver, the vessel cannot comply (e.g., due to towing, etc.). Vessel 
operators and crews will receive protected species identification 
training prior to the start of in-water construction activities. This 
training will cover information about marine mammals and other 
protected species known to occur or which have the potential to occur 
in the project area. It will include training on making observations in 
both good weather conditions (i.e., clear visibility, low wind, and low 
sea state) and bad weather conditions (i.e., fog, high winds and high 
sea states, in glare). Training will not only include identification 
skills but will also include information and resources available 
regarding applicable Federal laws and regulations for protected 
species. In addition, all vessels must be equipped with an Automatic 
Identification System (AIS) and Dominion Energy must report all 
Maritime Mobile Service Identify (MMSI) numbers to NMFS Office of 
Protected Resources prior to initiating in-water activities.
    Dominion Energy will abide by the following vessel strike avoidance 
measures:
     All vessel operators and crews must maintain a vigilant 
watch for all marine mammals and slow down, stop their vessel, or alter 
course (as appropriate) to avoid striking any marine mammal.
     During any vessel transits within or to/from the CVOW-C 
project area, such as for crew transfers, an observer would be 
stationed at the best vantage point of the vessel(s) to ensure that the 
vessel(s) are maintaining the appropriate separation distance from 
marine mammals.
     Year-round and when a vessel is in transit, all vessel 
operators will continuously monitor U.S. Coast Guard VHF Channel 16 
over which North Atlantic right whale sightings are broadcasted.
     At the onset of transiting and at least once every four 
hours, vessel operators and/or trained crew members will monitor the 
project's Situational Awareness System, WhaleAlert, and the Right Whale 
Sighting Advisory System (RWSAS) for the presence of North Atlantic 
right whales.
     Any observations of any large whale by any Dominion Energy 
staff or contractors, including vessel crew, must be communicated 
immediately to PSOs, PAM operator, and all vessel captains to increase 
situational awareness. Conversely, any large whale observation or 
detection via a sighting network (e.g., Mysticetus) by PSOs or PAM 
operators will be conveyed to vessel operators and crew.
     All vessels would comply with existing NMFS regulations 
and speed restrictions and state regulations, as applicable, for North 
Atlantic right whales.
     In the event that any Slow Zone (DMA or acoustically 
triggered slow zone) is established that overlaps with an area where a 
project-associated vessel would operate, that vessel, regardless of 
size, will transit that area at 10 kts or less.
     Between November 1st and April 30th, all vessels, 
regardless of size, would operate at 10 kts or less.
     All vessels, regardless of size, would immediately reduce 
speed to 10 kts or less when any large whale, whale mother/calf pairs, 
or large assemblages of non-delphinid cetaceans are observed near 
(within 100 m) an underway vessel.
     All vessels, regardless of size, would immediately reduce 
speed to 10 kts or less when a North Atlantic right whale is sighted, 
at any distance, by an observer or anyone else on the vessel.
     All transiting vessels (e.g., transiting, surveying) must 
have a dedicated visual observer on duty at all times to monitor for 
marine mammals within a 180[deg] direction of the forward path of the 
vessel (90[deg] port to 90[deg] starboard). Visual observers must be 
equipped with alternative monitoring technology for periods of low 
visibility (e.g., darkness, rain, fog, etc.). The dedicated visual 
observer must receive prior training on protected species detection and 
identification, vessel strike minimization procedures, how and when to 
communicate with the vessel captain, and reporting requirements in this 
proposed action. Visual observers may be third-party observers (i.e., 
NMFS-approved PSOs) or crew members and must not have any other duties 
other than observing for marine mammals. Observer training related to 
these vessel strike avoidance measures must be conducted for all vessel 
operators and crew prior to the start of in-water construction 
activities to distinguish marine mammals from other phenomena and 
broadly to identify a marine mammal as a North Atlantic right whale, 
other whale (defined in this context as sperm whales or baleen whales 
other than North Atlantic right whales), or other marine mammal. 
Confirmation of the observers' training and understanding of the ITA 
requirements must be documented on a training course log sheet and 
reported to NMFS.
     All vessels must maintain a minimum separation distance of 
500 m from North Atlantic right whales. If a whale is observed but 
cannot be confirmed as a species other than a North Atlantic right 
whale, the vessel operator must assume that it is a North Atlantic 
right whale and take appropriate action.
     All transiting vessels must steer a course away from any 
sighted North

[[Page 28736]]

Atlantic right whale at 10 kts or less such that the 500-m minimum 
separation distance requirement is not violated. If a North Atlantic 
right whale or a large whale that cannot be confirmed as a species 
other than a North Atlantic right whale is sighted within 500 m of an 
underway vessel, that vessel must shift the engine to neutral. Engines 
will not be engaged until the whale has moved outside of the vessel's 
path and beyond 500 m. If a whale is observed but cannot be confirmed 
as a species other than a North Atlantic right whale, the vessel 
operator must assume that it is a North Atlantic right whale and take 
appropriate action.
     All vessels must maintain a minimum separation distance of 
100 m from sperm whales and non-North Atlantic right whale baleen 
whales. If one of these species is sighted within 100 m of a transiting 
vessel, that vessel must shift the engine to neutral. Engines will not 
be engaged until the whale has moved outside of the vessel's path and 
beyond 100 m.
     All vessels must, to the maximum extent practicable, 
attempt to maintain a minimum separation distance of 50 m from all 
delphinid cetaceans and pinnipeds with an exception made for those that 
approach the vessel (e.g., bow-riding dolphins). If a delphinid 
cetacean or pinniped is sighted within 50 m of an underway vessel, that 
vessel must shift the engine to neutral (again, with an exception made 
for those that approach the vessel). Engines will not be engaged until 
the animal(s) has moved outside of the vessel's path and beyond 50 m.
     When a marine mammal(s) is sighted while a vessel is 
transiting, the vessel must take action as necessary to maintain the 
relevant separation distances (e.g., attempt to remain parallel to the 
animal's course, avoid excessive speed or abrupt changes in direction 
until the animal has left the area). If a marine mammal(s) is sighted 
within the relevant separation distance, the vessel must reduce speed 
and shift the engine to neutral, not engaging the engine(s) until the 
animal(s) is clear of the area. This does not apply to any vessel 
towing gear or any situation where respecting the relevant separation 
distance would be unsafe (i.e., any situation where the vessel is 
navigationally constrained).
     All transiting vessels must not divert or alter course in 
order to approach any marine mammal.
     For in-water construction heavy machinery activities, 
other than impact or vibratory pile driving, if a marine mammal is on a 
path towards or comes within 10 m of equipment, Dominion Energy must 
cease operations until the marine mammal has moved more than 10 m on a 
path away from the activity to avoid direct interaction with equipment.
     Dominion Energy must submit a North Atlantic right whale 
vessel strike avoidance plan 180 days prior to commencement of vessel 
use. The plan would, at minimum, describe how PAM, in combination with 
visual observations, would be conducted to ensure the transit corridor 
is clear of right whales. The plan would also provide details on the 
vessel-based observer protocols on transiting vessels.

WTG and OSS Foundation Installation

    For WTG and OSS foundation installation, NMFS is proposing to 
include the following mitigation requirements, which are described in 
detail below: seasonal and daily restrictions; the use of noise 
abatement systems; the use of PSOs and PAM operators; the 
implementation of clearance and shutdown zones, and the use of soft-
start.

Seasonal and Daily Restrictions

    No foundation pile driving activities (inclusive of both vibratory 
and impact pile driving) would occur between November 1st through April 
30th of any year. Based on the best scientific information available 
(i.e., Roberts and Halpin, 2022), the highest densities of North 
Atlantic right whales in the project area are expected during the 
months of November through April. NMFS is proposing to require this 
seasonal work restriction to minimize the exposure of North Atlantic 
right whales to noise incidental to both vibratory and impact pile 
driving of monopiles (for the WTGs) and jacket pin piles (for the 
OSSs), which is expected to greatly reduce the number of takes of North 
Atlantic right whales.
    No more than two foundation monopiles would be installed per day. 
Monopiles would be no larger than 9.5-m in diameter, representing the 
larger end of the tapered 9.5/7.5-m monopile design. For all monopiles, 
the minimum amount of hammer energy necessary to effectively and safely 
install and maintain the integrity of the piles must be used. These 
hammer energies must not exceed 4,000 kJ. Similarly, no more than two 
foundation pin piles would be installed per day. Pin piles for jacket 
foundations would be no larger than 2.8-m in diameter. A jacket 
foundation design no larger than a four-legged design must be used 
(four pin piles per jacket foundation). For all pin piles, the minimum 
amount of hammer energy necessary to effectively and safely install and 
maintain the integrity of the piles must be used. These hammer energies 
must not exceed 3,000 kJ.
    Dominion Energy would initiate pile driving (inclusive of both 
vibratory and impact) no earlier than one hour after civil sunrise or 
no later than 1.5 hours before civil sunset. Dominion Energy has not 
proposed nighttime pile driving other than if pile driving continues 
after dark. This would only occur when installation of the same pile 
begins during daylight (i.e., 1.5 hours before civil sunset). Dominion 
Energy would need to adequately monitor all relevant zones to ensure 
the most effective mitigative actions are being undertaken. Additional 
restrictions are discussed in the following Clearance and Shutdown 
Zones section.

Noise Abatement Systems

    Dominion Energy would employ noise abatement systems (NAS), also 
known as noise attenuation systems, during all vibratory and impact 
pile driving of monopiles and pin piles to reduce the sound pressure 
levels that are transmitted through the water in an effort to reduce 
ranges to acoustic thresholds and minimize any acoustic impacts 
resulting from pile driving. Dominion Energy would be required to 
employ a big double bubble curtain (as was used during the CVOW Pilot 
Project), other technology capable of achieving a 10-dB sound level 
reduction, or a combination of two or more NAS capable of achieving a 
10-dB sound level reduction during these activities as well as the 
adjustment of operational protocols to minimize noise levels.
    Two categories of NAS exist: primary and secondary. A primary NAS 
would be used to reduce the level of noise produced by the pile driving 
activities at the source, typically through adjustments on to the 
equipment (e.g., hammer strike parameters). Primary NAS are still 
evolving and will be considered for use during mitigation efforts when 
the NAS has been demonstrated as effective in commercial projects. 
However, as primary NAS are not fully effective at eliminating noise, a 
secondary NAS would be employed. The secondary NAS is a device or group 
of devices that would reduce noise as it was transmitted through the 
water away from the pile, typically through a physical barrier that 
would reflect or absorb sound waves and therefore, reduce the distance 
the higher energy sound propagates through the water column. Together, 
these systems must reduce noise levels to the lowest level practicable 
with the goal of not

[[Page 28737]]

exceeding measured ranges to Level A harassment and Level B harassment 
isopleths corresponding to those modeled assuming 10-dB sound 
attenuation, pending results of Sound Field Verification (SFV; see the 
Acoustic Monitoring for Sound Field and Harassment Isopleth 
Verification section).
    Noise abatement systems, such as bubble curtains, are used to 
decrease the sound levels radiated from a source. Bubbles create a 
local impedance change that acts as a barrier to sound transmission. 
The size of the bubbles determines their effective frequency band, with 
larger bubbles needed for lower frequencies. There are a variety of 
bubble curtain systems, confined or unconfined bubbles, and some with 
encapsulated bubbles or panels. Attenuation levels also vary by type of 
system, frequency band, and location. Small bubble curtains have been 
measured to reduce sound levels but effective attenuation is highly 
dependent on depth of water, current, and configuration and operation 
of the curtain (Austin et al., 2016; Koschinski and L[uuml]demann, 
2013). Bubble curtains vary in terms of the sizes of the bubbles and 
those with larger bubbles tend to perform a bit better and more 
reliably, particularly when deployed with two separate rings (Bellmann, 
2014; Koschinski and L[uuml]demann, 2013; Nehls et al., 2016). 
Encapsulated bubble systems (e.g., Hydro Sound Dampers (HSDs)), can be 
effective within their targeted frequency ranges (e.g., 100-800 Hz), 
and when used in conjunction with a bubble curtain appear to create the 
greatest attenuation. The literature presents a wide array of observed 
attenuation results for bubble curtains. The variability in attenuation 
levels is the result of variation in design as well as differences in 
site conditions and difficulty in properly installing and operating in-
water attenuation devices. Secondary NAS that may be used by Dominion 
Energy include a big bubble curtain (BBC), a hydro-sound damper, or an 
AdBm Helmholz resonator (Elzinga et al., 2019). If a single system is 
used, it must be a double big bubble curtain (dBBC). Other dual systems 
(e.g., noise mitigation screens, hydro-sound damper, AdBm Helmholz 
resonator) are being considered for the CVOW-C project, although many 
of these are in their early stages of development and field tests to 
evaluate performance and effectiveness have not been completed. Should 
the research and development phase of these newer systems demonstrate 
effectiveness, as part of adaptive management, Dominion Energy may 
submit data on the effectiveness of these systems and request approval 
from NMFS to use them during vibratory and impact pile driving.
    The literature presents a wide array of observed attenuation 
results for bubble curtains. The variability in attenuation levels is 
the result of variation in design as well as differences in site 
conditions and difficulty in properly installing and operating in-water 
attenuation devices. D[auml]hne et al. (2017) found that single bubble 
curtains that reduce sound levels by 7 to 10 dB reduced the overall 
sound level by approximately 12 dB when combined as a double bubble 
curtain for 6-m steel monopiles in the North Sea. During installation 
of monopiles (consisting of approximately 8-m in diameter) for more 
than 150 WTGs in comparable water depths (>25 m) and conditions in 
Europe indicate that attenuation of 10 dB is readily achieved 
(Bellmann, 2019; Bellmann et al., 2020) using single BBCs for noise 
attenuation. Designed to gather additional data regarding the efficacy 
of BBCs, the CVOW Pilot Project systematically measured noise resulting 
from the impact driven installation of two 7.8-m diameter monopiles, 
one installation using a dBBC and the other installation using no noise 
abatement system (CVOW, unpublished data). Although many factors 
contributed to variability in received levels throughout the 
installation of the piles (e.g., hammer energy, technical challenges 
during operation of the dBBC), reduction in broadband SEL using the 
dBBC (comparing measurements derived from the mitigated and the 
unmitigated monopiles) ranged from approximately 9-15 dB.
    If a bubble curtain is used (single or double), Dominion Energy 
would be required to maintain the following operational parameters: the 
bubble curtain(s) must distribute air bubbles using a target air flow 
rate of at least 0.5 m\3\/(min*m) and must distribute bubbles around 
100 percent of the piling perimeter for the full depth of the water 
column. The lowest bubble ring must be in contact with the seafloor for 
the full circumference of the ring, and the weights attached to the 
bottom ring must ensure 100-percent seafloor contact; no parts of the 
ring or other objects should prevent full seafloor contact. Dominion 
Energy must require that construction contractors train personnel in 
the proper balancing of airflow to the bubble ring and must require 
that construction contractors submit an inspection/performance report 
for approval by Dominion Energy within 72 hours following the 
performance test. Corrections to the attenuation device to meet the 
performance standards must occur prior to impact driving of monopiles. 
If Dominion Energy uses a noise mitigation device in addition to a BBC, 
similar quality control measures would be required.
    Again, NMFS would require Dominion Energy to apply a dBBC or a 
single BBC coupled with an additional noise mitigation device to ensure 
sound generated from the project does not exceed that modeled (assuming 
10-dB reduction) at given ranges to harassment isopleths and to 
minimize noise levels to the lowest level practicable. Double BBCs are 
successfully and widely applied across European wind development 
efforts and are known to reduce noise levels more than single BBC alone 
(e.g., Bellman et al., 2020). Dominion Energy anticipates and NMFS 
agrees that the use of a noise abatement system would likely produce 
field measurements of the isopleth distances to the Level A harassment 
and Level B harassment thresholds that accord with those modeled 
assuming 10-dB of attenuation for vibratory and impact pile driving of 
monopiles and pin piles (refer back to the Estimated Take, Proposed 
Mitigation, and Proposed Monitoring and Reporting sections).

Use of PSOs and PAM Operators

    As described above, Dominion Energy would be required to use PSOs 
and acoustic PSOs (i.e., PAM operators) during all WTG and OSS 
foundation installation activities. Dominion Energy would be required 
to utilize a team of sufficient size to allow for appropriate 
implementation of mitigation measures and monitoring. At a minimum, 
four PSOs would be actively observing marine mammals before, during, 
and after pile driving. At least two PSOs would be stationed on the 
primary pile driving installation vessel and at least two PSOs would be 
stationed on a secondary, dedicated PSO vessel. The dedicated PSO 
vessel would be positioned approximately 3 km from the pile being 
driven and circle the pile at a speed of less than 10 kts. 
Concurrently, at least one PAM operator would be actively monitoring 
for marine mammals before, during, and after pile driving. PSOs 
fulfilling the role of both the PAM operator and PSO may be utilized 
interchangeably, if all relevant experience and educational 
requirements are met; however, PAM operators/PSOs must only serve in 
one capacity per watch period. During all monopile installation and in 
the two days prior to and daily throughout the construction, the Lead 
PSO would continue to consult the NOAA Fisheries

[[Page 28738]]

North Atlantic right whale reporting systems for the presence of North 
Atlantic right whales. More details on PSO and PAM operator 
requirements can be found in the Proposed Monitoring and Reporting 
section.
    As a requirement that is not only exclusive to PAM operators and 
PSOs, all crew and personnel working on the CVOW-C project would be 
required to maintain situational awareness of marine mammal presence 
(discussed further above) and would be required to report any sightings 
to the PSOs for implementation of mitigation measures, if necessary.

Clearance and Shutdown Zones

    NMFS is proposing to require the establishment of both clearance 
and shutdown zones during all impact and vibratory pile driving of 
monopiles and pin piles, which would be monitored by visual PSOs and 
PAM operators before, during and after pile driving. PSOs must visually 
monitor clearance zones for marine mammals for a minimum of 60 minutes 
immediately prior to commencing pile driving. At least one PAM operator 
must review data from at least 24 hours prior to pile driving and 
actively monitor hydrophones for 60 minutes immediately prior to pile 
driving. Prior to initiating soft-start procedures, all clearance zones 
must be visually confirmed to be free of marine mammals for 30 minutes 
immediately prior to starting a soft-start of pile driving. If a marine 
mammal is observed entering or within the relevant clearance zone prior 
to the initiation of impact pile driving activities, pile driving must 
be delayed and will not begin until either the marine mammal(s) has 
voluntarily left the specific clearance zones and have been visually or 
acoustically confirmed beyond that clearance zone or when specific time 
periods have elapsed with no further sightings or acoustic detections 
have occurred (i.e., 15 minutes for small odontocetes and 30 minutes 
for all other marine mammal species).
    The purpose of ``clearance'' of a particular zone is to prevent or 
minimize potential instances of auditory injury and more severe 
behavioral disturbances by delaying the commencement of impact pile 
driving if marine mammals are near the activity. Prior to the start of 
impact pile driving activities, Dominion Energy would ensure the area 
is clear of marine mammals, per the clearance zones presented in Tables 
30 and 31, to minimize the potential for and degree of harassment. Once 
pile driving activity begins, any marine mammal entering the shutdown 
zone would trigger pile driving to cease (unless shutdown is not 
practicable due to imminent risk of injury or loss of life to an 
individual or risk of damage to a vessel that creates risk of injury or 
loss of life for individuals). The purpose of a shutdown is to prevent 
a specific acute impact, such as auditory injury or severe behavioral 
disturbance of sensitive species, by halting the activity.
    In addition to the clearance and shutdown zones that would be 
monitored both visually and acoustically, NMFS is proposing to 
establish a minimum visibility zone to ensure both visual and acoustic 
methods are used in tandem to detect marine mammals resulting in 
maximum detection capability. The minimum visibility zone that has been 
proposed by Dominion Energy would extend 1,750 m from the pile being 
driven during all months in which foundation installation is planned to 
occur. This value was proposed by Dominion Energy as it corresponds to 
the Exclusion Zone implemented during the CVOW Pilot Project (see 85 FR 
30930, May 21, 2020). While NMFS acknowledges that this distance was 
adequate and appropriate for the CVOW Pilot Project, the turbine models 
for the proposed CVOW-C project are much larger (7.8-m versus 9.5-m, 
respectively) and would require a much larger maximum hammer energy 
(1,000 kJ maximum versus 4,000 kJ maximum). These factors create a 
larger distance to the Level A harassment threshold than the CVOW Pilot 
Project. Because of these reasons, NMFS has instead proposed a minimum 
visibility distance for WTG monopile and OSS pin pile installation as 
2,000 m.
    During all foundation installation, Dominion Energy must ensure 
that the entire minimum visibility zone (as based on the installation 
activity occurring) is visible (i.e., not obscured by dark, rain, fog, 
etc.) for a full 30 minutes immediately prior to commencing vibratory 
or impact pile driving. In addition, the entire clearance zone must be 
visually clear of marine mammals prior to commencing vibratory or 
impact pile driving. For North Atlantic right whales, there is an 
additional requirement that the clearance zone may only be declared 
clear if no confirmed North Atlantic right whale acoustic detections 
(in addition to visual) have occurred during the 60-minute monitoring 
period. Any large whale sighted by a PSO or acoustically detected by a 
PAM operator that cannot be identified as a non-North Atlantic right 
whale must be treated as if it were a North Atlantic right whale.
    Proposed clearance and shutdown zones have been developed in 
consideration of modeled distances to relevant PTS thresholds with 
respect to minimizing the potential for take by Level A harassment. All 
proposed clearance and shutdown zones for large whales are larger than 
the largest modeled acoustic range (R95) distances 
to thresholds corresponding to Level A harassment (SEL and peak).
    If a marine mammal is observed entering or within the respective 
shutdown zone (Tables 30 and 31) after pile driving has begun, the PSO 
will request a temporary cessation of pile driving. Dominion Energy 
will stop pile driving immediately unless Dominion Energy determines 
shutdown is not practicable due to imminent risk of injury or loss of 
life to an individual or risk of damage to a vessel that creates risk 
of injury or loss of life for individuals or the lead engineer 
determines there is pile refusal or pile instability. Pile refusal 
occurs when the pile driving sensors indicate the pile is approaching 
refusal, and a shut-down would lead to a stuck pile which then poses an 
imminent risk of injury or loss of life. Pile instability occurs when 
the pile is unstable and unable to stay standing if the piling vessel 
were to ``let go.'' During these periods of instability, the lead 
engineer may determine a shutdown is not feasible because the shutdown 
combined with impending weather conditions may require the piling 
vessel to ``let go'', which then poses an imminent risk of injury or 
loss of life, pile refusal, or pile instability. In any of these 
situations, Dominion Energy must reduce hammer energy to the lowest 
level practicable and the reason(s) for not shutting down must be 
documented and reported to NMFS.
    The lead engineer must evaluate the following to determine if a 
shutdown is safe and practicable:
    a. Use of site-specific soil data and real-time hammer log 
information to judge whether a stoppage would risk causing piling 
refusal at re-start of piling;
    b. Confirmation that pile penetration is deep enough to secure pile 
stability in the interim situation, taking into account weather 
statistics for the relevant season and the current weather forecast; 
and
    c. Determination by the lead engineer on duty will be made for each 
pile as the installation progresses and not for the site as a whole.
    If it is determined that shutdown is not feasible, the reason must 
be documented and reported (see Proposed Monitoring and Reporting 
section).

[[Page 28739]]

    Subsequent restart of the equipment can be initiated if the animal 
has been observed exiting its respective shutdown zone within 30 
minutes of the shutdown, or, after an additional time period has 
elapsed with no further sighting (i.e., 15 minutes for small 
odontocetes and pinnipeds and 30 minutes for all other species).
    The clearance and shutdown zone sizes vary by species and are shown 
in Tables 30 and 31. All distances to the perimeter of these mitigation 
zones are the radii from the center of the pile. Pursuant to the 
proposed adaptive management provisions, Dominion Energy may request 
modification to these zone sizes pending results of sound field 
verification (see Proposed Monitoring and Reporting section). Any 
changes to zone size would require NMFS' prior approval.
BILLING CODE 3510-22-P

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[GRAPHIC] [TIFF OMITTED] TP04MY23.101


[[Page 28741]]


[GRAPHIC] [TIFF OMITTED] TP04MY23.102

BILLING CODE 3510-22-C

[[Page 28742]]

Soft-Start

    The use of a soft-start procedure is believed to provide additional 
protection to marine mammals by warning them or providing them with a 
chance to leave the area prior to the hammer operating at full 
capacity. Soft-start typically involves initiating hammer operation at 
a reduced energy level (relative to full operating capacity) followed 
by a waiting period. Dominion Energy must utilize a soft-start protocol 
for impact pile driving of monopiles by performing 4-6 strikes per 
minute at 10 to 20 percent of the maximum hammer energy for a minimum 
of 30 minutes.
    Soft-start will be required at the beginning of each day's monopile 
and pin pile installation and at any time following a cessation of 
vibratory or impact pile driving of 30 minutes or longer. If a marine 
mammal is detected within or about to enter the applicable clearance 
zones prior to the beginning of soft-start procedures, impact pile 
driving would be delayed until the animal has been visually observed 
exiting the clearance zone or until a specific time period has elapsed 
with no further sightings (i.e., 15 minutes for small odontocetes and 
30 minutes for all other species).

Cable Landfall Activities--Temporary Cofferdams

    For the installation and removal of temporary cofferdams, NMFS is 
proposing to include the following mitigation requirements, which are 
described in detail below: daily restrictions; the use of PSOs; and the 
implementation of clearance and shutdown zones. Given the short 
duration of work and lower noise levels during vibratory driving, NMFS 
is not proposing to require PAM or noise abatement system use during 
these activities.

Seasonal and Daily Restrictions

    Dominion Energy has proposed to install and remove all sheet piles 
associated with temporary cofferdams within the first year of the 
effective period of the regulations and LOA and has proposed to only 
perform these activities within the same seasonal work window as 
previously specified for foundation installation (i.e., May 1st through 
October 31st). Dominion Energy also proposes to conduct pile driving 
associated with cable landfall construction during daylight hours. NMFS 
has carried forward these measures in this proposed rule.

Use of PSOs

    Prior to the start of vibratory pile driving activities, at least 
two PSOs located at the best vantage points would monitor the clearance 
zone for 30 minutes, continue monitoring during vibratory pile driving, 
and for 30 minutes following cessation of the activity. The clearance 
zones must be fully visible for at least 30 minutes and all marine 
mammal(s) must be confirmed to be outside of the clearance zone for at 
least 30 minutes immediately prior to initiation of the activity.

Clearance and Shutdown Zones

    Dominion Energy would establish clearance and shutdown zones for 
vibratory pile driving activities associated with sheet pile 
installation (Table 32). If a marine mammal is observed entering or is 
observed within the respective zones, activities will not commence 
until the animal has exited the zone or a specific amount of time has 
elapsed since the last sighting (i.e., 30 minutes for large whales and 
15 minutes for odontocetes and pinnipeds). If a marine mammal is 
observed entering or within the respective shutdown zone after 
vibratory pile driving has begun, the PSO will call for a temporary 
cessation of the activity. Pile driving must not be restarted until 
either the marine mammal(s) has voluntarily left the specific clearance 
zones and has been visually confirmed beyond that clearance zone or 
when specific time periods have elapsed with no further sightings or 
acoustic detections have occurred (i.e., 15 minutes for small 
odontocetes and 30 minutes for all other marine mammal species). 
Because a vibratory hammer can grip a pile without operating, pile 
instability should not be a concern and no caveat for not ceasing pile 
driving due to pile instability would be allowed. However, the lead 
engineer may determine that pile driving cannot cease due to risk to 
human safety or equipment damage.
    The clearance and shutdown zone sizes vary by species and are shown 
in Table 32. All distances to the perimeter of these mitigation zones 
are the radii from the center of the pile. Dominion Energy is not 
proposing, and NMFS is not requiring, sound field verification, hence 
these distances would not change.

 Table 32--Distances to Mitigation Zones During Nearshore Cable Landfall
                               Activities
                         [Temporary Cofferdams]
------------------------------------------------------------------------
                                            Installation and removal of
                                               temporary cofferdams
             Marine mammals              -------------------------------
                                          Clearance zone   Shutdown zone
                                                (m)             (m)
------------------------------------------------------------------------
North Atlantic right whale--visual
 detection..............................           Any distance
                                         -------------------------------
All other Mysticetes and sperm whales...           1,000           1,000
Delphinids..............................             250             100
Pilot whales............................           1,000           1,000
Harbor porpoises........................             250             100
Seals...................................             250             100
------------------------------------------------------------------------

Cable Landfall Activities--Temporary Goal Posts

    For the installation of temporary goal posts, NMFS is proposing to 
include the following mitigation requirements, which are described in 
detail below: daily restrictions; the use of PSOs; the implementation 
of clearance and shutdown zones; and the use of soft-start. Given the 
short duration of work and relatively small harassment zones, NMFS is 
not proposing to require PAM or noise abatement system use during these 
activities.

Seasonal and Daily Restrictions

    Dominion Energy has proposed to install all pile pipes associated 
with temporary goal posts within the first year of the effective period 
of the regulations and LOA and has proposed to only perform these 
activities within the same seasonal work window as

[[Page 28743]]

previously specified for foundation installation (i.e., May 1st through 
October 31st). Similar to cofferdam work, Dominion Energy is not 
proposing to conduct goal post installation during daylight hours. 
Because removal of goal posts would be conducted via means that do not 
produce noise (see the Description of the Specified Activities 
section), removal could occur during darkness.

Use of PSOs

    Prior to the start of impact hammering activities, at least two 
PSOs located at the best vantage points would monitor the clearance 
zone for 30 minutes, continue monitoring during impact pile driving, 
and for 30 minutes following cessation of the activity. The clearance 
zones must be fully visible for at least 30 minutes and all marine 
mammal(s) must be confirmed to be outside of the clearance zone for at 
least 30 minutes immediately prior to initiation of the activity.

Clearance and Shutdown Zones

    Dominion Energy would establish clearance and shutdown zones for 
impact pile driving for casing pipe installation (Table 33). If a 
marine mammal is observed entering or is observed within the respective 
zones, activities will not commence until the animal has exited the 
zone or a specific amount of time has elapsed since the last sighting 
(i.e., 30 minutes for large whales and 15 minutes for dolphins, 
porpoises, and pinnipeds). If a marine mammal is observed entering or 
within the respective shutdown zone after impact pile driving has 
begun, the PSO will call for a temporary cessation of the activity. 
Pile driving must not be restarted until either the marine mammal(s) 
has voluntarily left the specific clearance zones and has been visually 
confirmed beyond that clearance zone or when specific time periods have 
elapsed with no further sightings or acoustic detections have occurred 
(i.e., 15 minutes for small odontocetes and 30 minutes for all other 
marine mammal species).
    The clearance and shutdown zone sizes vary by species and are shown 
in Table 33. All distances to the perimeter of these mitigation zones 
are the radii from the center of the pile. Dominion Energy is not 
proposing, and NMFS is not requiring, sound field verification, hence 
these distances would not change.

 Table 33--Distances to Mitigation Zones During Nearshore Cable Landfall
                               Activities
                         [Temporary Goal Posts]
------------------------------------------------------------------------
                                          Installation of temporary goal
                                                       posts
             Marine mammals              -------------------------------
                                          Clearance zone   Shutdown zone
                                                (m)             (m)
------------------------------------------------------------------------
North Atlantic right whale--visual
 detection..............................           Any distance
                                         -------------------------------
All other Mysticetes and sperm whales...           1,000           1,000
Delphinids..............................             250             100
Pilot whales............................           1,000           1,000
Harbor porpoises........................             750             100
Seals...................................             500             100
------------------------------------------------------------------------

Soft-Start

    Dominion Energy did not provide specific details in either their 
ITA application or their PSMMP as to the soft-start plan that would be 
implemented for piles associated with temporary goal posts, however, 
NMFS proposes the following approach below, which is similar to the 
soft-start requirements proposed for WTG and OSS foundation 
installation via impact pile driving.
    Dominion Energy must utilize a soft-start protocol for impact pile 
driving of goal post pipe piles. Soft start requires contractors to 
provide an initial set of three strikes at reduced energy, followed by 
a 30-second waiting period, then two subsequent reduced-energy strike 
sets. Soft-start will be required at the beginning of the installation 
procedure for each goal post pipe pile and at any time following a 
cessation of impact pile driving of 30 minutes or longer. If a marine 
mammal is detected within or about to enter the applicable clearance 
zones prior to the beginning of soft-start procedures, impact pile 
driving would be delayed until the animal has been visually observed 
exiting the clearance zone or until a specific time period has elapsed 
with no further sightings (i.e., 15 minutes for small odontocetes and 
30 minutes for all other species).

HRG Surveys

    For HRG surveys, NMFS is proposing to include the following 
mitigation requirements, which are described in detail below, for all 
HRG survey activities using boomers, sparkers, and CHIRPs: the use of 
PSOs; the implementation of clearance, shutdown, and vessel separation 
zones; and ramp-up of survey equipment.
    There are no mitigation measures prescribed for sound sources 
operating at frequencies greater than 180 kHz as these would be 
expected to fall outside of marine mammal hearing ranges and not result 
in harassment; however, all HRG survey vessels would be subject to the 
aforementioned vessel strike avoidance measures described earlier in 
this section. Furthermore, due to the frequency range and 
characteristics of some of the sound sources, take is not anticipated 
for non-impulsive sources (e.g., Ultra-Short BaseLine (USBL) and other 
parametric sub-bottom profilers) with exception to usage of CHIRPS and 
other non-parametric sub-bottom profilers. Hence, mitigation measures 
are only prescribed for CHIRPS, boomers and sparkers.
    PAM would not be required during HRG surveys. While NMFS agrees 
that PAM can be an important tool for augmenting detection capabilities 
in certain circumstances, its utility in further reducing impacts 
during HRG survey activities is limited. We have provided a thorough 
description of our reasoning for not requiring PAM during previous HRG 
surveys in several Federal Register notices (e.g., 87 FR 40796, July 8, 
2022; 87 FR 52913, August 3, 2022; 87 FR 51356, August 22, 2022).

Seasonal and Daily Restrictions

    Given the potential impacts to marine mammals from exposure to HRG 
survey noise sources are relatively minor (e.g., limited to Level B 
harassment) and that the distances to the Level B harassment isopleth 
are very small (maximum

[[Page 28744]]

distance is 100 m via the GeoMarine Dual 400 Sparker at 800 J), NMFS is 
not proposing to implement any seasonal or time-of-day restrictions for 
HRG surveys.
    Although no temporal restrictions are proposed, NMFS would require 
Dominion Energy to deactivate acoustic sources during periods where no 
data is being collected except as determined necessary for testing. Any 
unnecessary use of the acoustic source would be avoided.

Use of PSOs

    During all HRG survey activities using boomers, sparkers, and 
CHIRPS, one PSO would be required to monitor during daylight hours and 
two would be required to monitor during nighttime hours per vessel. 
PSOs would begin visually monitoring 30 minutes prior to the initiation 
of the specified acoustic source (i.e., ramp-up, if applicable) through 
30 minutes after the use of the specified acoustic source has ceased. 
PSOs would be required to monitor the appropriate clearance and 
shutdown zones. These zones would be based around the radial distance 
from the acoustic source and not from the vessel.

Clearance, Shutdown, and Vessel Separation Zones

    Dominion Energy would be required to implement a 30-minute 
clearance period of the clearance zones (Table 34) immediately prior to 
the commencing of the survey or when there is more than a 30-minute 
break in survey activities and PSOs have not been actively monitoring. 
The clearance zones would be monitored by PSOs using the appropriate 
visual technology. If a marine mammal is observed within a clearance 
zone during the clearance period, ramp-up (described below) may not 
begin until the animal(s) has been observed voluntarily exiting its 
respective clearance zone or until an additional time period has 
elapsed with no further sighting (i.e., 15 minutes for small 
odontocetes and seals, and 30 minutes for all other species). In any 
case when the clearance process has begun in conditions with good 
visibility, including via the use of night vision equipment (IR/thermal 
camera), and the Lead PSO has determined that the clearance zones are 
clear of marine mammals, survey operations would be allowed to commence 
(i.e., no delay is required) despite periods of inclement weather and/
or loss of daylight.
    Once the survey has commenced, Dominion Energy would be required to 
shut down boomers, sparkers, and CHIRPs if a marine mammal enters a 
respective shutdown zone (Table 34). In cases when the shutdown zones 
become obscured for brief periods due to inclement weather, survey 
operations would be allowed to continue (i.e., no shutdown is required) 
so long as no marine mammals have been detected. The use of boomers, 
sparkers, and CHIRPs would not be allowed to commence or resume until 
the animal(s) has been confirmed to have left the shutdown zone or 
until a full 15 minutes (for small odontocetes and seals) or 30 minutes 
(for all other marine mammals) have elapsed with no further sighting. 
Any large whale sighted by a PSO within 1,000 m of the boomers, 
sparkers, and CHIRPs that cannot be identified as a non-North Atlantic 
right whale must be treated as if it were a North Atlantic right whale.
    The shutdown requirement would be waived for small delphinids of 
the following genera: Delphinus, Stenella, Lagenorhynchus, and 
Tursiops. Specifically, if a delphinid from the specified genera is 
visually detected approaching the vessel (i.e., to bow-ride) or towed 
equipment, shutdown would not be required. Furthermore, if there is 
uncertainty regarding identification of a marine mammal species (i.e., 
whether the observed marine mammal(s) belongs to one of the delphinid 
genera for which shutdown is waived), the PSOs would use their best 
professional judgment in making the decision to call for a shutdown. 
Shutdown would be required if a delphinid that belongs to a genus other 
than those specified is detected in the shutdown zone.
    If a boomer, sparker, or CHIRP is shut down for reasons other than 
mitigation (e.g., mechanical difficulty) for less than 30 minutes, it 
would be allowed to be activated again without ramp-up only if (1) PSOs 
have maintained constant observation, and (2) no additional detections 
of any marine mammal occurred within the respective shutdown zones. If 
a boomer, sparker, or CHIRP was shut down for a period longer than 30 
minutes, then all clearance and ramp-up procedures would be required, 
as previously described.

     Table 34--Distances to the Mitigation Zones During HRG Surveys
------------------------------------------------------------------------
                                                    HRG surveys
                                         -------------------------------
             Marine mammals               Clearance zone   Shutdown zone
                                                (m)             (m)
------------------------------------------------------------------------
North Atlantic right whale--visual                   500             500
 detection..............................
Endangered species (excluding North                  500             500
 Atlantic right whales).................
All other marine mammals \a\............             100             100
------------------------------------------------------------------------
\a\ Exceptions are noted for delphinids from genera Delphinus,
  Lagenorhynchus, Stenella, or Tursiops and seals.

Ramp-Up

    At the start or restart of the use of boomers, sparkers, and/or 
CHIRPs, a ramp-up procedure would be required unless the equipment 
operates on a binary on/off switch. A ramp-up procedure, involving a 
gradual increase in source level output, is required at all times as 
part of the activation of the acoustic source when technically 
feasible. Operators would ramp up sources to half power for 5 minutes 
and then proceed to full power. Prior to a ramp-up procedure starting, 
the operator would have to notify the Lead PSO of the planned start of 
the ramp-up. This notification time would not be less than 60 minutes 
prior to the planned ramp-up activities as all relevant PSOs would need 
the appropriate 30 minute period to monitor prior to the initiation of 
ramp-up. Prior to ramp-up beginning, the operator must receive 
confirmation from the PSO that the clearance zone is clear of any 
marine mammals. All ramp-ups would be scheduled to minimize the overall 
time spent with the source being activated. The ramp-up procedure must 
be used at the beginning of HRG survey activities or after more than a 
30-minute break in survey activities using the specified HRG equipment 
to provide additional protection to marine mammals in or near the 
survey area by allowing them to vacate the area prior to operation of 
survey equipment at full power.
    Dominion Energy would not initiate ramp-up until the clearance 
process has been completed (see Clearance and Shutdown Zones section 
above). Ramp-

[[Page 28745]]

up activities would be delayed if a marine mammal(s) enters its 
respective clearance zone. Ramp-up would only be reinitiated if the 
animal(s) has been observed exiting its respective shutdown zone or 
until additional time has elapsed with no further sighting (i.e., 15 
minutes for small odontocetes and seals, and 30 minutes for all other 
species).

Fishery Monitoring Surveys

    For all pot/trap surveys, Dominion Energy would implement marine 
mammal monitoring and gear interaction avoidance measures to ensure no 
marine mammals are taken (e.g., entangled) during the surveys. 
Monitoring measures would be implemented based on the Atlantic Large 
Whale Take Reduction Plan (50 CFR 229.32).
    All captains and crew conducting the surveys will be trained in 
marine mammal detection and identification. Dominion Energy and/or its 
cooperating institutions, contracted vessels, or commercially-hired 
captains must implement the following ``move-on'' rule. If marine 
mammals are sighted within 1 nm of the planned location in the 15 
minutes before gear deployment, Dominion Energy and/or its cooperating 
institutions, contracted vessels, or commercially-hired captains, as 
appropriate, may decide to move the vessel away from the marine mammal 
to a different section of the sampling area if the animal appears to be 
at risk of interaction with the gear, based on best professional 
judgment. If, after moving on, marine mammals are still visible from 
the vessel, Dominion Energy and/or its cooperating institutions, 
contracted vessels, or commercially-hired captains may decide to move 
again or to skip the station. Gear would not be deployed if marine 
mammals are observed within the area and if a marine mammal is deemed 
to be at risk of interaction, all gear will be immediately removed. 
Dominion Energy and/or its cooperating institutions must deploy pot 
gear as soon as is practicable upon arrival at the sampling station. 
Dominion Energy and/or its cooperating institutions must initiate 
marine mammal watches (visual observation) no less than 15 minutes 
prior to both deployment and retrieval of the pot gear. Marine mammal 
watches must be conducted by scanning these surrounding waters with the 
naked eye and binoculars and monitoring effort must be maintained 
during the entire period of the time that gear is in the water (i.e., 
throughout gear deployment, fishing, and retrieval).
    If marine mammals are sighted near the vessel during the soak and 
are determined to be at risk of interacting with the gear, then 
Dominion Energy and/or its cooperating institutions, contracted 
vessels, or commercially-hired captains must immediately and carefully 
retrieve the gear as quickly as possible. Dominion Energy and/or its 
cooperating institutions, contracted vessels, or commercially-hired 
captains may use best professional judgment in making this decision. 
Dominion Energy and/or its cooperating institutions, contracted 
vessels, or commercially-hired captains must ensure that surveys deploy 
gear fulfilling all pot universal commercial gear configurations such 
as weak link requirements and marking requirements as specified by 
applicable take reduction plans as required for commercial pot 
fisheries. Dominion Energy will be using on-demand fishing systems 
aimed at reducing the entanglement risk to protected species. These 
systems include, but are not limited to, spooled systems, buoy and 
stowed systems, lift bag systems, and grappling. All gear must be 
clearly labeled as attributed to Dominion Energy's fishery surveys. All 
fisheries monitoring gear must be fully cleaned and repaired (if 
damaged) before each use. Any lost gear associated with the fishery 
surveys will be reported to the NOAA Greater Atlantic Regional 
Fisheries Office Protected Resources Division ([email protected]) as soon as possible or within 24 hours of the documented 
time of missing or lost gear. This report must include information on 
any markings on the gear and any efforts undertaken or planned to 
recover the gear. Finally, all survey vessels will adhere to all vessel 
mitigation measures (see the Proposed Mitigation section).
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures would provide the 
means of affecting the least practicable impact on the affected species 
or stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to promulgate a rulemaking for an activity, section 
101(a)(5)(A) of the MMPA states that NMFS must set forth requirements 
pertaining to the monitoring and reporting of such taking. The MMPA 
implementing regulations at 50 CFR 216.104(a)(13) indicate that 
requests for authorizations must include the suggested means of 
accomplishing the necessary monitoring and reporting that will result 
in increased knowledge of the species and of the level of taking or 
impacts on populations of marine mammals that are expected to be 
present in the proposed action area. Effective reporting is critical 
both to compliance as well as ensuring that the most value is obtained 
from the required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and/or
     Mitigation and monitoring effectiveness.
    Separately, monitoring is also regularly used to support mitigation 
implementation, which is referred to as mitigation monitoring, and 
monitoring plans typically include measures that both support 
mitigation implementation and increase our understanding of the impacts 
of the activity on marine mammals.
    During Dominion Energy's construction activities, visual monitoring 
by NMFS-approved PSOs would be conducted before, during, and after 
impact pile driving, vibratory pile driving, and HRG surveys. PAM would 
also be conducted during all impact pile driving. Observations and 
acoustic detections by PSOs would be used to support the activity-
specific mitigation

[[Page 28746]]

measures described above. Also, to increase understanding of the 
impacts of the activity on marine mammals, observers would record all 
incidents of marine mammal occurrence at any distance from the 
vibratory/impact piling and during active HRG acoustic sources, and 
monitors would document all behaviors and behavioral changes, in 
concert with distance from an acoustic source. The required monitoring 
is described below, beginning with PSO measures that are applicable to 
all activities or monitoring and followed by activity-specific 
monitoring requirements.
    Again, we specify here that although the language contained in this 
proposed rule directly refers to the applicant, Dominion Energy, all 
proposed measures discussed herein would also apply to any contractors 
or other agents working for Dominion Energy specific to the CVOW-C 
project.

PSO and PAM Operator Requirements

    Dominion Energy would be required to collect sighting, behavioral 
response, and acoustic data related to construction activities for 
marine mammal species observed in the region of the activity during the 
period in which the activities occur using NMFS-approved visual PSOs 
and acoustic PAM operators (see Proposed Mitigation section). All 
observers must be trained in marine mammal identification and behaviors 
and are required to have no other construction-related tasks while 
conducting monitoring. PSOs would monitor all clearance and shutdown 
zones prior to, during, and following impact pile driving, vibratory 
pile driving, and during HRG surveys using boomers, sparkers, and 
CHIRPs (with monitoring durations specified further below). PSOs will 
also monitor the Level B harassment zones to the extent practicable 
(noting that some zones are too large to fully observe) and beyond and 
will document any marine mammals observed. Observers would be located 
at the best practicable vantage points on the pile driving vessel and, 
where required, on an aerial platform. Full details regarding all 
marine mammal monitoring must be included in relevant Plans (e.g., Pile 
Driving and Marine Mammal Monitoring Plan) that, under this proposed 
action, Dominion Energy would be required to submit to NMFS for 
approval at least 180 days in advance of the commencement of any 
construction activities.
    The following measures apply to all visual monitoring efforts:
    1. Monitoring must be conducted by NMFS-approved, trained PSOs and 
PAM operators. PSOs must be placed at the primary location relevant to 
the activity (i.e., pile driving vessel, HRG survey vessel) and on any 
necessary dedicated PSO vessels (e.g., additional pile driving 
vessel(s), if required). PSOs must be in the best vantage point(s) 
position in order to ensure 360[deg] visual coverage of the entire 
clearance and shutdown zones, around the observing platform and as much 
of the Level B harassment zone as possible while still maintaining a 
safe work environment;
    2. PSO and PAM operators must be independent third-party observers 
and must have no tasks other than to conduct observational effort, 
collect data, and communicate with and instruct the relevant vessel 
crew with regard to the presence of protected species and mitigation 
requirements;
    3. PSOs may not exceed 4 consecutive watch hours, must have a 
minimum 2-hour break between watches, and may not exceed a combined 
watch schedule of more than 12 hours in a single 24-hour period;
    4. PSOs would be required to use appropriate equipment (specified 
below) to monitor for marine mammals. During periods of low visibility 
(e.g., darkness, rain, fog, poor weather conditions, etc.), PSOs would 
be required to use alternative technologies (i.e., infrared or thermal 
cameras) to monitor the shutdown and clearance zones; and
    5. PSOs must be in the best vantage point to monitor for marine 
mammals and implement the relevant clearance and shutdown procedures, 
when determined to be applicable.
    6. PSOs should have the following minimum qualifications:
    a. Visual acuity in both eyes (corrected is permissible) sufficient 
for discernment of moving targets at the water's surface with the 
ability to estimate the target size and distance. The use of binoculars 
is permitted and may be necessary to correctly identify the target(s);
    b. Ability to conduct field observations and collect data according 
to the assigned protocols;
    c. Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    d. Writing skills sufficient to document observations, including 
but not limited to: the number and species of marine mammals observed, 
the dates and times of when in-water construction activities were 
conducted, the dates and time when in-water construction activities 
were suspended to avoid potential incidental injury of marine mammals 
from construction noise within a defined shutdown zone, and marine 
mammal behavior; and
    e. Ability to communicate orally, by radio, or in-person, with 
project personnel to provide real-time information on marine mammals 
observed in the area, as necessary.
    Observer teams employed by Dominion Energy, in satisfaction of the 
mitigation and monitoring requirements described herein, must meet the 
following additional requirements:
    7. PSOs must successfully complete relevant training, including 
completion of all required coursework and a written and/or oral 
examination developed for the training;
    8. PSOs must have successfully attained a bachelor's degree from an 
accredited college or university with a major in one of the natural 
sciences, a minimum of 30 semester hours or equivalent in the 
biological sciences, and at least one undergraduate course in math or 
statistics. The educational requirements may be waived if the PSO has 
acquired the relevant skills through alternate experience. Requests for 
such a waiver shall be submitted to NMFS and must include written 
justification. Alternate experience that may be considered includes, 
but is not limited to: Secondary education and/or experience comparable 
to PSO duties; previous work experience conducting academic, 
commercial, or government sponsored marine mammal surveys; or previous 
work experience as a PSO; the PSO should demonstrate good standing and 
consistently good performance of PSO duties;
    9. One observer will be designated as lead observer or monitoring 
coordinator (``Lead PSO''). This Lead PSO would be required to have a 
minimum of 90 days of at-sea experience working in this role in an 
offshore environment and would be required to have no more than 
eighteen months elapsed since the conclusion of their last at-sea 
experience;
    10. At least one PSO located on platforms (either vessel-based or 
aerial) would be required to have a minimum of 90 days of at-sea 
experience working in this role in an offshore environment and would be 
required to have no more than eighteen months elapsed since the 
conclusion of their last at-sea experience; and
    11. All PSOs and PAM operators must be approved by NMFS. Dominion 
Energy would be required to submit resumes of the initial set of PSOs 
necessary to commence the project to NMFS Office of Protected Resources 
(OPR) for approval at least 60 days prior to the first day of in-water 
construction activities requiring PSOs. Resumes

[[Page 28747]]

would need to include the dates of training and any prior NMFS approval 
as well as the dates and description of their last PSO experience and 
must be accompanied by information documenting their successful 
completion of an acceptable training course. NMFS would allow three 
weeks to approve PSOs from the time that the necessary information is 
received by NMFS after which any PSOs that meet the minimum 
requirements would automatically be considered approved.
    Some Dominion Energy activities may require the use of PAM, which 
would necessitate the employment of at least one PAM operator on duty 
at any given time. PAM operators would be required to meet several of 
the specified requirements described above for PSOs, including: 2, 4, 
6b-e, 8, 9, 10, and 11. Furthermore, PAM operators would be required to 
complete a specialized training for operating PAM systems and must 
demonstrate familiarity with the PAM system on which they would be 
working.
    PSOs would be able to act as both acoustic and visual observers for 
the project if the individual(s) demonstrates that they have had the 
required level and appropriate training and experience to perform each 
task. However, a single individual would not be allowed to concurrently 
act in both roles or exceed work hours, as specified in #4 above.
    Dominion Energy's personnel and PSOs would also be required to use 
available sources of information on North Atlantic right whale presence 
to aid in monitoring efforts. This includes:
    1. Daily monitoring of the Right Whale Sightings Advisory System;
    2. Consulting of the WhaleAlert app; and,
    3. Monitoring of the Coast Guard's VHF Channel 16 throughout the 
day to receive notifications of any sightings and information 
associated with any Dynamic Management Areas to plan construction 
activities and vessel routes, if practicable, to minimize the potential 
for co-occurrence with North Atlantic right whales.
    Additionally, whenever multiple project-associated vessels (of any 
size; e.g., construction survey, crew transfer) are operating 
concurrently, any visual observations of ESA-listed marine mammals must 
be communicated to PSOs and vessel captains associated with other 
vessels to increase situational awareness.
    The following are proposed monitoring and reporting measures that 
NMFS would require specific to each construction activity:

WTG and OSS Foundation Installation

    Dominion Energy would be required to implement the following 
monitoring procedures during all impact pile driving of WTG and OSS 
foundations.
    During all observations associated with pile driving (vibratory 
and/or impact), PSOs would use magnification (7x) binoculars and the 
naked eye to search continuously for marine mammals. At least one PSO 
would be located on the foundation pile driving vessel and a secondary 
dedicated-PSO vessel. These PSOs must be equipped with Big Eye 
binoculars (e.g., 25 x 50; 2,7 view angle; individual ocular focus; 
height control) of appropriate quality. These would be pedestal-mounted 
on the deck at the most appropriate vantage point that provides optimal 
sea surface observation and PSO safety.
    Dominion Energy would be required to have a minimum of four PSOs 
actively observing marine mammals before, during, and after (specific 
times described below) the installation of foundation piles (monopiles 
and pin piles for jacket foundations). At least two PSOs must be 
actively observing on the pile driving vessel while at least two PSOs 
are actively observing on a secondary, PSO-dedicated vessel. 
Concurrently, at least one acoustic PSO (i.e., PAM operator) must be 
actively monitoring for marine mammals before, during and after impact 
pile driving.
    As described in the Proposed Mitigation section, if the minimum 
visibility zone cannot be visually monitored at all times, pile driving 
operations may not commence or, if active, must shutdown, unless 
Dominion Energy determines shutdown is not practicable due to imminent 
risk of injury or loss of life to an individual, pile refusal, or pile 
instability.
    To supplement visual observation efforts, Dominion Energy would 
utilize at least one PAM operator before, during, and after pile 
installation. This PAM operator would assist the PSOs in ensuring full 
coverage of the clearance and shutdown zones. All on-duty visual PSOs 
would remain in contact with the on-duty PAM operator, who would 
monitor the PAM systems for acoustic detections of marine mammals in 
the area. In some cases, the PAM operator and workstation may be 
located onshore or they may be located on a vessel. In either 
situation, PAM operators would maintain constant and clear 
communication with visual PSOs on duty regarding detections of marine 
mammals that are approaching or within the applicable zones related to 
impact pile driving. Dominion Energy would utilize PAM to acoustically 
monitor the clearance and shutdown zones (and beyond for situational 
awareness), and would record all detections of marine mammals and 
estimated distance, when possible, to the activity (noting whether they 
are in the Level A harassment or Level B harassment zones). To 
effectively utilize PAM, Dominion Energy would implement the following 
protocols:
     PAM operators would be stationed on at least one of the 
dedicated monitoring vessels in addition to the PSOs, or located 
remotely/onshore.
     All PAM operators must be NMFS-approved, third party 
contractors. PAM operators would have completed specialized training 
for operating PAM systems prior to the start of monitoring activities, 
including identification of species-specific mysticete vocalizations 
(e.g., North Atlantic right whales). The PAM operator must demonstrate 
that they have prior experience with similar acoustic projects and/or 
completed specialized training for operating PAM systems and detecting 
and identifying Atlantic Ocean marine mammals sounds.
     Where localization of sounds or deriving bearings and 
distance are proposed, the PAM operators need to have demonstrated 
experience in using this technique.
     PAM operators must demonstrate experience with relevant 
acoustic software and equipment.
     PAM operators must have the qualifications and relevant 
experience/training to safely deploy and retrieve equipment and program 
the software, as necessary.
     PAM operators must be able to test software and hardware 
functionality prior to operation.
     PAM operators must have evaluated their acoustic detection 
software using the PAM Atlantic baleen whale annotated data set 
available through the National Centers for Environmental Information 
(NCEI; https://www.ncei.noaa.gov/) and provide evaluation/performance 
metric.
    The PAM operator(s) on-duty would monitor the PAM systems for 
acoustic detections of marine mammals that are vocalizing in the area. 
Any detections would be conveyed to the PSO team and any PSO sightings 
would be conveyed to the PAM operator for awareness purposes, and to 
identify if mitigation is to be triggered. For real-time PAM systems, 
at least one PAM operator would be designated to monitor each system by 
viewing data or data products that are streamed in real-time or near 
real-time to a computer workstation and monitor located on a project 
vessel or onshore. The PAM operator would

[[Page 28748]]

inform the Lead PSO on duty of marine mammal detections approaching or 
within applicable ranges of interest to the pile driving activity via 
the data collection software system (i.e., Mysticetus or similar 
system), who would be responsible for requesting that the designated 
crew member implement the necessary mitigation procedures (i.e., delay 
or shutdown). Acoustic monitoring would complement visual monitoring at 
all times and would cover an area of at least the Level B harassment 
zone around each foundation.
    All PSOs and PAM operators would be required to begin monitoring 60 
minutes prior to and during all impact pile driving and for 30 minutes 
after impact driving. However, PAM operators must review acoustic data 
from the previous 24 hours as well. As described in the Proposed 
Mitigation section, pile driving of monopiles and pin piles would only 
commence when the minimum visibility zone (extending 2.0 km from the 
pile, based on NMFS' proposed distance) is fully visible (e.g., not 
obscured by darkness, rain, fog, etc.) and the clearance zones are 
clear of marine mammals for at least 30 minutes, as determined by the 
Lead PSO, immediately prior to the initiation of impact pile driving.
    For North Atlantic right whales, any visual (regardless of 
distance) or acoustic detection would trigger a delay to the 
commencement of pile driving. In the event that a large whale is 
sighted or acoustically detected that cannot be confirmed as a non-
North Atlantic right whale species, it must be treated as if it were a 
North Atlantic right whale. Following a shutdown, monopile/pin pile 
installation may not recommence until the minimum visibility zone is 
fully visible and the clearance zone is clear of marine mammals for 30 
minutes and no marine mammals have been detected acoustically within 
the PAM clearance zone for 30 minutes.
    During the time period in which Dominion Energy would be allowed to 
pile driving (May 1-October 31), North Atlantic right whales are most 
likely to occur in May. Dominion Energy has proposed additional 
enhanced monitoring measures to supplement PSO and PAM operators during 
the month of May (per the May Pile Driving Memo Dominion Energy 
submitted to NMFS on March 23, 2023 and which can be found on NMFS' 
website), including the use of drones equipped with infrared technology 
(referred to as autonomous vehicles, remote operated vehicles in 
Dominion Energy's PSMMP), additional PSO vessels on-site, aerial 
surveys, and/or 24-hour PAM use. These measures, as proposed by 
Dominion Energy, would not prevent or replace other proposed monitoring 
measures (i.e., PSOs and/or PAM operators). Instead, these additional 
measures would serve to complement and strengthen other monitoring 
approaches. Dominion Energy would seek to use autonomous or remotely 
operated vehicles (i.e., drones) that may use infrared technology; then 
the use of additional PSOs for enhanced coverage; and then aerial 
surveys. While Dominion Energy proposed these measures, they have not 
committed to implementing these measures in order to proceed with 
foundation installation in May. Hence, NMFS is not proposing to require 
them here. However, we describe requirements for drone use below in the 
case that Dominion Energy does employ drones in addition to the 
previously described PSO and acoustic monitoring requirements.
    If drones are deployed during May foundation installation 
activities Dominion Energy would undertake monitoring approaches in a 
way that would ensure no additional behavioral harassment or impacts on 
marine mammals would occur. While specifics on Dominion Energy's drone 
strategy was not provided in either the ITA application, nor the PSMMP, 
given ongoing and planned testing to occur in 2023, NMFS would require 
that:
     All drone operators and associated drone crews would be 
fully trained, qualified, and would operate in compliance with current 
Federal Aviation Administration (FAA), Federal, State, and local 
standards and would be operated in accordance with 14 CFR part 107 
(Small Unmanned Aircraft Systems, Docket FAA-2015-0150, Amdt. 107-1, 81 
FR 42209, June 28, 2016, unless otherwise noted);
     An appropriate number of drone operators and crews would 
be utilized, with some personnel operating the drone and others 
monitoring the instrumentation for marine mammal identification in 
real-time (i.e., would be trained and certified PSOs);
     All monitoring crews (i.e., PSOs operating drones) would 
meet the requirements and qualifications previously described in this 
proposed rulemaking;
     All drones would maintain appropriate altitudes and 
minimize maneuvers or circling activities that may incur behavioral 
harassment to marine mammals and appropriate distances (to be decided 
based on the 2023 testing by Dominion Energy) would be required if 
mothers and calves are sighted; and
     All drone visual observations would be incorporated into 
the standard reporting requirements, described later on in this 
proposed rulemaking.
    The advancement of additional monitoring measures have the 
potential to enhance capabilities in situations where there is limited 
visibility. However, implementation of such strategies would require 
additional testing by Dominion Energy (via 2023 trials) and additional 
discussions between NMFS.
    For all foundation installation activities, Dominion Energy must 
prepare and submit a Pile Driving and Marine Mammal Monitoring Plan 
(including information related to the proposed enhanced monitoring 
measures described above) to NMFS for review and approval at least 180 
days before the start of any pile driving. The plans must include final 
pile driving project design (e.g., number and type of piles, hammer 
type, noise abatement systems, anticipated start date, etc.) and all 
information related to PAM PSO monitoring protocols for pile-driving 
and visual PSO protocols for all activities.

Cable Landfall Activities--Temporary Cofferdams

    Dominion Energy would be required to implement the following 
procedures during all vibratory pile driving activities associated with 
the installation and removal of temporary cofferdams.
    During all observation periods related to vibratory pile driving, 
PSOs must use standard handheld (7x) binoculars and the naked eye to 
search continuously for marine mammals. Dominion Energy would be 
required to have a minimum of two PSOs on active duty during any 
installation and removal activities related to temporary cofferdams. 
These PSOs would always be located at the best vantage point(s) on the 
vibratory pile driving platform or secondary platform in the immediate 
vicinity of the primary platforms in order to ensure that appropriate 
visual coverage is available of the entire visual clearance zone and as 
much of the Level B harassment zone as possible. NMFS would not require 
the use of PAM for these activities.
    PSOs would monitor the clearance zone for the presence of marine 
mammals for 30 minutes before, throughout the installation of the 
piles, and for 30 minutes after the activities have ceased. 
Installation may only commence when visual clearance zones are fully 
visible (e.g., not obscured by darkness, rain, fog, etc.) and clear of 
marine mammals, as determined by the

[[Page 28749]]

Lead PSO, for at least 30 minutes immediately prior to initiation of 
vibratory pile driving.

Cable Landfall Activities--Temporary Goal Posts

    Dominion Energy would be required to implement the following 
procedures during all impact pile driving activities associated with 
the installation of temporary goal posts. These requirements generally 
mirror the requirements described above for temporary cofferdams.
    During all observation periods related to impact pile driving, PSOs 
must use standard handheld (7x) binoculars and the naked eye to search 
continuously for marine mammals. Dominion Energy would be required to 
have a minimum of two PSOs on active duty during any installation 
activities related to temporary goal posts. These PSOs would always be 
located at the best vantage point(s) on the impact pile driving 
platform or secondary platform in the immediate vicinity of the primary 
platforms in order to ensure that appropriate visual coverage is 
available of the entire visual clearance zone and as much of the Level 
B harassment zone as possible. NMFS would not require the use of PAM 
for these activities.
    PSOs would monitor the clearance zone for the presence of marine 
mammals for 30 minutes before, throughout the installation of the pipe 
piles, and for 30 minutes after the activities have ceased. 
Installation may only commence when visual clearance zones are fully 
visible (e.g., not obscured by darkness, rain, fog, etc.) and clear of 
marine mammals, as determined by the Lead PSO, for at least 30 minutes 
immediately prior to initiation of impact pile driving.

HRG Surveys

    Dominion Energy would be required to implement the following 
procedures during all HRG surveys.
    During all observation periods, PSOs must use standard handheld 
(7x) binoculars and the naked eye to search continuously for marine 
mammals.
    Between four and six PSOs would be present on every 24-hour survey 
vessel, and two to three PSOs would be present on every 12-hour survey 
vessel. Dominion Energy would be required to have at least one PSO on 
active duty during HRG surveys that are conducted during daylight hours 
(i.e., from 30 minutes prior to sunrise through 30 minutes following 
sunset) and at least two PSOs during HRG surveys that are conducted 
during nighttime hours.
    All PSOs would begin monitoring 30 minutes prior to the activation 
of boomers, sparkers, or CHIRPs; throughout use of these acoustic 
sources, and for 30 minutes after the use of the acoustic sources has 
ceased.
    Given that multiple HRG vessels may be operating concurrently, any 
observations of marine mammals would be required to be communicated to 
PSOs on all nearby survey vessels.
    Ramp-up of boomers, sparkers, and CHIRPs would only commence when 
visual clearance zones are fully visible (e.g., not obscured by 
darkness, rain, fog, etc.) and clear of marine mammals, as determined 
by the Lead PSO, for at least 30 minutes immediately prior to 
initiation of survey activities utilizing the specified acoustic 
sources.
    During daylight hours when survey equipment is not operating, 
Dominion Energy would ensure that visual PSOs conduct, as rotation 
schedules allow, observations for comparison of sighting rates and 
behavior with and without use of the specified acoustic sources. Off-
effort PSO monitoring must be reflected in the monthly PSO monitoring 
reports.

Marine Mammal Passive Acoustic Monitoring

    As described previously, Dominion Energy would be required to 
utilize a PAM system to supplement visual monitoring for all foundation 
installation activities, inclusive of vibratory and impact hammer 
installation. Training and qualified PAM operators would monitor the 
PAM systems. PAM operators may be on watch for a maximum of four 
consecutive hours followed by a break of at least two hours between 
watches. Again, PSOs can act as PAM operators or visual PSOs (but not 
simultaneously) as long as they demonstrate that their training and 
experience are sufficient to perform each task. The PAM system must be 
monitored by a minimum of one PAM operator beginning at least 60 
minutes prior to the initiation of soft-start of foundation piles, at 
all times during installation, and for 30 minutes after pile driving 
has ceased. To further aid in detections of North Atlantic right whales 
during the highest occurrence month (May) during the construction 
period (and as described above for monitoring during WTG and OSS 
foundation Installation), PAM would be implemented 24-hours prior to 
foundation activities.
    PAM operators would monitor the signals from the hydrophones in 
both real-time using headphones and visually via the outputs on a 
computer monitor. PAM operators must immediately communicate all 
detections of marine mammals at any distance (i.e., not limited to the 
Level B harassment zones) to visual PSOs, including any determination 
regarding species identification, distance, and bearing and the degree 
of confidence in the determination. Based on the information provided 
by the PAM operator, the Lead PSO on duty would ensure that the 
appropriate mitigation measures are implemented, if determined to be 
necessary. A PAM detection alone, even without a visual confirmation 
that a marine mammal is within a relevant clearance and/or shutdown 
zone, would trigger mitigation measures, such as a delay or the 
shutdown of pile driving activities (if safe to do so). Additionally, 
PAM detections of North Atlantic right whales, even without a visual 
detection, would trigger the appropriate mitigation measures.
    PAM systems may be used for real-time mitigation monitoring. The 
PAM system would be, at a minimum, capable of detecting animals at 
least 5 km away from the pile driving location. The PAM system would 
offer real-time detections of low-frequency cetaceans with a targeted 
frequency range of 20 Hz to 1,500 Hz, with a specific focus on a system 
capable of monitoring the bandwidth for North Atlantic right whales 
(65-400 Hz; corresponding to information provided in Van Parijs et al. 
(2021)). The requirement for real-time detection and localization 
limits the types of PAM technologies that can be used to those systems 
that are either cabled, satellite, or radio-linked. It is most likely 
that Dominion Energy would deploy fixed surface buoys and/or gliding 
autonomous vehicle PAM devices. The system chosen will dictate the 
design and protocols of the PAM operations. Dominion Energy is not 
considering bottom-mounted, fixed cabled PAM systems, in part due to 
the ability of most of these systems to record data archivally rather 
than in real-time or near-real-time. Towed systems, while being 
considered, are not preferred as they could be easily masked by vessel 
noise. For a review of the PAM systems Dominion Energy is considering, 
see section 7.3 and 7.4 of the PSMMP included as a supplement to 
Dominion Energy's ITA application.
    At this stage, Dominion Energy has not chosen the appropriate and 
final PAM systems for the CVOW-C project. However, when an appropriate 
system or configuration of systems is chosen, a Passive Acoustic 
Monitoring (PAM) Plan must be submitted to NMFS for review and approval 
at least 180 days prior to the planned start of foundation 
installations. PAM should follow standardized measurement, processing 
methods, reporting metrics, and metadata standards for offshore wind

[[Page 28750]]

(Van Parijs et al., 2021). The plan must describe all proposed PAM 
equipment, procedures, and protocols. However, NMFS considers PAM usage 
for every project on a case-by-case basis and would continue 
discussions with Dominion Energy regarding selection of the PAM system 
that is most appropriate for the proposed project. The authorization to 
take marine mammals would be contingent upon NMFS' approval of the PAM 
Plan.

Acoustic Monitoring for Sound Field and Harassment Isopleth 
Verification (SFV)

    During the installation (inclusive of both vibratory and impact 
pile driving approaches) of the first three WTG monopile foundations 
and all three OSSs using jacket foundations, Dominion Energy must 
empirically determine source levels, the ranges to the isopleths 
corresponding to the Level A harassment and Level B harassment 
thresholds, and the transmission loss coefficient(s). Dominion Energy 
may also estimate ranges to the Level A harassment and Level B 
harassment isopleths by extrapolating from in situ measurements 
conducted at several distances from the monopile and pin piles in each 
OSS being driven. Dominion Energy must measure received levels at a 
standard distance of 750 m from the monopile and pin piles in each OSS 
and at both the presumed modeled Level A harassment and Level B 
harassment isopleth ranges or an alternative distance(s) as agreed to 
in the SFV Plan. In addition to the 750 m distance, Dominion Energy has 
also proposed to monitor at 2,500 m and 5,000 m from the pile, as well 
as the extent of the modeled Level B harassment zone to verify the 
accuracy of the modeled zones.
    If acoustic field measurements collected during installation of the 
WTG monopiles and OSS foundations indicates ranges to the isopleths 
corresponding to Level A harassment and Level B harassment thresholds 
are greater than the ranges predicted by modeling (assuming 10-dB 
attenuation), Dominion Energy must implement additional noise 
attenuation measures prior to installing the next WTG monopile or OSS 
jacket foundation. Dominion Energy has also proposed to monitor and 
collect acoustic information on a subsequent monopile in the event that 
obtained technical information indicates a monopile would produce a 
larger sound field than previously monitored. Initial additional 
measures may include improving the efficacy of the implemented noise 
mitigation technology (e.g., BBC, dBBC) and/or modifying the piling 
schedule to reduce the sound source. Each sequential modification would 
be evaluated empirically by acoustic field measurements. In the event 
that field measurements indicate ranges to isopleths corresponding to 
Level A harassment and Level B harassment thresholds are greater than 
the ranges predicted by modeling (assuming 10-dB attenuation), NMFS may 
expand the relevant harassment, clearance, and shutdown zones and 
associated monitoring protocols. If harassment zones are expanded 
beyond an additional 1,500 m, additional PSOs would be deployed on 
additional platforms with each observer responsible for maintaining 
watch in no more than 180[deg] and of an area with a radius no greater 
than 1,500 m.
    If acoustic measurements indicate that ranges to isopleths 
corresponding to the Level A harassment and Level B harassment 
thresholds are less than the ranges predicted by modeling (assuming 10-
dB attenuation), Dominion Energy may request a modification of the 
clearance and shutdown zones for pile driving of WTG monopiles and OSS 
foundation pin piles. For NMFS to consider a modification request, 
Dominion Energy will have had to conduct SFV on three or more WTG 
monopiles and two full OSS jacket foundations (8 total pin piles), thus 
far, to verify that zone sizes are consistently smaller than those 
predicted by modeling (assuming 10-dB attenuation). In addition, if a 
subsequent monopile installation location is selected that was not 
represented by previous three locations (i.e., substrate composition, 
water depth), SFV would be required. Furthermore, if pile driving of 
WTG foundations occurs across different seasons from the season the 
first monopile was installed in (i.e., the first monopile was driven in 
the spring and as pile driving would also occur in the fall, acoustic 
measurements for the pile driven in the fall would also be required to 
occur), Dominion Energy has proposed, for comparison, to collect 
acoustic measurements on these piles as well.
    Upon receipt of an interim SFV report, NMFS may adjust zones (i.e., 
Level A harassment, Level B harassment, clearance, shutdown, and/or 
minimum visibility zone) to reflect SFV measurements. The shutdown and 
clearance zones for pile driving would be equivalent to the measured 
range to the Level A harassment isopleths plus 10 percent (shutdown 
zone) and 20 percent (clearance zone), rounded up to the nearest 100 m 
for PSO clarity. The minimum visibility zone would be based on the 
largest measured distance to the Level A harassment isopleth for large 
whales. Regardless of SFV, a North Atlantic right whale detected at any 
distance by PSOs would continue to result in a delay to the start of 
pile driving. Similarly, if pile driving has commenced, shutdown would 
be called for in the event a North Atlantic right whale is observed at 
any distance. That is, the visual clearance and shutdown criteria for 
North Atlantic right whales would not change, regardless of field 
acoustic measurements. The Level B harassment zone would be equal to 
the largest measured range to the Level B harassment isopleth.
    The SFV plan must also include how operational noise from the wind 
farm would be monitored. Dominion Energy would be required to estimate 
source levels based on measurements in the near and far-field at a 
minimum of three locations from each foundation monitored. These data 
must be used to also identify estimated transmission loss rates. 
Operational parameters (e.g., direct drive/gearbox information, turbine 
rotation rate) as well as sea state conditions and information on 
nearby anthropogenic activities (e.g., vessels transiting or operating 
in the area) must be reported.
    Dominion Energy must submit a SFV Plan at least 180 days prior to 
the planned start of impact pile driving activities. The plan must 
describe how Dominion Energy would ensure that the first three WTG 
monopile and OSS jacket (using pin piles) foundation installation sites 
selected for SFV are representative of the rest of the monopile and pin 
pile installation sites. Dominion Energy must include information on 
how additional sites/scenarios would be selected for SFV should it be 
determined that these sites/scenarios are not representative of all 
other monopile installation sites. The plan must also include the 
methodology for collecting, analyzing, and preparing SFV data for 
submission to NMFS. The plan must describe how the effectiveness of the 
sound attenuation methodology would be evaluated based on the results. 
Dominion Energy must also provide, as soon as they are available but no 
later than 48 hours after each installation, the initial results of the 
SFV measurements to NMFS in an interim report after each monopile for 
the first three piles.

Reporting

    Prior to any construction activities occurring, Dominion Energy 
would provide a report to NMFS (at [email protected] and 
[email protected])

[[Page 28751]]

documenting that all required training for Dominion Energy personnel 
(i.e., vessel crews, vessel captains, PSOs, and PAM operators) has been 
completed. Dominion Energy has also proposed to contact both BOEM and 
NMFS within 24-hour of the commencement of pile driving activities for 
the year and again within 24 hours of the completion of the pile 
driving activities for that year (based on May 1st through October 
31st).
    NMFS would require standardized and frequent reporting from 
Dominion Energy during the life of the proposed regulations and LOA. 
All data collected relating to the Dominion Energy project would be 
recorded using industry-standard software (e.g., Mysticetus or a 
similar software) installed on field laptops and/or tablets. Dominion 
Energy would be required to submit weekly, monthly and annual reports 
as described below. During activities requiring PSOs, the following 
information would be collected and reported related to the activity 
being conducted:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Watch status (i.e., sighting made by PSO on/off effort, 
opportunistic, crew, alternate vessel/platform);
     PSO who sighted the animal;
     Time of sighting;
     Weather parameters (e.g., wind speed, percent cloud cover, 
visibility);
     Water conditions (e.g., sea state, tide state, water 
depth);
     All marine mammal sightings, regardless of distance from 
the construction activity;
     Species (or lowest possible taxonomic level possible);
     Pace of the animal(s);
     Estimated number of animals (minimum/maximum/high/low/
best);
     Estimated number of animals by cohort (e.g., adults, 
yearlings, juveniles, calves, group composition, etc.);
     Description (i.e., as many distinguishing features as 
possible of each individual seen, including length, shape, color, 
pattern, scars or markings, shape and size of dorsal fin, shape of 
head, and blow characteristics);
     Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling) and observed 
changes in behavior, including an assessment of behavioral responses 
thought to have resulted from the specific activity;
     Animal's closest distance and bearing from the pile being 
driven or specified HRG equipment and estimated time spent within the 
Level A harassment and/or Level B harassment zones;
     Construction activity at time of sighting (e.g., vibratory 
installation/removal, impact pile driving, HRG survey), use of any 
noise abatement device(s), and specific phase of activity (e.g., ramp-
up of HRG equipment, HRG acoustic source on/off, soft start for pile 
driving, active pile driving, etc.);
     Description of any mitigation-related action implemented, 
or mitigation-related actions called for but not implemented, in 
response to the sighting (e.g., delay, shutdown, etc.) and time and 
location of the action; and
     Other human activity in the area.
    For all real-time acoustic detections of marine mammals, the 
following must be recorded and included in weekly, monthly, annual, and 
final reports:
    1. Location of hydrophone (latitude & longitude; in Decimal 
Degrees) and site name;
    2. Bottom depth and depth of recording unit (in meters);
    3. Recorder (model & manufacturer) and platform type (i.e., bottom-
mounted, electric glider, etc.), and instrument ID of the hydrophone 
and recording platform (if applicable);
    4. Time zone for sound files and recorded date/times in data and 
metadata (in relation to Universal Coordinated Time (UTC); i.e., 
Eastern Standard Time (EST) time zone is UTC-5);
    5. Duration of recordings (start/end dates and times; in ISO 8601 
format, yyyy-mm-ddTHH:MM:SS.sssZ);
    6. Deployment/retrieval dates and times (in ISO 8601 format);
    7. Recording schedule (must be continuous);
    8. Hydrophone and recorder sensitivity (in dB re. 1 [mu]Pa);
    9. Calibration curve for each recorder;
    10. Bandwidth/sampling rate (in Hz);
    11. Sample bit-rate of recordings; and
    12. Detection range of equipment for relevant frequency bands (in 
meters).
    For each detection the following information must be noted:
    13. Species identification (if possible);
    14. Call type and number of calls (if known);
    15. Temporal aspects of vocalization (date, time, duration, etc., 
date times in ISO 8601 format);
    16. Confidence of detection (detected, or possibly detected);
    17. Comparison with any concurrent visual sightings;
    18. Location and/or directionality of call (if determined) relative 
to acoustic recorder or construction activities;
    19. Location of recorder and construction activities at time of 
call;
    20. Name and version of detection or sound analysis software used, 
with protocol reference;
    21. Minimum and maximum frequencies viewed/monitored/used in 
detection (in Hz); and
    22. Name of PAM operator(s) on duty.
    If a North Atlantic right whale is detected, data shall be 
submitted to [email protected] using the NMFS Passive Acoustic 
Reporting System Metadata and Detection data spreadsheets (https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-system-templates) as soon as feasible but no longer than 24 hours after 
the detection. Submit the completed data templates to 
[email protected]. The full acoustic species Detection data, 
Metadata and GPS data records, from real-time data, must be submitted 
within 90 days via the ISO standard metadata forms available on the 
NMFS Passive Acoustic Reporting System website (https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-system-template). Submit the completed data templates to 
[email protected]. Full detection data and metadata must be 
submitted monthly on the 15th of every month for the previous month via 
the webform on the NMFS North Atlantic right whale Passive Acoustic 
Reporting System website (https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-system-templates).
    If a North Atlantic right whale is observed at any time by PSOs or 
personnel on or in the vicinity of any impact or vibratory pile-driving 
vessel, dedicated PSO vessel, construction survey vessel, or during 
vessel transit, Dominion Energy must immediately report sighting 
information to the NMFS North Atlantic Right Whale Sighting Advisory 
System (866) 755-6622, to the U.S. Coast Guard via channel 16, and 
through the WhaleAlert app (https://www.whalealert.org/) as soon as 
feasible but no longer than 24 hours after the sighting. Information 
reported must include, at a minimum: time of sighting, location, and 
number of North Atlantic right whales observed.
    SFV Interim Report--Dominion Energy would be required to provide, 
as soon as they are available but no later than 48 hours after each 
installation, the initial results of SFV measurements to NMFS in an 
interim report after each monopile for the first three piles and any 
subsequent piles monitored.
    Weekly Report--Dominion Energy would be required to compile and 
submit weekly PSO, PAM, and SFV reports to NMFS

[[Page 28752]]

([email protected]) that document the daily start and 
stop of all pile driving or HRG survey activities, the start and stop 
of associated observation periods by PSOs, details on the deployment of 
PSOs, a record of all detections of marine mammals (acoustic and 
visual), any mitigation actions (or if mitigation actions could not be 
taken, provide reasons why), and details on the noise abatement 
system(s) used and its performance. Weekly reports would be due on 
Wednesday for the previous week (Sunday-Saturday). The weekly report 
would also identify which turbines become operational and when (a map 
must be provided). Once all foundation pile installation is complete, 
weekly reports would no longer be required.
    Monthly Report--Dominion Energy would be required to compile and 
submit monthly reports to NMFS (at [email protected] and 
[email protected]) that include a summary of all 
information in the weekly reports, including project activities carried 
out in the previous month, vessel transits (number, type of vessel, and 
route), number of piles installed, all detections of marine mammals, 
and any mitigative actions taken. Monthly reports would be due on the 
15th of the month for the previous month. The monthly report would also 
identify which turbines become operational and when (a map must be 
provided). Once foundation pile installation is complete, monthly 
reports would no longer be required.
    Annual Report--Dominion Energy would be required to submit an 
annual PSO, PAM, and SFV summary report to NMFS (at 
[email protected] and [email protected]) no later 
than 90 days following the end of a given calendar year describing, in 
detail, all of the information required in the monitoring section 
above. A final annual report would be prepared and submitted within 30 
calendar days following receipt of any NMFS comments on the draft 
report. If no comments were received from NMFS within 60 calendar days 
of NMFS' receipt of the draft report, the report would be considered 
final.
    Final Report--Dominion Energy must submit its draft final report(s) 
to NMFS (at [email protected] and [email protected]) 
on all visual and acoustic monitoring conducted under the LOA within 90 
calendar days of the completion of activities occurring under the LOA. 
A final report must be prepared and submitted within 30 calendar days 
following receipt of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 calendar days of NMFS' 
receipt of the draft report, the report shall be considered final.

Situational Reporting

    Specific situations encountered during the development of the 
Dominion Energy project would require reporting. These situations and 
the relevant procedures include:
     If a large whale is detected during vessel transit, the 
following information must be recorded and reported:
    a. Time, date, and location;
    b. The vessel's activity, heading, and speed;
    c. Sea state, water depth, and visibility;
    d. Marine mammal identification to the best of the observer's 
ability (e.g., North Atlantic right whale, whale, dolphin, seal);
    e. Initial distance and bearing to marine mammal from vessel and 
closest point of approach; and,
    f. Any avoidance measures taken in response to the marine mammal 
sighting.
     If a sighting of a stranded, entangled, injured, or dead 
marine mammal occurs, the sighting would be reported to NMFS OPR, the 
NMFS Greater Atlantic Regional Fisheries Office (GARFO) Marine Mammal 
and Sea Turtle Stranding & Entanglement Hotline (866-755-6622), and the 
U.S. Coast Guard within 24 hours. If the injury or death was caused by 
a project activity, Dominion Energy must immediately cease all 
activities until NMFS OPR is able to review the circumstances of the 
incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the LOA. NMFS may 
impose additional measures to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. Dominion Energy may not 
resume their activities until notified by NMFS. The report must include 
the following information:
    a. Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    b. Species identification (if known) or description of the 
animal(s) involved;
    c. Condition of the animal(s) (including carcass condition if the 
animal is dead);
    d. Observed behaviors of the animal(s), if alive;
    e. If available, photographs or video footage of the animal(s); and
    f. General circumstances under which the animal was discovered.
     In the event of a vessel strike of a marine mammal by any 
vessel associated with the CVOW-C project, Dominion Energy shall 
immediately report the strike incident to the NMFS OPR and the GARFO 
within and no later than 24 hours. Dominion Energy must immediately 
cease all activities until NMFS OPR is able to review the circumstances 
of the incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the LOA. NMFS may 
impose additional measures to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. Dominion Energy may not 
resume their activities until notified by NMFS. The report must include 
the following information:
    a. Time, date, and location (latitude/longitude) of the incident;
    b. Species identification (if known) or description of the 
animal(s) involved;
    c. Vessel's speed during and leading up to the incident;
    d. Vessel's course/heading and what operations were being conducted 
(if applicable);
    e. Status of all sound sources in use;
    f. Description of avoidance measures/requirements that were in 
place at the time of the strike and what additional measures were 
taken, if any, to avoid strike;
    g. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, visibility) immediately preceding the 
strike;
    h. Estimated size and length of animal that was struck;
    i. Description of the behavior of the marine mammal immediately 
preceding and following the strike;
    j. If available, description of the presence and behavior of any 
other marine mammals immediately preceding the strike;
    k. Estimated fate of the animal (e.g., dead, injured but alive, 
injured and moving, blood or tissue observed in the water, status 
unknown, disappeared); and
    l. To the extent practicable, photographs or video footage of the 
animal(s).

Sound Monitoring Reporting

    As described previously, Dominion Energy would be required to 
provide the initial results of SFV (including measurements) to NMFS in 
interim reports after each monopile installation for the first three 
piles (and any subsequent piles) as soon as they are available, but no 
later than 48 hours after each installation. In addition to in situ 
measured ranges to the Level A harassment and Level B harassment

[[Page 28753]]

isopleths, the acoustic monitoring report must include: hammer energies 
(pile driving), SPLpeak, SPLrms that contains 90 
percent of the acoustic energy, single strike sound exposure level, 
integration time for SPLrms, and 24-hour cumulative SEL 
extrapolated from measurements. The sound levels reported must be in 
median and linear average (i.e., average in linear space), and in dB. 
All these levels must be reported in the form of median, mean, max, and 
minimum. The SEL and SPL power spectral density and one-third octave 
band levels (usually calculated as decidecade band levels) at the 
receiver locations should be reported. The acoustic monitoring report 
must also include: a description of the SFV PAM hardware and software, 
including software version used, calibration data, bandwidth capability 
and sensitivity of hydrophone(s), any filters used in hardware or 
software, any limitations with the equipment, a description of the 
hydrophones used, hydrophone and water depth, distance to the pile 
driven, sediment type at the recording location, and local 
environmental conditions (e.g., wind speed). In addition, pre- and 
post-activity ambient sound levels (broadband and/or within frequencies 
of concern) should be reported. Finally, the report must include a 
description of the noise abatement system and operational parameters 
(e.g., bubble flow rate, distance deployed from the pile, etc.), and 
any action taken to adjust the noise abatement system. Final results of 
SFV must be submitted as soon as possible, but no later than within 90 
days following completion of impact pile driving of monopiles.

Adaptive Management

    The regulations governing the take of marine mammals incidental to 
Dominion Energy's construction activities would contain an adaptive 
management component. The reporting requirements associated with this 
rule are designed to provide NMFS with monitoring data throughout the 
life of the regulations that can inform potential consideration of 
whether any changes to mitigation or monitoring are appropriate. The 
use of adaptive management allows NMFS to consider new information from 
different sources to determine (with input from Dominion Energy 
regarding practicability) if mitigation or monitoring measures should 
be modified (including additions or deletions). Mitigation measures 
could be modified if new data suggests that such modifications would 
have a reasonable likelihood of reducing adverse effects to marine 
mammals and if the measures are practicable.
    The following are some of the possible sources of applicable data 
to be considered through the adaptive management process: (1) Results 
from monitoring reports, as required by MMPA authorizations; (2) 
results from general marine mammal and sound research; and (3) any 
information which reveals that marine mammals may have been taken in a 
manner, extent, or number not authorized by these regulations or 
subsequent LOA. During the course of the rule, Dominion Energy (and 
other LOA-holders conducting offshore wind development activities) 
would be required to participate in one or more adaptive management 
meetings convened by NMFS and/or BOEM, in which the above information 
would be summarized and discussed in the context of potential changes 
to the mitigation or monitoring measures.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' by mortality, serious injury, and Level A harassment or Level 
B harassment, we consider other factors, such as the likely nature of 
any behavioral responses (e.g., intensity, duration), the context of 
any such responses (e.g., critical reproductive time or location, 
migration) as well as effects on habitat and the likely effectiveness 
of mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    In the Estimated Take section, we identified the subset of 
potential effects that would be expected to qualify as takes under the 
MMPA and then identified the total number of takes by Level A 
harassment and Level B harassment that we estimate are reasonably 
expected to occur based on the methods described. The impact that any 
given take would have is dependent on many case-specific factors that 
need to be considered in the negligible impact analysis (e.g., the 
context of behavioral exposures such as duration or intensity of a 
disturbance, the health of impacted animals, the status of a species 
that incurs fitness-level impacts to individuals, etc.). In this rule, 
we evaluate the likely impacts of the enumerated harassment takes that 
are proposed for authorization in the context of the specific 
circumstances surrounding these estimated takes. We also collectively 
evaluate this information as well as other more taxa-specific 
information and mitigation measure effectiveness in group-specific 
discussions that support our negligible impact conclusions for each 
stock. As also described above, no serious injury or mortality is 
expected or proposed for authorization for any species or stock.
    The Description of the Specified Activities section describes the 
specified activities proposed by Dominion Energy that may result in 
take of marine mammals and an estimated schedule for conducting those 
activities. Dominion Energy has provided a realistic construction 
schedule (e.g., Dominion Energy's schedule reflects the maximum number 
of piles they anticipate to be able to drive each month in which pile 
driving is authorized to occur), although, we recognize schedules may 
shift for a variety of reasons (e.g., weather or supply delays). 
However, the total number of take would not exceed the 5-year totals 
and maximum annual total in any given year indicated in Tables 27, 28, 
and 29, respectively.
    We base our analysis and negligible impact determination (NID) on 
the total number of takes that would be reasonably expected to occur 
and are proposed to be authorized in the 5-year LOA, if issued, and 
extensive qualitative consideration of other contextual factors that 
influence the degree of impact of the takes on the affected individuals 
and the number and context of the individuals affected. As stated 
before, the number of takes, both annual and 5-year total, alone are 
only a part of the analysis. To avoid repetition, we provide some 
general analysis in this Negligible Impact Analysis and Determination 
section that applies to all the species listed in Table 7, given that 
some of the anticipated effects of Dominion Energy's construction

[[Page 28754]]

activities on marine mammals are expected to be relatively similar in 
nature. Then, we subdivide into more detailed discussions for 
mysticetes, odontocetes, and pinnipeds, which have broad life history 
traits that support an overarching discussion of some factors 
considered within the analysis for those groups (e.g., habitat-use 
patterns, high-level differences in feeding strategies).
    Last, we provide a negligible impact determination for each species 
or stock, providing species or stock-specific information or analysis, 
where appropriate, for example, for North Atlantic right whales given 
their population status. Organizing our analysis by grouping species or 
stocks that share common traits or that would respond similarly to 
effects of Dominion Energy's proposed activities and then providing 
species- or stock-specific information allows us to avoid duplication 
while ensuring that we have analyzed the effects of the specified 
activities on each affected species or stock. It is important to note 
that in the group or species sections, we base our negligible impact 
analysis on the maximum annual take that is predicted under the 5-year 
rule; however, the majority of the impacts are associated with 
installation of the WTG and OSS foundations, which would occur largely 
within a two year period. The estimated take in the other years is 
expected to be notably less, which is reflected in the total take that 
would be allowable under the rule (see Tables 27, 28, and 29).
    As described previously, no serious injury or mortality is 
anticipated or proposed for authorization in this rule. The amount of 
harassment Dominion Energy has requested and NMFS is proposing to 
authorize is based on exposure models that consider the outputs of 
acoustic source and propagation models as well as consideration of 
other information such as group size and PSO data during previous HRG 
surveys. For all species, the amount of take proposed to be authorized 
represents the amount of Level A harassment and Level B harassment that 
could occur.

Behavioral Disturbance

    In general, NMFS anticipates that impacts on an individual that has 
been harassed are likely to be more intense when exposed to higher 
received levels and for a longer duration (though this is in no way a 
strictly linear relationship for behavioral effects across species, 
individuals, or circumstances) and less severe impacts result when 
exposed to lower received levels and for a shorter duration. However, 
there is also growing evidence of the importance of contextual factors, 
such as distance from a source in predicting marine mammal behavioral 
response to sound--i.e., sounds of a similar level emanating from a 
more distant source have been shown to be less likely to evoke a 
response of equal magnitude (e.g., DeRuiter and Doukara, 2012; Falcone 
et al., 2017). As described in the Potential Effects to Marine Mammals 
and their Habitat section, the intensity and duration of any impact 
resulting from exposure to Dominion Energy's activities is dependent 
upon a number of contextual factors including, but not limited to, 
sound source frequencies, whether the sound source is moving towards 
the animal, hearing ranges of marine mammals, behavioral state at time 
of exposure, status of individual exposed (e.g., reproductive status, 
age class, health) and an individual's experience with similar sound 
sources. Ellison et al. (2012) and Moore and Barlow (2013), among 
others, emphasize the importance of context (e.g., behavioral state of 
the animals, distance from the sound source) in evaluating behavioral 
responses of marine mammals to acoustic sources. Harassment of marine 
mammals may result in behavioral modifications (e.g., avoidance, 
temporary cessation of foraging or communicating, changes in 
respiration or group dynamics, masking) or may result in auditory 
impacts such as hearing loss. In addition, some of the lower level 
physiological stress responses (e.g., orientation or startle response, 
change in respiration, change in heart rate) discussed previously would 
likely co-occur with the behavioral modifications, although these 
physiological responses are more difficult to detect and fewer data 
exist relating these responses to specific received levels of sound. 
Takes by Level B harassment, then, may have a stress-related 
physiological component as well; however, we would not expect Dominion 
Energy's activities to produce conditions of long-term and continuous 
exposure to noise leading to long-term physiological stress responses 
in marine mammals that could affect reproduction or survival.
    In the range of potential behavioral effects that might be expected 
to be part of a response that qualifies as an instance of Level B 
harassment by behavioral disturbance (which by nature of the way it is 
modeled/counted, occurs within one day), the less severe end might 
include exposure to comparatively lower levels of a sound, at a greater 
distance from the animal, for a few or several minutes. A less severe 
exposure of this nature could result in a behavioral response such as 
avoiding an area that an animal would otherwise have chosen to move 
through or feed in for some amount of time, or breaking off one or a 
few feeding bouts. More severe effects could occur if an animal gets 
close enough to the source to receive a comparatively higher level, is 
exposed continuously to one source for a longer time, or is exposed 
intermittently to different sources throughout a day. Such effects 
might result in an animal having a more severe flight response and 
leaving a larger area for a day or more or potentially losing feeding 
opportunities for a day. However, such severe behavioral effects are 
expected to occur infrequently.
    Many species perform vital functions, such as feeding, resting, 
traveling, and socializing on a diel cycle (24-hour cycle). Behavioral 
reactions to noise exposure, when taking place in a biologically 
important context, such as disruption of critical life functions, 
displacement, or avoidance of important habitat, are more likely to be 
significant if they last more than one day or recur on subsequent days 
(Southall et al., 2007) due to diel and lunar patterns in diving and 
foraging behaviors observed in many cetaceans (Baird et al., 2008, 
Barlow et al., 2020, Henderson et al., 2016, Schorr et al., 2014). It 
is important to note the water depth in the CVOW-C project area is 
generally shallow (less than 40 m) and deep diving species, such as 
sperm whales, are not expected to be engaging in deep foraging dives 
when exposed to noise above NMFS harassment thresholds during the 
specified activities. Therefore, we do not anticipate impacts to deep 
foraging behavior to be impacted by the specified activities.
    It is also important to identify that the estimated number of takes 
does not necessarily equate to the number of individual animals 
Dominion Energy expects to harass (which is likely lower for some 
species) but rather, to the instances of take (i.e., exposures above 
the Level B harassment thresholds) that are anticipated to occur. Some 
individuals of a species or stock may experience one exposure as they 
move through an area while other individuals of a species may 
experience recurring instances of take over multiple days throughout 
the year while some, which would mean (in the latter case) that the 
number of individuals taken is smaller than the total estimated 
instances of takes. In short, for species that are more likely to be 
migrating through the area and/or for which only a comparatively 
smaller number of takes are predicted (e.g., some of the mysticetes), 
it is more likely that each take represents a

[[Page 28755]]

different individual whereas for non-migrating species with larger 
amounts of estimated take, we expect that the total anticipated takes 
represent exposures of a smaller number of individuals of which some 
would be exposed multiple times.
    For the CVOW-C project, impact pile driving is likely to result in 
a higher magnitude and severity of behavioral disturbance than 
vibratory pile driving, HRG surveys, or other activities. Impact pile 
driving has higher source levels than vibratory pile driving and HRG 
sources. HRG survey equipment also produces much higher frequencies 
than pile driving, resulting in minimal sound propagation. While impact 
pile driving is anticipated to be most impactful for these reasons, 
impacts are minimized through implementation of mitigation measures, 
including soft-start, use of a sound attenuation system, and the 
implementation of clearance zones that would facilitate a delay of pile 
driving if marine mammals were observed approaching or within areas 
that could be ensonified above sound levels that could result in Level 
B harassment. Given sufficient notice through the use of soft-start, 
marine mammals are expected to move away from a sound source prior to 
becoming exposed to very loud noise levels. The requirement that pile 
driving can only commence when the full extent of all clearance zones 
are fully visible to visual PSOs would ensure a higher marine mammal 
detection, enabling a high rate of success in implementation of 
clearance zones. Furthermore, Dominion Energy would be required to 
utilize PAM to augment visual observations prior to and during all 
clearance periods, during impact pile driving, and after pile driving 
has ended during the post-piling period. PAM has been shown to be 
particularly effective when used in conjunction with visual 
observations, increasing the overall capability to detect marine 
mammals (Van Parijs et al., 2021).
    Occasional, milder behavioral reactions are unlikely to cause long-
term consequences for individual animals or populations, and even if 
some smaller subset of the takes are in the form of a longer (several 
hours or a day) and more severe response, if they are not expected to 
be repeated over sequential days, impacts to individual fitness are not 
anticipated. Nearly all studies and experts agree that infrequent 
exposures of a single day or less are unlikely to impact an 
individual's overall energy budget (Farmer et al., 2018; Harris et al., 
2017; King et al., 2015; NAS 2017; New et al., 2014; Southall et al., 
2007; Villegas-Amtmann et al., 2015).

Temporary Threshold Shift

    TTS is one form of Level B harassment that marine mammals may incur 
through exposure to Dominion Energy's activities and, as described 
earlier, the proposed takes by Level B harassment may represent takes 
in the form of behavioral disturbance, TTS, or both. As discussed in 
the Potential Effects to Marine Mammals and their Habitat section, in 
general, TTS can last from a few minutes to days, be of varying degree, 
and occur across different frequency bandwidths, all of which determine 
the severity of the impacts on the affected individual, which can range 
from minor to more severe. Impact and vibratory pile driving generate 
sounds in the lower frequency ranges (with most of the energy below 1-2 
kHz, but with a small amount energy ranging up to 20 kHz); therefore, 
in general and all else being equal, we would anticipate the potential 
for TTS is higher in low-frequency cetaceans (i.e., mysticetes) than 
other marine mammal hearing groups and would be more likely to occur in 
frequency bands in which they communicate. However, though the 
frequency range of TTS that marine mammals might sustain would overlap 
with some of the frequency ranges of their vocalizations, the frequency 
range of TTS from Dominion Energy's pile driving activities would not 
typically span the entire frequency range of one vocalization type, 
much less span all types of vocalizations or other critical auditory 
cues for any given species. Furthermore, the mitigation measures 
proposed by Dominion Energy and proposed by NMFS further reduce the 
potential for TTS in mysticetes.
    Generally, both the degree of TTS and the duration of TTS would be 
greater if the marine mammal is exposed to a higher level of energy 
(which would occur when the peak dB level is higher or the duration is 
longer). The threshold for the onset of TTS was discussed previously 
(refer back to the Level B Harassment section in Marine Mammal Acoustic 
Thresholds). However, source level alone is not a predictor of TTS. An 
animal would have to approach closer to the source or remain in the 
vicinity of the sound source appreciably longer to increase the 
received SEL, which would be difficult considering the proposed 
mitigation and the nominal speed of the receiving animal relative to 
the stationary sources such as impact pile driving. The recovery time 
of TTS is also of importance when considering the potential impacts 
from TTS. In TTS laboratory studies (as discussed in the Potential 
Effects to Marine Mammals and their Habitat section), some using 
exposures of almost an hour in duration or up to 217 SEL, almost all 
individuals recovered within 1 day (or less, often in minutes) and we 
note that while the pile driving activities last for hours a day, it is 
unlikely that most marine mammals would stay in the close vicinity of 
the source long enough to incur more severe TTS. Overall, given the 
small number of times that any individual might incur TTS, the low 
degree of TTS and the short anticipated duration, and the unlikely 
scenario that any TTS overlapped the entirety of a critical hearing 
range, it is unlikely that TTS of the nature expected to result from 
Dominion Energy's activities would result in behavioral changes or 
other impacts that would impact any individual's (of any hearing 
sensitivity) reproduction or survival.

Permanent Threshold Shift

    Dominion Energy has requested and NMFS proposed to authorize a very 
small amount of take by PTS to some marine mammal individuals. The 
maximum amount of Level A harassment proposed to be authorized is 
relatively low for all marine mammal stocks and species: humpback 
whales (4 takes), fin whales (4 takes), sei whales (1 take), minke 
whale (8 takes), harbor porpoises (1 take), gray seals (1 take), and 
harbor seals (1 take). The only activities we anticipate PTS may result 
from are exposure to impact pile driving foundation piles, an activity 
that produces sound that is both impulsive and primarily concentrated 
in the lower frequency ranges (below 1 kHz) (David, 2006; Krumpel et 
al., 2021). Take by Level A harassment incidental to any other activity 
is not anticipated due to either the nature of the source (e.g., HRG 
survey equipment) or the very small distances to Level A harassment 
isopleths (e.g., the distance to PTS thresholds for vibratory driving 
large foundation piles is less than 158 m for all species).
    There are no PTS data on cetaceans and only one instance of PTS 
being induced in an older harbor seals (Reichmuth et al., 2019); 
however, available TTS data (of mid-frequency hearing specialists 
exposed to mid- or high-frequency sounds (Southall et al., 2007; NMFS 
2018; Southall et al., 2019)) suggest that most threshold shifts occur 
in the frequency range of the source up to one octave higher than the 
source. We would anticipate a similar result for PTS. Further, no more 
than a small degree of PTS is expected to be associated with any of the 
incurred Level A harassment given it is unlikely that animals would 
stay in the close

[[Page 28756]]

vicinity of a source for a duration long enough to produce more than a 
small degree of PTS.
    PTS would consist of minor degradation of hearing capabilities 
occurring predominantly at frequencies one-half to one octave above the 
frequency of the energy produced by pile driving (i.e., the low-
frequency region below 2 kHz) (Cody and Johnstone, 1981; McFadden, 
1986; Finneran, 2015), not severe hearing impairment. If hearing 
impairment occurs from impact pile driving, it is most likely that the 
affected animal would lose a few decibels in its hearing sensitivity, 
which in most cases is not likely to meaningfully affect its ability to 
forage and communicate with conspecifics. However, given sufficient 
notice through use of soft-start prior to implementation of full hammer 
energy during impact pile driving, marine mammals are expected to move 
away from a sound source prior to it resulting in severe PTS.

Auditory Masking or Communication Impairment

    The ultimate potential impacts of masking on an individual are 
similar to those discussed for TTS (e.g., decreased ability to 
communicate, forage effectively, or detect predators), but an important 
difference is that masking only occurs during the time the animal is 
exposed to the signal, versus TTS, which continues beyond the duration 
of the signal. Also, though, masking can result from the sum of 
exposure to multiple signals, none of which might individually cause 
TTS. Fundamentally, masking is referred to as a chronic effect because 
one of the key potential harmful components of masking is its 
duration--the fact that an animal would have reduced ability to hear or 
interpret critical cues becomes much more likely to cause a problem the 
longer it is occurring. Also inherent in the concept of masking is the 
fact that the potential for the effect is only present during the times 
that the animal and the source are in close enough proximity for the 
effect to occur (and further, this time period would need to coincide 
with a time that the animal was utilizing sounds at the masked 
frequency). As our analysis has indicated, for this project we expect 
that pile driving foundations have the greatest potential to mask 
marine mammal signals, and this pile driving may occur for several, 
albeit intermittent, hours per day, given the need to switch between 
vibratory and impact hammers. Masking is fundamentally more of a 
concern at lower frequencies (which are pile driving dominant 
frequencies) because low frequency signals propagate significantly 
further than higher frequencies and because they are more likely to 
overlap both the narrower low frequency calls of mysticetes, as well as 
many non-communication cues related to fish and invertebrate prey, and 
geologic sounds that inform navigation. However, the area in which 
masking would occur for all marine mammal species and stocks (e.g., 
predominantly in the vicinity of the foundation pile being driven) is 
small relative to the extent of habitat used by each species and stock. 
In summary, the nature of Dominion Energy's activities, paired with 
habitat use patterns by marine mammals, does not support the likelihood 
that the level of masking that could occur would have the potential to 
affect reproductive success or survival.

Impacts on Habitat and Prey

    As previously discussed in the Potential Effects of Specified 
Activities to Marine Mammals and their Habitat section, construction 
activities may result in fish and invertebrate mortality or injury very 
close to the source, and all activities (including HRG surveys) may 
cause some fish to leave the area of disturbance. It is anticipated 
that any mortality or injury would be limited to a very small subset of 
available prey and the implementation of mitigation measures, such as 
the use of a noise attenuation system during impact pile driving of 
foundations, would further limit the degree of impact. Behavioral 
changes in prey in response to construction activities could 
temporarily impact marine mammals' foraging opportunities in a limited 
portion of the foraging range but because of the relatively small area 
of the habitat that may be affected at any given time (e.g., around a 
pile being driven), the impacts to marine mammal habitat are not 
expected to cause significant or long-term negative consequences.
    Cable presence and operation are not anticipated to impact marine 
mammal habitat as these would be buried, and any electromagnetic fields 
emanating from the cables are not anticipated to result in consequences 
that would impact marine mammals prey to the extent they would be 
unavailable for consumption.
    The presence and operation of wind turbines within the Lease Area 
could have longer-term impacts on marine mammal habitat, as the project 
would result in the persistence of the structures within marine mammal 
habitat for more than 30 years. The presence and operation of an 
extensive number of structures, such as wind turbines, are, in general, 
likely to result in local and broader oceanographic effects in the 
marine environment and may disrupt dense aggregations and distribution 
of marine mammal zooplankton prey through altering the strength of 
tidal currents and associated fronts, changes in stratification, 
primary production, the degree of mixing, and stratification in the 
water column (Chen et al., 2021, Johnson et al., 2021, Christiansen et 
al., 2022, Dorrell et al., 2022). However, the scale of impacts is 
difficult to predict and may vary from hundreds of meters for local 
individual turbine impacts (Schultze et al., 2020) to large-scale 
dipoles of surface elevation changes stretching hundreds of kilometers 
(Christiansen et al., 2022).
    As discussed in the Potential Effects to Marine Mammals and Their 
Habitat section, the CVOW-C proposed project would consist of no more 
than 176 WTGs (all of which are scheduled to be operational by the end 
of 2027) in Federal and state waters off of Virginia, an area dominated 
by physical oceanographic patterns of strong seasonal stratification 
(summer) and turbulence-driven mixing (winter), with a maximum of 183 
piling events for all WTGs. While there are likely to be local 
oceanographic impacts from the presence and operation of the CVOW-C 
project area, meaningful oceanographic impacts relative to 
stratification and mixing that would significantly affect marine mammal 
habitat and prey over large areas in key habitats are not anticipated 
from the CVOW-C project. Although this area supports aggregations of 
zooplankton (baleen whale prey) that could be impacted if long-term 
oceanographic changes occurred, prey densities are typically 
significantly less in the CVOW-C project area than in known baleen 
whale foraging habitats to the northern areas off the New England coast 
(e.g., south of Nantucket and Martha's Vineyard, Great South Channel). 
For these reasons, if oceanographic features are affected by wind farm 
operation during the course of the proposed rule (approximately end of 
Year 2 through Year 5), the impact on marine mammal habitat and their 
prey is likely to be comparatively minor.

Mitigation To Reduce Impacts on All Species

    This proposed rulemaking includes a variety of mitigation measures 
designed to minimize impacts on all marine mammals, with a focus on 
North Atlantic right whales (the latter is described in more detail 
below). For the dual approach of vibratory and impact pile driving of 
foundation piles, nine

[[Page 28757]]

overarching mitigation measures are proposed, which are intended to 
reduce both the number and intensity of marine mammal takes: (1) 
seasonal/time of day work restrictions; (2) use of multiple PSOs to 
visually observe for marine mammals (with any detection within 
designated zones triggering delay or shutdown); (3) use of PAM to 
acoustically detect marine mammals, with a focus on detecting baleen 
whales (with any detection within designated zones triggering delay or 
shutdown); (4) implementation of clearance zones; (5) implementation of 
shutdown zones; (6) use of soft-start; (7) use of noise abatement 
technology; (8) maintaining situational awareness of marine mammal 
presence through various communication and network monitoring 
requirements; and (9) use of sound field verification. Several of these 
proposed mitigation measures are also applicable to other proposed 
activities (e.g., use of PSOs and clearance and shutdown zones) while 
others are not considered viable for some activities (e.g., PAM during 
non-foundation installation activities, use and seasonal/time of day 
work restrictions during HRG surveys; and use of soft-start during 
vibratory installation of cofferdams). These are discussed in more 
detail above in the relevant sections found in Proposed Mitigation 
Measures.
    When foundation installation does occur, Dominion Energy is 
committed to reducing the noise levels generated by impact pile driving 
to the lowest levels practicable and ensuring that they do not exceed a 
noise footprint above that which was modeled assuming a 10-dB 
attenuation. Use of a soft-start would allow animals to move away from 
(i.e., avoid) the sound source prior to applying higher hammer energy 
levels needed to install the pile (Dominion Energy would not use a 
hammer energy greater than necessary to install piles). Clearance zone 
and shutdown zone implementation, required when marine mammals are 
within given distances associated with certain impact thresholds, would 
reduce the magnitude and severity of marine mammal take.
    Dominion Energy proposed, and NMFS proposed to require, use a noise 
attenuation device (likely a double big bubble curtain, another 
technology, or combination of technologies, such as a hydro-sound 
damper) during all foundation pile driving to ensure sound generated 
from the project does not exceed that modeled (assuming a 10-dB 
reduction) distances to harassment isopleths and to minimize noise 
levels to the lowest level practicable. Double big bubble curtains are 
successfully and widely applied across European wind development 
efforts, and are known to reduce noise levels more than a single big 
bubble curtain alone (e.g., see Bellman et al., 2020).

Mysticetes

    Five mysticete species (comprising five stocks) of cetaceans (North 
Atlantic right whale, humpback whale, fin whale, sei whale, and minke 
whale) are proposed to be taken by harassment. These species, to 
varying extents, utilize coastal Virginia waters, including the project 
area, primarily for the purposes of migration. Key foraging grounds for 
most of these species are located hundreds of kilometers north of the 
project area off of southern New England, and will not be impacted by 
Dominion Energy's activities.
    Behavioral data on mysticete reactions to pile driving noise is 
scant. Kraus et al. (2019) predicted that the three main impacts of 
offshore wind farms on marine mammals would consist of displacement, 
behavioral disruptions, and stress. Broadly, we can look to studies 
that have focused on other noise sources such as seismic surveys and 
military training exercises, which suggest that exposure to loud 
signals can result in avoidance of the sound source (or displacement if 
the activity continues for a longer duration in a place where 
individuals would otherwise have been staying, which is less likely for 
mysticetes in this area), disruption of foraging activities (if they 
are occurring in the area), local masking around the source, associated 
stress responses, and impacts to prey as well as TTS or PTS in some 
cases.
    Mysticetes encountered in the CVOW-C project area are primarily 
expected to be migrating through the project area; the extent to which 
an animal engages in these behaviors in the area is species-specific 
and varies seasonally. Given that extensive feeding BIAs for the North 
Atlantic right whale, humpback whale, fin whale, sei whale, and minke 
whale are identified in area hundreds of kilometers north of the 
project area (LaBrecque et al., 2015; Van Parijs et al., 2015), many 
mysticetes are expected to predominantly be migrating through the 
project area towards or from these feeding habitats.
    While we have acknowledged above that mortality, hearing 
impairment, or displacement of mysticete prey species may result 
locally from impact pile driving, the project area during which time 
impact pile driving of foundations may occur is not a known key 
foraging area. Impact pile driving foundations would not occur in 
winter when whales (e.g., humpback whales) are more likely to be 
foraging within the project area. Primary mysticete foraging grounds 
(i.e., much more suitable foraging habitat) are found much further 
north of the CVOW-C project area. Whales temporarily displaced from the 
proposed project area would be expected to have sufficient remaining 
habitat available to them and would not be prevented from migrating 
through other areas outside the CVOW-C project area. In addition, any 
displacement of whales or interruption of any potential foraging bouts 
that may occur sporadically during transit would be expected to be 
temporary in nature. Hence, any impacts on mysticetes foraging would be 
expected to be negligible.
    The potential for repeated exposures is dependent upon the 
residency time of whales, with migratory animals unlikely to be exposed 
on repeated occasions and animals remaining in the area to be more 
likely exposed repeatedly. As is the case here, where relatively low 
amounts of species-specific proposed Level B harassment are predicted 
(Tables 27, 28, and 29) and movement patterns suggest that individuals 
would not necessarily linger in a particular area for multiple days, 
each estimated take likely represents an exposure of a different 
individual. The behavioral impacts to any given individual would, 
therefore, be expected to occur within a single day within a year--an 
amount that would not be expected to impact reproduction or survival. 
Alternatively, species with longer residence time in the project area 
may be subject to repeated exposures. In general, for this project, the 
duration of exposures would not be continuous throughout any given day 
and pile driving would not occur on all consecutive days within a given 
year due to weather delays, other planned activities in the 
construction schedule, and any number of logistical constraints that 
Dominion Energy has already identified. Given mysticete habitat use of 
waters off Virginia is predominately migratory in nature (reducing the 
likelihood of repeated exposures), we do not anticipate whales to 
experience repeated exposures, if it does occur, to the degree any 
meaningful consequence to reproduction or survival would occur. 
Species-specific analysis regarding potential for repeated exposures 
and impacts is provided below. Overall, we do not expect impacts to 
whales within the CVOW-C project area to affect the fitness of any 
large whales.
    NMFS is proposing to authorize Level A harassment (in the form of 
PTS) of fin, minke, humpback, and sei whales incidental to installation 
of the WTG and OSS foundations. As described

[[Page 28758]]

previously, PTS for mysticetes from impact pile driving may overlap 
frequencies used for communication, navigation, or detecting prey. 
However, given the nature and duration of the activity, the mitigation 
measures, and likely avoidance behavior, any PTS is expected to be of a 
small degree, would be limited to frequencies where pile driving noise 
is concentrated (i.e., only a small subset of their expected hearing 
range) and would not be expected to impact reproductive success or 
survival.

North Atlantic Right Whales

    North Atlantic right whales are listed as endangered under the ESA 
and as described in the Effects to Marine Mammals and Their Habitat 
section, are threatened by a low population abundance, higher than 
average mortality rates, and lower than average reproductive rates. 
Recent studies have reported individuals showing high stress levels 
(e.g., Corkeron et al., 2017) and poor health, which has further 
implications on reproductive success and calf survival (Christiansen et 
al., 2020; Stewart et al., 2021; Stewart et al., 2022). Given this, the 
status of the North Atlantic right whale population is of heightened 
concern and therefore, merits additional analysis and consideration.
    North Atlantic right whales are presently experiencing an ongoing 
UME (beginning in June 2017). Preliminary findings support human 
interactions, specifically vessel strikes and entanglements, as the 
cause of death for the majority of North Atlantic right whales. Given 
the current status of the North Atlantic right whale, the loss of even 
one individual could significantly impact the population. No mortality, 
serious injury, or injury of North Atlantic right whales as a result of 
the project is expected or proposed to be authorized. Any disturbance 
to North Atlantic right whales due to Dominion Energy's activities is 
expected to result in temporary avoidance of the immediate area of 
construction. As no injury, serious injury, or mortality is expected or 
authorized, and Level B harassment of North Atlantic right whales will 
be reduced to the level of least practicable adverse impact through use 
of mitigation measures, the authorized number of takes of North 
Atlantic right whales would not exacerbate or compound the effects of 
the ongoing UME in any way.
    NMFS proposes to authorize a maximum of 7 takes of North Atlantic 
right whales by Level B harassment only in any given year (primarily 
due to activities occurring in Years 1 and 2) with no more than 17 
takes incidental to all construction activities over the 5-year period 
of effectiveness of this proposed rule.
    As described above, the CVOW-C project area represents part of a 
migratory corridor that North Atlantic right whales use for transit 
between northern feeding grounds in New England and southern calving 
grounds off Georgia and Florida. Northward migration occurs mainly 
during the months of March and April while southern transit typically 
takes place during the months of November and December (LaBrecque et 
al., 2015; Van Parijs et al., 2015). Overall, the CVOW-C project area 
contains habitat less frequently utilized by North Atlantic right 
whales than the foraging and calving grounds. Salisbury et al. (2015) 
detected North Atlantic right whales year-round off the coast of 
Virginia, yet they were only detected on 10 percent of the days from 
May through October. The greatest detections occurred from October 
through December and February through March, outside of the months of 
Dominion Energy's planned foundation installation. Therefore, we 
anticipate that any individual whales would typically be migrating 
through the project area and would not be lingering for extended 
periods of time and, further, fewer would be present in the months when 
foundation installation would be occurring. Other proposed activities 
by Dominion Energy that involve either much smaller harassment zones 
(i.e., HRG surveys) or are limited in amount and nearshore in location 
(i.e., cable landfall construction) may occur during periods when North 
Atlantic right whales are more likely to be migrating through. However, 
North Atlantic right whales would be less likely to occur within the 
project area during the time when the most impactful project activities 
would take place.
    As any North Atlantic right whales within the project area would 
likely be engaged in migratory behavior (LaBrecque et al., 2015), it is 
likely that the estimated instances of take would occur to separate 
individual whales; however, some may be repeat takes of the same animal 
across multiple days for some short period of time. The only activity 
occurring from December through May that may impact North Atlantic 
right whale would be HRG surveys no take from cable landfall 
construction is anticipated or proposed to be authorized). Across all 
years, while it is possible an animal could have been exposed during a 
previous year, the low amount of take proposed to be authorized during 
the 5-year period of the proposed rule makes this scenario possible but 
unlikely. However, if an individual were to be exposed during a 
subsequent year, the impact of that exposure is likely independent of 
the previous exposure given the duration between exposures.
    As described in the general Mysticete section above, installation 
of foundation piles by both impact and vibratory pile driving has the 
potential to result in the highest amount of annual take of North 
Atlantic right whales (7 Level B harassment takes) and is of greatest 
concern given the louder source levels present during impact pile 
driving. However, foundation installation would likely be limited to 
two years, during times when North Atlantic right whales are not 
present in high numbers and are likely to be primarily migrating to 
more northern foraging grounds. Furthermore, the potential types, 
severity, and magnitude of impacts are also anticipated to mirror that 
described in the general Mysticete section above, including avoidance 
(the most likely outcome), changes in foraging or vocalization 
behavior, masking, a small amount of TTS, and temporary physiological 
impacts (e.g., change in respiration, change in heart rate). 
Importantly, the effects of the activities proposed by Dominion Energy 
are expected to be sufficiently low-level and localized to specific 
areas as to not meaningfully impact important behaviors such as 
migratory behavior of North Atlantic right whales.
    As described above, no more than 7 takes of North Atlantic right 
whales would occur in any given year (likely in Year 1 or Year 2 if all 
foundations are installed according to the construction schedule 
provided by Dominion Energy) with no more than 17 takes occurring 
across the 5 years the proposed rule would be effective. If exposure 
results in temporary behavioral reactions, such as slight displacement 
(but not abandonment), it is unlikely to result in energetic 
consequences that could affect reproduction or survival of any 
individuals. Overall, NMFS expects that any harassment of North 
Atlantic right whales incidental to the specified activities would not 
result in meaningful changes to their migration patterns or disruption 
of foraging behavior as only temporary avoidance of an area during 
construction is expected to occur. As described previously, right 
whales migrating through these areas are not expected to remain in this 
habitat for extensive durations. Because of this, NMFS expects that any 
temporarily displaced animals would be able to return to or continue to 
travel through these areas once Dominion

[[Page 28759]]

Energy's proposed construction activities have ceased.
    Although acoustic masking may occur, based on the acoustic 
characteristics of noise associated with pile driving (e.g., frequency 
spectra, short duration of exposure) and construction surveys (e.g., 
intermittent signals), NMFS expects masking effects to be minimal 
(e.g., impact or vibratory pile driving) to none (e.g., HRG surveys). 
In addition, masking would likely only occur during the period of time 
that a North Atlantic right whale is in the relatively close vicinity 
of pile driving, which is expected to be infrequent and brief given 
time of year restrictions, anticipated mitigation effectiveness, and 
likely avoidance behaviors. TTS is another potential form of Level B 
harassment that could result in brief periods of slightly reduced 
hearing sensitivity affecting behavioral patterns by making it more 
difficult to hear or interpret acoustic cues within the frequency range 
(and slightly above) of sound produced during impact pile driving. 
However, any TTS would likely be of low amount and limited to 
frequencies where most construction noise is centered (below 2 kHz). 
NMFS expects that right whale hearing sensitivity would return to pre-
exposure levels shortly after migrating through the area or moving away 
from the sound source.
    As described in the Potential Effects to Marine Mammals and Their 
Habitat section, the distance of the receiver to the source influences 
the severity of response with greater distances typically eliciting 
less severe responses. Additionally, NMFS recognizes North Atlantic 
right whales migrating could be pregnant females (in the fall) and cows 
with older calves (in spring) and that these animals may slightly alter 
their migration course in response to any foundation pile driving. 
However, as described in the Potential Effects to Marine Mammals and 
Their Habitat section, we anticipate that course diversion would be of 
small magnitude. Hence, while some avoidance of the pile driving 
activities may occur, we anticipate any avoidance behavior of migratory 
right whales would be similar to that of gray whales (Tyack et al., 
1983), on the order of hundreds of meters up to 1 to 2 km. This slight 
diversion from an otherwise uninterrupted path is neither anticipated 
to push North Atlantic right whales out of their migratory habitat nor 
expected to result in meaningful energetic costs that would impact 
annual rates of recruitment of survival. NMFS expects that North 
Atlantic right whales would be able to avoid areas during periods of 
active noise production while not being forced out of this portion of 
their habitat.
    Dominion Energy has proposed, and NMFS is proposing to require, a 
suite of enhanced mitigation measures designed to reduce impacts to 
North Atlantic right whales to the maximum extent practicable. These 
mitigation measures are fully described in the Proposed Mitigation 
section above and are designed to minimize the amount and severity of 
Level B harassment (TTS and behavioral disruptions) by minimizing the 
potential for exposure and, if exposures do occur, the noise levels and 
duration associated with those exposures. Implementation of these 
measures further ensure that takes by Level B harassment proposed to be 
authorized would not be expected to affect reproductive success or 
survivorship of species during migratory transit.
    As described in the Description of Marine Mammals in the Area of 
Specified Activities section, the proposed CVOW-C project would be 
constructed within the North Atlantic right whale migratory corridor 
BIA, which represent areas and months within which a substantial 
portion of a species or population is known to migrate. Off the coast 
of Virginia, this BIA extends from the coast to beyond the shelf break. 
The CVOW-C Lease Area is relatively small compared with the migratory 
BIA area (approximately 456.5 km\2\ versus the size of the full North 
Atlantic right whale migratory BIA, 269,448 km\2\). Because of this and 
for reasons described above, overall North Atlantic right whale 
migration is not expected to be impacted by the proposed activities. 
There are no known North Atlantic right whale mating or calving areas 
within the project area. Impact pile driving, which is responsible for 
the majority of North Atlantic right whale impacts from the CVOW-C 
project, would be limited to a maximum of approximately 9 intermittent 
hours per day (inclusive of a maximum daily built-out of two 
intermittent 4-hour pile driving events and the 1.2 hour transition 
time between vibratory equipment to impact); therefore, if migratory 
activities are disrupted due to foundation pile driving, any disruption 
would be brief as North Atlantic right whales would likely resume 
migrating after pile driving ceases or when animals move away from the 
sound source to another nearby location. The Chesapeake Bay SMA, a 
management tool designed to reduce vessel strikes, also temporally and 
spatially overlaps a small portion of the project area for a portion of 
the year. Given the vessel speed regulations and other enhanced 
measures within this proposed rule, vessel strike of a North Atlantic 
right whale is not anticipated and no take, by mortality, serious 
injury, or non-auditory injury (potential outcomes of a vessel strike) 
is proposed for authorization.
    The primary prey species for the North Atlantic right whale are 
mobile (e.g., calanoid copepods can initiate rapid and directed escape 
responses) and are broadly distributed much further north from the 
CVOW-C project area (noting again that North Atlantic right whale prey 
is not particularly concentrated in the CVOW-C project area relative to 
nearby habitats). Therefore, any impacts to prey that may occur are 
also unlikely to impact marine mammals.
    The most significant measure to minimize impacts to individual 
North Atlantic right whales during monopile installations is the 
seasonal moratorium on impact pile driving of monopiles from November 
1st through April 30th when North Atlantic right whale abundance in the 
project area is expected to be highest for the proposed construction 
period. NMFS also expects this measure to greatly reduce the potential 
for mother-calf pairs to be exposed to foundation pile driving noise 
above the Level B harassment threshold during their annual spring 
migration through the CVOW-C project area from southern calving grounds 
to the foraging grounds in southern New England and north. Further, 
NMFS expects that exposures to North Atlantic right whales would be 
reduced due to the additional proposed mitigation measures that would 
ensure that any exposures above the Level B harassment threshold would 
result in only short-term effects to individuals exposed. Impact pile 
driving may only begin in the absence of North Atlantic right whales 
(based on visual and passive acoustic monitoring). If impact pile 
driving has commenced, NMFS anticipates North Atlantic right whales 
would avoid the area, utilizing nearby waters to carry on pre-exposure 
behaviors. However, NMFS proposes to require that impact pile driving 
must be shut down if a North Atlantic right whale is sighted at any 
distance unless a shutdown is not feasible due to risk of injury or 
loss of life, pile refusal, or pile instability. Shutdown may occur 
anywhere if right whales are seen within or beyond the Level B 
harassment zone, further minimizing the duration and intensity of 
exposure. NMFS anticipates that if North Atlantic right whales go 
undetected and they are exposed to impact pile driving noise, it is 
unlikely a North Atlantic right whale

[[Page 28760]]

would approach the impact pile driving locations to the degree that 
they would purposely expose themselves to very high noise levels. These 
measures are designed to avoid PTS and also reduce the severity of 
Level B harassment, including the potential for TTS. While some TTS 
could occur, given the proposed mitigation measures (e.g., delay pile 
driving upon a sighting or acoustic detection and shutting down upon a 
sighting or acoustic detection), the potential for TTS to occur is low.
    The proposed clearance and shutdown measures are most effective 
when detection efficiency is maximized, as the measures are triggered 
by a sighting or acoustic detection. To maximize detection efficiency, 
Dominion Energy proposed, and NMFS is proposing to require the 
combination of PAM and visual observers (as well as communication 
protocols with other Dominion Energy vessels, and other heightened 
awareness efforts such as daily monitoring of North Atlantic right 
whale sighting databases) such that as a North Atlantic right whale 
approaches the source (and thereby could be exposed to higher noise 
energy levels), PSO detection efficacy would increase, the whale would 
be detected, and a delay to commencing pile driving or shutdown (if 
feasible) would occur. In addition, the implementation of a soft start 
would provide an opportunity for whales to move away from the source if 
they are undetected, reducing received levels. Further, Dominion Energy 
has committed to not installing two WTG or OSS foundations 
simultaneously. North Atlantic right whales would, therefore, not be 
exposed to concurrent impact pile driving on any given day and the area 
ensonified at any given time would be limited. We further note that 
Dominion Energy has not requested to install foundation piles at night, 
which is likely to further improve the ability of observers to spot and 
identify any approach or transiting North Atlantic right whales.
    Dominion Energy anticipates a need to undertake a dual vibratory 
and impact pile driving approach for foundation piles to avoid risks 
associated with pile run due to softer sedimentation in the CVOW-C 
project area. While Dominion Energy expects that up to 70 percent of 
their piles may necessitate this joint approach (approximately 123 
foundation piles), realistically not all piles would be at risk of pile 
run and would be installed by impact pile driving. However, as a 
conservative approach given uncertainty with the seabed conditions for 
the location of each pile, Dominion Energy assumed all foundation piles 
would undertake this approach. Furthermore, Dominion Energy has already 
stated that no concurrent installation of foundation piles is planned 
to occur, no concurrent vibratory and impact driving is expected to 
occur either as a 1.2 hour gap between the end vibratory driving to the 
start of impact pile driving (to allow for the moving and set-up of 
equipment) would treat each installation approach as a separate event 
and would not overlap.
    Finally, for HRG surveys, the maximum distance to the Level B 
harassment isopleth is 100 m. The estimated take, by Level B harassment 
only, associated with HRG surveys is to account for any North Atlantic 
right whale sightings PSOs may miss when HRG acoustic sources are 
active. However, because of the short maximum distance to the Level B 
harassment isopleth (100 m via the GeoMarine Dual 400 Sparker 800 J), 
the requirement that vessels maintain a distance of 500 m from any 
North Atlantic right whales, the fact whales are unlikely to remain in 
close proximity to an HRG survey vessel for any length of time, and 
that the acoustic source would be shutdown if a North Atlantic right 
whale is observed within 500 m of the source, any exposure to noise 
levels above the harassment threshold (if any) would be very brief and 
at comparatively low received levels. To further minimize exposures, 
ramp-up of boomers, sparkers, and CHIRPs must be delayed during the 
clearance period if PSOs detect a North Atlantic right whale (or any 
other ESA-listed species) within 500 m of the acoustic source. 
Potential impacts associated with Level B harassment would include low-
level, temporary behavioral modifications, most likely in the form of 
brief avoidance behavior that would return to baseline conditions once 
the vessel leaves the area. Given the high level of precautions taken 
to minimize both the amount and intensity of Level B harassment on 
North Atlantic right whales, it is unlikely that the anticipated low-
level exposures would lead to reduced reproductive success or survival 
of any individuals.
    North Atlantic right whales are listed as endangered under the ESA 
with a declining population primarily due to vessel strike and 
entanglement. Again, NMFS is proposing to authorize no more than 17 
instances of take, by Level B harassment only, within the a given year 
with no more than 7 instances of take could occur over the 5-year 
effective period of the proposed rule, with the likely scenario that 
each instance of exposure occurs to a different individual (a small 
portion of the stock), and any individual North Atlantic right whale is 
likely to be disturbed at a low level. The low magnitude and severity 
of harassment are not expected to result in impacts on the reproduction 
or survival of any individuals, let alone have impacts on annual rates 
of recruitment or survival of this stock. No mortality, serious injury, 
or Level A harassment is anticipated or proposed to be authorized. For 
these reasons, we have preliminarily determined, in consideration of 
all of the effects of Dominion Energy's activities combined, that the 
proposed authorized take would have a negligible impact on the Western 
North Atlantic stock of North Atlantic right whales.

Humpback Whales

    Humpback whales potentially impacted by Dominion Energy's 
activities do not belong to a DPS that is listed as threatened or 
endangered under the ESA. However, humpback whales along the Atlantic 
Coast have been experiencing an active UME as elevated humpback whale 
mortalities have occurred along the Atlantic coast from Maine through 
Florida since January 2016. Of the cases examined, approximately half 
had evidence of human interaction (ship strike or entanglement). The 
UME does not yet provide cause for concern regarding population-level 
impacts, and take from ship strike and entanglement is not proposed to 
be authorized. Despite the UME, the relevant population of humpback 
whales (the West Indies breeding population, or DPS of which the Gulf 
of Maine stock is a part) remains stable at approximately 12,000 
individuals.
    Dominion Energy has requested, and NMFS has proposed to authorize 
incidental take by Level A harassment (n=8) and Level B harassment 
(n=242) over the five-year effective period of the rule, with no more 
than 4 takes by Level A harassment and 130 takes by Level B harassment 
in any year (likely year one or two, with fewer anticipated in other 
years). No mortality or serious injury is anticipated or proposed for 
authorization. Among the activities analyzed, impact pile driving has 
the potential to result in the highest amount of annual take of 
humpback whales and is of greatest concern, given the associated louder 
source levels. As mentioned earlier, humpback whales are generally 
migratory in Virginia waters, although the mid-Atlantic region may also 
serve as a supplemental winter feeding ground for juvenile and mature 
male humpback whales (Mallette et al., 2017; Barco et al., 2002; 
LaBrecque et

[[Page 28761]]

al., 2015). Although there is limited information about the specific 
migratory path, humpback whale migration may take place in the open 
ocean or on the continental shelf of the mid-Atlantic region (Barco et 
al., 2002; LaBrecque et al., 2015), thus, potentially overlapping with 
the project area during the spring or fall. Juvenile and adult male 
humpback whales may utilize Virginia waters as a feeding ground during 
the winter months (December-March) (Barco et al., 2002), however this 
habitat is anticipated to be used less frequently than the northern 
summer feeding grounds. The most impactful project activities are 
planned to occur from May through October, outside of the time when 
humpback whales are expected to be migrating through the area or using 
Virginia waters as a feeding ground. Humpback whales would therefore be 
less likely to occur during the time when the most impactful project 
activities would take place.
    The 130 maximum annual instances of estimated take by Level B 
harassment would likely consist of individuals exposed to noise levels 
above the harassment thresholds once during migration through the CVOW-
C project area and/or individuals exposed on multiple days if they are 
utilizing the area as foraging habitat. Based on the observed winter 
peaks in humpback whale seasonal distribution in the Virginia region, 
it is likely that these individuals would primarily be exposed to HRG 
survey activities given there is no time of year restriction for this 
activity. The proposed pile driving restrictions for foundation 
installation and cable landfall activities are designed around North 
Atlantic right whales; however, this seasonal restriction also affords 
protection to humpback whales utilizing the waters off of Virginia 
during the winter months.
    For all the reasons described in the Mysticete section above, we 
anticipate any potential PTS or TTS occurring in humpback whales would 
be small (limited to a few dB) and concentrated at half or one octave 
above the frequency band of pile driving noise (most sound is below 2 
kHz) which does not include the full predicted hearing range of baleen 
whales. If TTS is incurred, hearing sensitivity would likely return to 
pre-exposure levels shortly after exposure ends. Any masking or 
physiological responses would also be of low magnitude and severity for 
reasons described above.
    Altogether, the low magnitude and severity of harassment effects is 
not expected to result in impacts on the reproduction or survival of 
any individuals, let alone have impacts on annual rates of recruitment 
or survival of this stock. No mortality or serious injury is 
anticipated or proposed to be authorized. For these reasons, we have 
preliminarily determined, in consideration of all of the effects of 
Dominion Energy's activities combined, that the proposed authorized 
take would have a negligible impact on the Gulf of Maine stock of 
humpback whales.

Fin Whales

    The western North Atlantic stock of fin whales is listed as 
endangered under the ESA. The amount of incidental take of fin whales 
proposed for authorization in any year is 4 by Level A harassment and 
113 by Level B harassment. The 5-year total amount of fin whale take 
proposed for authorization is 7 by Level A harassment and 208 by Level 
B harassment with the majority of take occurring in the first two years 
of the proposed authorization. The amount of take proposed for 
authorization is low relative to the population abundance. No serious 
injury or mortality is anticipated or proposed for authorization. Any 
Level B harassment is expected to be in the form of behavioral 
disturbance, primarily resulting in avoidance of the Project Area where 
pile driving and HRG surveys are occurring, and some low-level TTS and 
masking that may limit the detection of acoustic cues for relatively 
brief periods of time. Any potential PTS or TTS would be small (limited 
to a few dB) and concentrated at half or one octave above the frequency 
band of pile driving noise (most sound is below 2 kHz) which does not 
include the full predicted hearing range of fin whales. As described 
previously, there are no known areas of biological importance in or 
adjacent to the project area, the closest fin whale BIA (located east 
of Montauk Point, New York) is hundreds of kilometers away.
    Because of the relatively low magnitude and severity of take 
proposed for authorization, the fact that no serious injury or 
mortality is anticipated, the temporary nature of the disturbance, and 
the availability of similar habitat and resources in the surrounding 
area, NMFS has preliminarily determined that the impacts of Dominion 
Energy's activities on fin whales are not expected to cause significant 
impacts on the reproduction or survival of any individuals, let alone 
have impacts on annual rates of recruitment or survival of this stock.

Sei Whales

    The Nova Scotia stock of sei whales are listed under the ESA. There 
are no known areas of specific biological importance in or around the 
project area, nor are there any UMEs for this species. The actual 
abundance of each stock is likely significantly greater than what is 
reflected in each draft and final SAR because, as noted in the SARs, 
the most recent population estimates are primarily based on surveys 
conducted in U.S. waters and the stock's range extends well beyond the 
U.S. EEZ.
    The maximum annual amount of incidental take of sei whales proposed 
for authorization in any year is 1 by Level A harassment and 3 by Level 
B harassment. The number of takes proposed to be authorized in the last 
three years of the rule is notably less and the 5-year total amount of 
sei whale take proposed for authorization is 2 by Level A harassment 
and 8 by Level B harassment. The amount of take proposed for 
authorization is low in the context of the population abundance. No 
serious injury or mortality is anticipated or proposed for 
authorization. Similar to other mysticetes, we would anticipate the 
number of takes to represent individuals taken only once or, in rare 
cases, an individual taken a very small number of times as most whales 
in the project area would be migrating. To a small degree, sei whales 
may forage in the project area, although the currently identified 
foraging habitats (BIAs) are found much further north of the area in 
which Dominion Energy's activities would occur (LaBrecque et al., 
2015). With respect to the severity of those individual takes by 
behavioral Level B harassment, we would anticipate impacts to be 
limited to low-level, temporary behavioral responses with avoidance and 
potential masking impacts in the vicinity of the turbine installation 
to be the most likely type of response. Any potential PTS or TTS would 
be small (limited to a few dB) and concentrated at half or one octave 
above the frequency band of pile driving noise (most sound is below 2 
kHz) which does not include the full predicted hearing range of sei 
whales. Any avoidance of the project area due to Dominion Energy's 
activities would be expected to be temporary.
    Overall, the take by harassment proposed for authorization is of a 
low magnitude and severity and is not expected to result in impacts on 
the reproduction or survival of any individuals, let alone have impacts 
on annual rates of recruitment or survival of this stock. No mortality 
or serious

[[Page 28762]]

injury is anticipated or proposed to be authorized. For these reasons, 
we have preliminarily determined, in consideration of all of the 
effects of Dominion Energy's activities combined, that the proposed 
authorized take would have a negligible impact on the Nova Scotia sei 
whale stock.

Minke Whales

    The Canadian East Coast stock of minke whales is not listed under 
the ESA. There are no known areas of specific biological importance in 
or around the project area off of Virginia. Beginning in January 2017, 
elevated minke whale strandings have occurred along the Atlantic coast 
from Maine through South Carolina, with highest numbers in 
Massachusetts, Maine, and New York. This event does not provide cause 
for concern regarding population level impacts, as the likely 
population abundance is greater than 21,000 whales. No mortality or 
serious injury of this stock is anticipated or proposed for 
authorization.
    The maximum annual amount of incidental take of minke whales 
proposed for authorization in any year is 8 by Level A harassment and 
56 by Level B harassment. The number of takes proposed to be authorized 
in the last three years of the rule is notably less (refer back to 
Table 27) and the 5-year total amount of minke whale take proposed for 
authorization is 15 by Level A harassment and 116 by Level B 
harassment. The amount of take proposed for authorization is low in the 
context of the population abundance. No serious injury or mortality is 
anticipated or proposed for authorization.
    We anticipate the impacts of this harassment to follow those 
described in the general Mysticete section above. In summary, Level B 
harassment would be temporary, with primary impacts being temporary 
displacement of the project area but not abandonment of any migratory 
or foraging behavior. Overall, the amount of take proposed to be 
authorized is small and the low magnitude and severity of harassment 
effects is not expected to result in impacts on the reproduction or 
survival of any individuals, let alone have impacts on annual rates of 
recruitment or survival of this stock. No mortality or serious injury 
is anticipated or proposed to be authorized. Any potential PTS or TTS 
would be small (limited to a few dB) and concentrated at half or one 
octave above the frequency band of pile driving noise (most sound is 
below 2 kHz) which does not include the full predicted hearing range of 
minke whales. For these reasons, we have preliminarily determined, in 
consideration of all of the effects of Dominion Energy's activities 
combined, that the proposed authorized take would have a negligible 
impact on the Canadian East Coast stock of minke whales.

Odontocetes

    In this section, we include information here that applies to all of 
the odontocete species and stocks addressed below, which are further 
divided into the following subsections: sperm whales, delphinids and 
pilot whales, and harbor porpoises. These sub-sections include more 
specific information, as well as conclusions for each stock 
represented.
    The majority of takes by harassment of odontocetes incidental to 
Dominion Energy's specified activities are by Level B harassment 
incidental to pile driving and HRG surveys. We anticipate that, given 
ranges of individuals (i.e., that some individuals remain within a 
smaller area for some period of time), and non-migratory nature of some 
odontocetes in general (especially as compared to mysticetes), these 
takes are more likely to represent multiple exposures of a smaller 
number of individuals than is the case for mysticetes, though some 
takes may also represent one-time exposures to an individual.
    Pile driving, particularly vibratory and impact pile driving of WTG 
and OSS foundation piles, has the potential to disturb odontocetes to 
the greatest extent, compared to HRG surveys and nearshore cable 
landfall activities (i.e., temporary cofferdams and goal posts). While 
we do expect animals to avoid the area during pile driving, their 
habitat range is relatively extensive compared to the area ensonified 
during pile driving.
    As described earlier, Level B harassment may manifest as changes to 
behavior (e.g., avoidance, changes in vocalizations (from masking) or 
foraging), physiological responses, or TTS. Odontocetes are highly 
mobile species and, similar to mysticetes, NMFS expects any avoidance 
behavior to be limited to the area near the pile being driven. While 
masking could occur during pile driving, it would only occur in the 
vicinity of and during the duration of the pile driving, and would not 
generally occur in a frequency range that overlaps most odontocete 
communication or echolocation signals. The mitigation measures (e.g., 
use of sound abatement systems, implementation of clearance and 
shutdown zones) would also minimize received levels such that the 
severity of any behavioral response would be expected to be less than 
exposure to unmitigated noise exposure.
    Any masking or TTS effects are anticipated to be of low-severity. 
First, the frequency range of pile driving, the most impactful activity 
conducted by Dominion Energy in terms of response severity, falls 
within a portion of the frequency range of most odontocete 
vocalizations. However, odontocete vocalizations span a much wider 
range than the low frequency construction activities proposed by 
Dominion Energy. Further, as described above, recent studies suggest 
odontocetes have a mechanism to self-mitigate (i.e., reduce hearing 
sensitivity) the impacts of noise exposure, which could potentially 
reduce TTS impacts (Nachtigall and Supin, 2013; Finneran, 2018). Any 
masking or TTS is anticipated to be limited and would typically only 
interfere with communication within a portion of an odontocete's range 
and as discussed earlier, the effects would only be expected to be of a 
short duration and, for TTS, a relatively small degree. Furthermore, 
odontocete echolocation occurs predominantly at frequencies 
significantly higher than low frequency construction activities; 
therefore, there is little likelihood that threshold shift 
specifically, either temporary or permanent, would interfere with 
feeding behaviors (noting that take by Level A harassment (PTS) is 
proposed for only harbor porpoises (n=2)). For HRG surveys, the sources 
operate at higher frequencies than pile driving; however, sounds from 
these sources attenuate very quickly in the water column, as described 
above, and many of the sources are downward directed; therefore, the 
potential for TTS and masking is very limited. Further, odontocetes 
(e.g., common dolphins, spotted dolphins, bottlenose dolphins) have 
demonstrated an affinity to bow-ride actively surveying HRG surveys; 
therefore, the severity of any harassment, if it does occur, is 
anticipated to be minimal based on the lack of avoidance previously 
demonstrated by these species.
    The waters off the coast of Virginia are used by several odontocete 
species; however, none (except the sperm whale) are listed under the 
ESA and there are no known habitats of particular importance in the 
vicinity of the project. In general, odontocete habitat ranges are far-
reaching along the Atlantic coast of the U.S. and the waters off of 
Virginia and within the continental slope, including the project area, 
do not contain any particularly unique odontocete habitat features.

[[Page 28763]]

Sperm Whales

    The Western North Atlantic stock of sperm whales spans the East 
Coast out into oceanic waters well beyond the U.S. EEZ. Although listed 
as endangered, the primary threat faced by the sperm whale (i.e., 
commercial whaling) has been eliminated and, further, sperm whales in 
the western North Atlantic were little affected by modern whaling 
(Taylor et al., 2008). Current potential threats to the species 
globally include vessel strikes, entanglement in fishing gear, 
anthropogenic noise, exposure to contaminants, climate change, and 
marine debris. There is no currently reported trend for the stock and, 
although the species is listed as endangered under the ESA, there are 
no specific issues with the status of the stock that cause particular 
concern (e.g., no UMEs). There are no known areas of biological 
importance (e.g., critical habitat or BIAs) in or near the project 
area.
    No mortality, serious injury or Level A harassment is anticipated 
or proposed to be authorized for this species. Impacts would be limited 
to Level B harassment and would occur to only a very small number of 
individuals (maximum of 3 in any given year and six total across all 5-
years of the proposed project) incidental to pile driving associated 
with foundation installation and HRG surveys. Sperm whales are not 
common within the project area due to the shallow waters, and it is not 
expected that any noise levels would reach habitat in which sperm 
whales are common, including deep-water foraging habitat. If sperm 
whales do happen to be present in the project area during any 
activities related to the CVOW-C project, they would likely be only 
transient visitors and not engaging in any significant behaviors. This 
very low magnitude and severity of effects is not expected to result in 
impacts on the reproduction or survival of individuals, much less 
impact annual rates of recruitment or survival. For these reasons, we 
have determined, in consideration of all of the effects of Dominion 
Energy's activities combined, that the take proposed to be authorized 
would have a negligible impact on sperm whales.

Dolphins and Small Whales (Inclusive of Delphinid Species, False Killer 
Whale, Melon-Headed Whale, Pygmy Sperm Whale, and Pilot Whales)

    None of the delphinids or small whale species for which take has 
been proposed for authorization are listed as endangered in the ESA. 
Across these species, the maximum amount of incidental take, by Level B 
harassment only, proposed for authorization in any one year ranges 
between 1 (pygmy sperm whale) and 7,360 (for both Atlantic spotted 
dolphins and common dolphins). The number of takes proposed to be 
authorized in the last three years of the rule is notably less and the 
5-year total amount of take (by Level B harassment only) proposed for 
authorization ranges between 2 (pygmy sperm whale) and 26,764 (Atlantic 
spotted dolphin) No mortality, serious injury, or Level A harassment is 
anticipated or proposed to be authorized for any delphinid or small 
whale. There are no recent UMEs, specific areas of known biological 
importance, or other specific issues related to the status of 
odontocete stocks that cause particular concern. Further, though the 
estimated numbers of take are comparatively higher than the numbers for 
mysticetes, we note that for all species they are relatively low 
relative to the population abundance.
    As described above for odontocetes broadly, given the comparatively 
higher amount of estimated takes for some species and the behavioral 
patterns of odontocetes, we anticipate that a fair number of these 
instances of take in a day represent multiple exposures of a smaller 
number of individuals, meaning the actual number of individuals taken 
is lower. Although some amount of repeated exposure to some individuals 
is likely given the duration of activity proposed by Dominion Energy, 
the intensity of any Level B harassment combined with the availability 
of alternate nearby foraging habitat suggests that the likely impacts 
would not impact the reproduction or survival of any individuals.
    Overall, the populations of all delphinid and small whale species 
and stocks for which we propose to authorize take are stable (no 
declining population trends), not facing existing UMEs, and the 
relatively low magnitude and severity of effects is not expected to 
result in impacts on the reproduction or survival of any individuals, 
much less affect annual rates of recruitment or survival. No mortality, 
serious injury or Level A harassment is anticipated or proposed to be 
authorized for any of these species. For these reasons, we have 
preliminarily determined, in consideration of all of the effects of 
Dominion Energy's activities combined, that the take proposed to be 
authorized would have a negligible impact on all delphinid and small 
whale species and stocks considered in this analysis.

Harbor Porpoises

    The Gulf of Maine/Bay of Fundy stock of harbor porpoises is found 
predominantly in northern U.S. coastal waters (less than 150 m depth) 
and up into Canada's Bay of Fundy. This stock of harbor porpoise is not 
listed as endangered under the ESA. The maximum amount of incidental 
take of harbor porpoises proposed for authorization in any year is 1 by 
Level A harassment and 40 by Level B harassment. The number of takes 
proposed to be authorized in the last three years of the rule is 
notably less and the 5-year total amount of harbor porpoise take 
proposed for authorization is 2 by Level A harassment and 141 by Level 
B harassment. The amount of take proposed for authorization is low in 
the context of the population abundance. No serious injury or mortality 
is anticipated or proposed for authorization. Although the population 
trend is not known, there are no UMEs, known areas of biological 
importance, or other factors that specifically cause concern for this 
stock. No mortality or non-auditory injury by WTG and OSS foundation 
installation, or due to any other activities planned by Dominion 
Energy, are anticipated or authorized for this stock.
    Regarding the severity of takes by behavioral Level B harassment, 
because harbor porpoises are particularly sensitive to noise, it is 
likely that a fair number of the responses could be of a more moderate 
nature, particularly to pile driving. In response to pile driving, 
harbor porpoises are likely to avoid the area during construction, as 
previously demonstrated in Tougaard et al. (2009) in Denmark, in Dahne 
et al. (2013) in Germany, and in Vallejo et al. (2017) in the United 
Kingdom, although a study by Graham et al. (2019) may indicate that the 
avoidance distance could decrease over time. However, pile driving is 
primarily scheduled to occur when harbor porpoise abundance is low off 
the coast of Virginia (based on the density values (0.00000) presented 
for both summer (June to August) and fall (September to October)) and, 
given alternative foraging areas, any avoidance of the area by 
individuals is not likely to impact the reproduction or survival of any 
individuals. Given a maximum of two monopile foundations for WTGs would 
be installed on any given day, any behavioral responses would be 
expected to be of relatively short duration.
    With respect to PTS and TTS, the effects on an individual are 
likely relatively low given the frequency bands

[[Page 28764]]

of pile driving (most energy below 2 kHz) compared to harbor porpoise 
hearing (150 Hz to 160 kHz peaking around 40 kHz). Specifically, PTS or 
TTS is unlikely to impact hearing ability in their more sensitive 
hearing ranges, or the frequencies in which they communicate and 
echolocate. Regardless, we have authorized a limited amount of PTS for 
harbor porpoises (n=2), but expect any PTS that may occur to be within 
the very low end of their hearing range where harbor porpoises are not 
particularly sensitive, and any PTS would be of small magnitude. As 
such, any PTS would not interfere with echolocation or communication 
frequencies important for foraging or reproduction.
    No mortality or serious injury of harbor porpoise is anticipated or 
proposed to be authorized. While harbor porpoises are likely to avoid 
the area during any construction activity discussed herein, as 
demonstrated during the construction of European wind farms, the time 
of year in which work would occur is when harbor porpoises are not in 
high abundance, and any work that does occur would not be expected to 
result in the species' abandonment of the waters off of Virginia. The 
low magnitude and low to moderate severity of harassment effects is not 
expected to result in impacts on the reproduction or survival of any 
individuals, let alone have impacts on annual rates of recruitment or 
survival of this stock. No mortality or serious injury is anticipated 
or proposed to be authorized. For these reasons, we have preliminarily 
determined, in consideration of all of the effects of Dominion Energy's 
activities combined, that the proposed authorized take would have a 
negligible impact on the Gulf of Maine/Bay of Fundy stock of harbor 
porpoises.

Pinnipeds (Harbor and Gray Seals)

    Neither the harbor seal nor gray seal are listed as endangered 
under the ESA. The maximum amount of incidental take proposed for 
authorization in any year is 1 by Level A harassment and 83 by Level B 
harassment for each seal species. The number of takes proposed to be 
authorized in the last three years of the rule is notably less than 
this. Further, the 5-year total number of take of each seal species 
proposed for authorization is 2 by Level A harassment and 218 by Level 
B harassment. The amount of take proposed for authorization is low 
relative to the population abundance. No serious injury or mortality is 
anticipated or proposed for authorization. We expect that the majority 
of takes of these two species is from the vibratory and impact 
installation of WTG monopile and OSS jacket foundations. Any takes by 
Level B harassment are expected to be in the form of behavioral 
disturbance, primarily due to temporary avoidance of the Project Area 
during pile driving and HRG survey activities. Some low-level TTS and 
masking may occur and may limit the detection of acoustic cues for 
relatively brief periods of time. As described previously for other 
species, any potential TTS or PTS would be small and limited to a few 
dB. There are no known haul-out locations or other areas of importance 
in or adjacent to the Project Area for either harbor or gray seals.
    These pinniped species occur in Virginia waters in relatively low 
numbers in the summer (0.00001; June to August) and fall (0.00047; 
September to October), as compared to the spring density (0.01828; 
May). Given foundation installation would occur during months primarily 
when pinniped densities are lower, we expect impacts to animals to be 
minimal. Seals are also more likely to be close to shore such that 
exposure to impact pile driving would be expected to be at lower levels 
generally (but still above NMFS behavioral harassment threshold). 
Research and observations show that pinnipeds in the water may be 
tolerant of anthropogenic noise and activity (a review of behavioral 
reactions by pinnipeds to impulsive and non-impulsive noise can be 
found in Richardson et al. (1995) and Southall et al. (2007)). 
Available data, though limited, suggest that exposures between 
approximately 90 and 140 dB SPL do not appear to induce strong 
behavioral responses in pinnipeds exposed to non-pulse sounds in water 
(Costa et al., 2003; Jacobs and Terhune, 2002; Kastelein et al., 
2006c). Although there was no significant displacement during 
construction as a whole, Russell et al. (2016) found that displacement 
did occur during active pile driving at predicted received levels 
between 168 and 178 dB re 1[micro]Pa(p-p); however seal 
distribution returned to the pre-piling condition within two hours of 
cessation of pile driving. Pinnipeds may not react at all until the 
sound source is approaching (or they approach the sound source) within 
a few hundred meters and then may alert, ignore the stimulus, change 
their behaviors, or avoid the immediate area by swimming away or 
diving.
    Effects on pinnipeds that are taken by Level B harassment in the 
CVOW-C project area would likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring). Most likely, individuals 
would simply move away from the sound source and be temporarily 
displaced from those areas (see Lucke et al., 2006; Edren et al., 2010; 
Skeate et al., 2012; Russell et al., 2016). Given their comparatively 
greater documented tolerance of anthropogenic sound (Richardson et al., 
1995; Southall et al., 2007), repeated exposures of individuals of 
either of these species to levels of sound that may cause Level B 
harassment are unlikely to significantly disrupt foraging behavior. 
Given the low anticipated magnitude of impacts from any given exposure, 
even repeated Level B harassment across a few days of some small subset 
of individuals, which could occur, is unlikely to result in impacts on 
the reproduction or survival of any individuals. Moreover, pinnipeds 
would benefit from the mitigation measures described in the Proposed 
Mitigation section.
    As described above, noise from impact pile driving is low frequency 
and, while any PTS that does occur would fall within the lower end of 
pinniped hearing ranges (50 Hz to 86 kHz), it would be of small degree 
and not occur across the entire, or even most sensitive, hearing part 
of the pinniped hearing range. Hence, any impacts from PTS are likely 
to be of low severity and not interfere with behaviors critical to 
reproduction or survival.
    Elevated numbers of harbor seal and gray seal mortalities were 
first observed in July 2018 and occurred across Maine, New Hampshire, 
and Massachusetts until 2020. Based on tests conducted so far, the main 
pathogen found in the seals belonging to that UME was phocine distemper 
virus, although additional testing to identify other factors that may 
be involved in this UME are underway. Currently, the only active UME is 
occurring in Maine with some harbor and gray seals testing positive for 
highly pathogenic avian in[fllig]uenza (HPAI) H5N1. Although elevated 
strandings continue, neither UME (alone or in combination) provide 
cause for concern regarding population-level impacts to any of these 
stocks. For harbor seals, the population abundance is over 75,000 and 
annual M/SI (350) is well below PBR (2,006) (per the draft 2022 SARs 
(88 FR 4162; January 24, 2023)). The population abundance for gray 
seals in the United States is over 27,000, with an estimated overall 
abundance, including seals in Canada, of approximately 450,000. In 
addition, the abundance of gray seals is likely increasing in the U.S. 
Atlantic, as well

[[Page 28765]]

as in Canada (per the draft 2022 SARs (88 FR 4162; January 24, 2023)).
    Overall, impacts from the Level B harassment take proposed for 
authorization incidental to Dominion Energy's specified activities 
would be of relatively low magnitude and a low severity. Similarly, 
while some individuals may incur PTS overlapping some frequencies that 
are used for foraging and communication, given the low degree, the 
impacts would not be expected to impact reproduction or survival of any 
individuals. In consideration of all of the effects of Dominion 
Energy's activities combined, we have preliminarily determined that the 
authorized take will have a negligible impact on harbor seals and gray 
seals.

Preliminary Negligible Impact Determination

    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the marine mammal 
take from all of Dominion Energy's specified activities combined would 
have a negligible impact on all affected marine mammal species or 
stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is less than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    NMFS proposes to authorize incidental take (by Level A harassment 
and Level B harassment) of 21 species of marine mammal (with 22 total 
managed stocks). The maximum number of takes estimated within any one 
year and proposed for authorization relative to the best available 
population abundance is less than one-third for all species and stocks 
potentially impacted (i.e., less than 3 percent for fifteen stocks, 
less than 10 percent for five stocks, and less than 20 percent for one 
stock (see Table 29)). For one species, the melon-headed whale, there 
is no available abundance estimate (Hayes et al., 20220); however, 
given that only 5 takes, by Level B harassment only, are proposed to be 
authorized, the amount of take relative to the population can 
reasonably be considered small. Based on the analysis contained herein 
of the proposed activities (including the proposed mitigation and 
monitoring measures) and the estimated take of marine mammals, NMFS 
preliminarily finds that small numbers of marine mammals may be taken 
relative to the population abundance of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the promulgation of 
rulemakings, NMFS consults internally whenever we propose to authorize 
take for endangered or threatened species, in this case with the NMFS 
Greater Atlantic Regional Field Office (GARFO).
    NMFS is proposing to authorize the take of four marine mammal 
species which are listed under the ESA: the North Atlantic right, sei, 
fin, and sperm whale. The Permit and Conservation Division requested 
initiation of Section 7 consultation on April 4, 2023, with GARFO for 
the issuance of this proposed rulemaking. NMFS will conclude the 
Endangered Species Act consultation prior to reaching a determination 
regarding the proposed issuance of the authorization. The proposed 
regulations and any subsequent LOA(s) would be conditioned such that, 
in addition to measures included in those documents, the applicant 
would also be required to abide by the reasonable and prudent measures 
and terms and conditions of a Biological Opinion and Incidental Take 
Statement, issued by NMFS, pursuant to section 7 of the Endangered 
Species Act.

Proposed Promulgation

    As a result of these preliminary determinations, NMFS proposes to 
promulgate an ITA for Dominion Energy that would authorize take, by 
Level A harassment and Level B harassment, of marine mammals incidental 
to construction activities associated with the CVOW-C project offshore 
of Virginia for a 5-year period from February 5, 2024, through February 
4, 2029, provided the previously mentioned mitigation, monitoring, and 
reporting requirements are incorporated.

Request for Additional Information and Public Comments

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning Dominion Energy's request and the proposed 
regulations (see ADDRESSES). All comments will be reviewed and 
evaluated as we prepare the final rule and make final determinations on 
whether to issue the requested authorization. This proposed rule and 
referenced documents provide all environmental information relating to 
our proposed action for public review.
    Recognizing, as a general matter, that this action is one of many 
current and future wind energy actions, we invite comment on the 
relative merits of the IHA, single-action rule/LOA, and programmatic 
multi-action rule/LOA approaches, including potential marine mammal 
take impacts resulting from this and other related wind energy actions 
and possible benefits resulting from regulatory certainty and 
efficiency.

Classification

    Pursuant to the procedures established to implement Executive Order 
12866, the Office of Management and Budget has determined that this 
proposed rule is not significant.
    Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA), 
the Chief Counsel for Regulation of the Department of Commerce has 
certified to the Chief Counsel for Advocacy of the Small Business 
Administration that this proposed rule, if adopted, would not have a 
significant economic impact on a substantial number of small entities. 
Dominion Energy is the sole entity that would be subject to the 
requirements in these proposed regulations, and Dominion Energy is not 
a small governmental jurisdiction, small organization, or small 
business, as defined by the RFA. Under the RFA,

[[Page 28766]]

governmental jurisdictions are considered to be small if they are 
governments of cities, counties, towns, townships, villages, school 
districts, or special districts, with a population of less than 50,000. 
Because of this certification, a regulatory flexibility analysis is not 
required and none has been prepared.
    Notwithstanding any other provision of law, no person is required 
to respond to nor shall a person be subject to a penalty for failure to 
comply with a collection of information subject to the requirements of 
the Paperwork Reduction Act (PRA) unless that collection of information 
displays a currently valid Office of Management and Budget (OMB) 
control number. These requirements have been approved by OMB under 
control number 0648-0151 and include applications for regulations, 
subsequent LOA, and reports. Send comments regarding any aspect of this 
data collection, including suggestions for reducing the burden, to 
NMFS.
    The Coastal Zone Management Act (CZMA) requires Federal actions 
within and outside the coastal zone that have reasonably foreseeable 
effects on any coastal use or natural resource of the coastal zone be 
consistent with the enforceable policies of a state's federally 
approved coastal management program. 16 U.S.C. 1456(c). Additionally, 
regulations implementing the CZMA require non-Federal applicants for 
Federal licenses or permits to submit a consistency certification to 
the state that declares that the proposed activity complies with the 
enforceable policies of the state's approved management program and 
will be conducted in a manner consistent with such program.
    In 2021, the Virginia Electric and Power Company, doing business as 
Dominion Energy Virginia, submitted a Federal consistency certification 
to the Virginia Department of Environmental Quality (VDEQ) seeking 
concurrence that the construction, operations, and decommissioning 
activities of the proposed CVOW-C project is consistent with the 
enforceable policies of the State's federally approved coastal 
management program. Although no project components are proposed in the 
State of North Carolina or in North Carolina State waters, Dominion 
Energy also submitted a Federal consistency certification to the North 
Carolina Division of Coastal Management. A revised draft of the 
consistency certifications dated May 2022 was prepared and submitted to 
each state and is included as Appendix P of the company's Construction 
and Operation Plan.
    NMFS has determined that Dominion Energy's application for 
authorization to take small numbers of marine mammals incidental to the 
development of the CVOW-C project on the outer continental shelf of the 
Atlantic Ocean is an unlisted activity and, thus, is not, at this time, 
subject to Federal consistency requirements in the absence of the 
receipt and prior approval of an unlisted activity review request from 
the state by the Director of NOAA's Office for Coastal Management. This 
determination does not excuse Dominion Energy from responsibility to 
seek concurrence from VDEQ on other Federal permits, approvals, or 
actions that might be subject to consistency review pursuant to the 
CZMA.

List of Subjects in 50 CFR Part 217

    Administrative practice and procedure, Endangered and threatened 
species, Fish, Fisheries, Marine mammals, Penalties, Reporting and 
recordkeeping requirements, Wildlife.

    Dated: April 24, 2023.
Samuel D. Rauch, III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.

    For reasons set forth in the preamble, NMFS proposes to amend 50 
CFR part 217 as follows:

PART 217--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS

0
1. The authority citation for part 217 continues to read as follows:

    Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.

0
2. Add subpart DD, consisting of Sec. Sec.  [thinsp]217.290 through 
217.299, to read as follows:

Subpart DD--Taking Marine Mammals Incidental to the Coastal 
Virginia Offshore Wind Commercial Project Offshore Virginia

Sec.
217.290 Specified activity and specified geographical region.
217.291 Effective dates.
217.292 Permissible methods of taking.
217.293 Prohibitions.
217.294 Mitigation requirements.
217.295 Requirements for monitoring and reporting.
217.296 Letter of Authorization.
217.297 Modifications of Letter of Authorization.
217.298--217.299 [Reserved]

Subpart DD--Taking Marine Mammals Incidental to the Coastal 
Virginia Offshore Wind Commercial Project Offshore Virginia


Sec.  217.290  Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to the taking of marine 
mammals that occurs incidental to activities associated with 
construction of the Coastal Virginia Offshore Wind Commercial (CVOW-C) 
project by Virginia Electric and Power Company, doing business as 
Dominion Energy Virginia (Dominion Energy), and those persons it 
authorizes or funds to conduct activities on its behalf in the area 
outlined in paragraph (b) of this section.
    (b) The taking of marine mammals by Dominion Energy may be 
authorized in a Letter of Authorization (LOA) only if it occurs in the 
Bureau of Ocean Energy Management (BOEM) Lease Area Outer Continental 
Shelf (OCS)-A-0483 Commercial Lease of Submerged Lands for Renewable 
Energy Development, along export cable routes, and at the sea-to-shore 
transition points west of the firing range at the State Military 
Reservation in Virginia Beach, Virginia.
    (c) The taking of marine mammals by Dominion Energy is only 
authorized if it occurs incidental to the following activities 
associated with the CVOW-C project: installation of up to 176 wind 
turbine generator (WTG) and 3 offshore substation (OSS) foundations by 
impact and vibratory pile driving, impact and vibratory pile driving 
associated with cable landfall construction; and high-resolution 
geophysical (HRG) site characterization surveys.


Sec.  217.291  Effective dates.

    Regulations in this subpart are effective from February 5, 2024, 
through February 4, 2029.


Sec.  217.292  Permissible methods of taking.

    Under an LOA, issued pursuant to Sec. Sec.  216.106 of this chapter 
and 217.296, Dominion Energy, and those persons it authorizes or funds 
to conduct activities on its behalf, may incidentally, but not 
intentionally, take marine mammals within the area described in Sec.  
217.290(b) in the following ways, provided Dominion Energy is in 
complete compliance with all terms, conditions, and requirements of the 
regulations in this subpart and the appropriate LOA:
    (a) By Level B harassment associated with the acoustic disturbance 
of marine mammals by impact and vibratory pile driving (WTG and OSS 
foundation installation), impact and vibratory pile

[[Page 28767]]

driving during cable landfall construction (temporary goal posts and 
temporary cofferdams), and HRG site characterization surveys; and
    (b) By Level A harassment associated with the acoustic disturbance 
of marine mammals by impact pile driving WTG and OSS foundations.
    (c) Take by mortality or serious injury of any marine mammal 
species is not authorized; and
    (d) The incidental take of marine mammals by the activities listed 
in paragraphs (a) and (b) of this section is limited to the following 
species:

                        Table 1 to Paragraph (d)
------------------------------------------------------------------------
      Marine mammal species         Scientific name          Stock
------------------------------------------------------------------------
Fin whale.......................  Balaenoptera        Western North
                                   physalus.           Atlantic.
Sei whale.......................  Balaenoptera        Nova Scotia.
                                   borealis.
Minke whale.....................  Balaenoptera        Canadian East
                                   acutorostrata.      Coastal.
North Atlantic right whale......  Eubalaena           Western North
                                   glacialis.          Atlantic.
Humpback whale..................  Megaptera           Gulf of Maine.
                                   novaeangliae.
Sperm whale.....................  Physeter            North Atlantic.
                                   macrocephalus.
Atlantic spotted dolphin........  Stenella frontalis  Western North
                                                       Atlantic.
Atlantic white-sided dolphin....  Lagenorhynchus      Western North
                                   acutus.             Atlantic.
Bottlenose dolphin..............  Tursiops truncatus  Western North
                                                       Atlantic--Offshor
                                                       e.
                                  ..................  Southern Migratory
                                                       Coastal.
Clymene dolphin.................  Stenella clymene..  Western North
                                                       Atlantic.
Common dolphin..................  Delphinus delphis.  Western North
                                                       Atlantic.
False killer whale..............  Pseudorca           Western North
                                   crassidens.         Atlantic.
Harbor porpoise.................  Phocoena phocoena.  Gulf of Maine/Bay
                                                       of Fundy.
Melon-headed whale..............  Peponocephala       Western North
                                   electra.            Atlantic.
Long-finned pilot whale.........  Globicephala melas  Western North
                                                       Atlantic.
Pantropical spotted dolphin.....  Stenella attenuata  Western North
                                                       Atlantic.
Pygmy sperm whale...............  Kogia breviceps...  Western North
                                                       Atlantic.
Short-finned pilot whale........  Globicephala        Western North
                                   macrorhynchus.      Atlantic.
Risso's dolphin.................  Grampus griseus...  Western North
                                                       Atlantic.
Gray seal.......................  Halichoerus grypus  Western North
                                                       Atlantic.
Harbor seal.....................  Phoca vitulina....  Western North
                                                       Atlantic.
------------------------------------------------------------------------

Sec.  217.293  Prohibitions.

    Except for the takings described in Sec.  217.292 and authorized by 
an LOA issued under Sec.  217.296 or Sec.  217.297, it is unlawful for 
any person to do any of the following in connection with the activities 
described in this subpart:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or an LOA issued under Sec. Sec.  217.296 
and 217.297;
    (b) Take any marine mammal not specified in Sec.  217.292(d);
    (c) Take any marine mammal specified in the LOA in any manner other 
than as specified in the LOA; or
    (d) Take any marine mammal specified in Sec.  217.292(d), after 
NMFS determines such taking results in more than a negligible impact on 
the species or stocks of such marine mammals.


Sec.  217.294  Mitigation requirements.

    When conducting the activities identified in Sec. Sec.  217.290 and 
217.292, Dominion Energy must implement the mitigation measures 
contained in this section and any LOA issued under Sec. Sec.  217.296 
and 217.297. These mitigation measures include, but are not limited to:
    (a) General conditions. The following measures apply to the CVOW-C 
Project:
    (1) A copy of any issued LOA must be in the possession of Dominion 
Energy and its designees, all vessel operators, visual protected 
species observers (PSOs), passive acoustic monitoring (PAM) operators, 
pile driver operators, and any other relevant designees operating under 
the authority of the issued LOA.
    (2) Dominion Energy must conduct briefings between construction 
supervisors, construction crews, and the PSO and PAM team prior to the 
start of all construction activities, and when new personnel join the 
work, in order to explain responsibilities, communication procedures, 
marine mammal monitoring and reporting protocols, and operational 
procedures. A simple guide must be included with the Marine Mammal 
Monitoring Plan to aid personnel in identifying species if they are 
observed in the vicinity of the project area.
    (3) Prior to and when conducting any in-water construction 
activities and vessel operations, Dominion Energy personnel (e.g., 
vessel operators, PSOs) must use available sources of information on 
North Atlantic right whale presence in or near the project area 
including daily monitoring of the Right Whale Sightings Advisory 
System, and monitoring of Coast Guard VHF Channel 16 throughout the day 
to receive notification of any sightings and/or information associated 
with any Slow Zones (i.e., Dynamic Management Areas (DMAs) and/or 
acoustically-triggered slow zones) to provide situational awareness for 
both vessel operators and PSO.
    (4) Dominion Energy must ensure that any visual observations of an 
Endangered Species Act (ESA)-listed marine mammal are communicated to 
PSOs and vessel captains during the concurrent use of multiple project-
associated vessels (of any size; e.g., construction surveys, crew/
supply transfers, etc.).
    (5) Dominion Energy must establish and implement clearance and 
shutdown zones as described in the LOA.
    (6) Dominion Energy must instruct all vessel personnel regarding 
the authority of the PSO(s). Any disagreement between the Lead PSO and 
the vessel operator would only be discussed after shutdown has 
occurred.
    (7) If an individual from a species for which authorization has not 
been granted, or a species for which authorization has been granted but 
the authorized take number has been met, is observed entering or within 
the relevant Level B harassment zone for a specified activity, pile 
driving and HRG acoustic sources must be shut down immediately, unless 
shutdown would result in imminent risk of injury or loss of life to an 
individual, pile refusal, or pile instability, or be delayed if the 
activity has not commenced. Impact and vibratory pile driving and 
initiation of

[[Page 28768]]

HRG acoustic sources must not commence or resume until the animal(s) 
has been confirmed to have left the relevant clearance zone or the 
observation time has elapsed with no further sightings.
    (8) Construction and survey activities shall only commence when 
visual clearance zones are fully visible (e.g., not obscured by 
darkness, rain, fog, etc.) and clear of marine mammals, as determined 
by the Lead PSO, for at least 30 minutes immediately prior to 
initiation of equipment (i.e., vibratory and impact pile driving, HRG 
surveys that use boomers, sparkers, and Compressed High-Intensity 
Radiated Pulses (CHIRPs)).
    (9) Any visual or acoustic detection within the clearance or 
shutdown zones must trigger a delay to the commencement of construction 
and survey activities. Any marine mammals observed within a clearance 
or shutdown zone must be allowed to remain in the area (i.e., must 
leave of their own volition) prior to commencing pile driving 
activities or HRG surveys.
    (10) Dominion Energy must treat any large whale sighted by a PSO or 
acoustically detected by a PAM operator as if it were a North Atlantic 
right whale and apply the mitigation measures applicable to North 
Atlantic right whales, unless a PSO or a PAM operator confirms the 
large whale is another type of whale.
    (11) Following a shutdown, construction and survey activities shall 
not recommence until the minimum visibility zone is fully visible and 
clear of marine mammals for 30 minutes and no marine mammals have been 
detected acoustically within the PAM clearance zone for 30 minutes.
    (12) For in-water construction heavy machinery activities, other 
than impact and vibratory pile driving, if a marine mammal is on a path 
towards or comes within 10 m of equipment, Dominion Energy must cease 
operations until the marine mammal has moved more than 10 m on a path 
away from the activity to avoid direct interaction with equipment.
    (13) All vessels must be equipped with an Automatic Identification 
System (AIS) and Dominion Energy must report all Maritime Mobile 
Service Identify (MMSI) numbers to NMFS Office of Protected Resources 
prior to initiating in-water activities.
    (b) Vessel strike avoidance measures. The following measures apply 
to all vessels associated with the CVOW-C:
    (1) Prior to the start of construction activities, all vessel 
operators and crew must receive a protected species identification 
training that covers, at a minimum:
    (i) Identification of marine mammals and other protected species 
known to occur or which have the potential to occur in the Dominion 
Energy project area;
    (ii) Training on making observations in both good weather 
conditions (i.e., clear visibility, low winds, low sea states) and bad 
weather conditions (i.e., fog, high winds, high sea states, with 
glare);
    (iii) Training on information and resources available to the 
project personnel regarding the applicability of Federal laws and 
regulations for protected species;
    (iv) Observer training related to vessel strike avoidance measures 
must be conducted for all vessel operators and crew prior to the start 
of in-water construction activities; and
    (v) Confirmation of marine mammal observer training must be 
documented on a training course log sheet and reported to NMFS;
    (2) All vessel operators and crews, regardless of their vessel's 
size, must maintain a vigilant watch for all marine mammals and slow 
down, stop their vessel, or alter course, as appropriate, to avoid 
striking any marine mammal;
    (3) All vessels must have a visual observer on board who is 
responsible for monitoring the vessel strike avoidance zone for marine 
mammals. Visual observers may be a PSO or crew member, but crew members 
responsible for these duties must be provided sufficient training by 
Dominion Energy to distinguish marine mammals from other types of 
animals or objects and must be able to identify a marine mammal as a 
North Atlantic right whale, other whale (defined in this context as 
sperm whales or baleen whales other than North Atlantic right whales), 
or other marine mammal. Crew members serving as visual observers must 
not have duties other than observing for marine mammals while the 
vessel is operating over 10 knots (kts);
    (4) Year-round and when a vessel is in transit, all vessel 
operators must continuously monitor U.S. Coast Guard VHF Channel 16, 
over which North Atlantic right whale sightings are broadcasted. At the 
onset of transiting and at least once every four hours, vessel 
operators and/or trained crew members must monitor the project's 
Situational Awareness System, WhaleAlert, and the Right Whale Sighting 
Advisory System (RWSAS) for the presence of North Atlantic right 
whales. Any observations of any large whale by any Dominion Energy 
staff or contractors, including vessel crew, must be communicated 
immediately to PSOs, PAM operator, and all vessel captains to increase 
situational awareness. Conversely, any large whale observation or 
detection via a sighting network (e.g., Mysticetus) by PSOs or PAM 
operators must be conveyed to vessel operators and crew;
    (5) Any observations of any large whale by any Dominion Energy 
staff or contractor, including vessel crew, must be communicated 
immediately to PSOs and all vessel captains to increase situational 
awareness;
    (6) Nothing in this subpart exempts vessels from applicable speed 
regulations at 50 CFR 224.105;
    (7) All vessels must transit active Slow Zones (i.e., Dynamic 
Management Areas (DMAs) or acoustically-triggered slow zone), and 
Seasonal Management Areas (SMAs) at 10 kts or less;
    (8) Between November 1st and April 30th, all vessels must transit 
at 10 kts or less;
    (9) All vessels, regardless of size, must immediately reduce speed 
to 10 kts or less when any large whale, mother/calf pairs, or large 
assemblages of non-delphinid cetaceans are observed (within 500 m) of 
an underway vessel;
    (10) All vessels, regardless of size, must immediately reduce speed 
to 10 kts or less when a North Atlantic right whale is sighted, at any 
distance, by anyone on the vessel;
    (11) All transiting vessels operating at any speed must have a 
dedicated visual observer on duty at all times to monitor for marine 
mammals within a 180 degree direction of the forward path of the vessel 
(90 degrees port to 90 degree starboards) located at the best vantage 
point for ensuring vessels are maintaining appropriate separation 
distances from marine mammals. Visual observers must be equipped with 
alternative monitoring technology for periods of low visibility (e.g., 
darkness, rain, fog, etc.). The dedicated visual observer must receive 
prior training on protected species detection and identification, 
vessel strike minimization procedures, how and when to communicate with 
the vessel captain, and reporting requirements. Visual observers may be 
third-party observers (i.e., NMFS-approved PSOs) or crew members. 
Observer training related to these vessel strike avoidance measures 
must be conducted for all vessel operators and crew prior to the start 
of vessel use;
    (12) All vessels must maintain a minimum separation distance of 500 
m from North Atlantic right whales. If underway and making way, all 
vessels must steer a course away from any

[[Page 28769]]

sighted North Atlantic right whale at 10 kts or less such that the 500-
m minimum separation distance requirement is not violated. If a North 
Atlantic right whale is sighted within 500 m of a transiting vessel, 
that vessel must shift the engine to neutral. Engines must not be 
engaged until the whale has moved outside of the vessel's path and 
beyond 500 m. If a whale is observed but cannot be confirmed as a 
species other than a North Atlantic right whale, the vessel operator 
must assume that it is a North Atlantic right whale;
    (13) All vessels must maintain a minimum separation distance of 100 
m from sperm whales and baleen whales other than North Atlantic right 
whales. If one of these species is sighted within 100 m of a transiting 
vessel, that vessel must shift the engine to neutral. Engines must not 
be engaged until the whale has moved outside of the vessel's path and 
beyond 100 m;
    (14) All vessels must maintain a minimum separation distance of 50 
m from all delphinoid cetaceans and pinnipeds, with an exception made 
for those that approach the vessel (e.g., bow-riding dolphins). If a 
delphinid cetacean or pinniped is sighted within 50 m of a transiting 
vessel, that vessel must shift the engine to neutral, with an exception 
made for those that approach the vessel (e.g., bow-riding dolphins). 
Engines must not be engaged until the animal(s) has moved outside of 
the vessel's path and beyond 50 m;
    (15) When a marine mammal(s) is sighted while a vessel is 
transiting, the vessel must take action as necessary to avoid violating 
the relevant separation distances (e.g., attempt to remain parallel to 
the animal's course, avoid excessive speed or abrupt changes in 
direction until the animal has left the area). If a marine mammal(s) is 
sighted within the relevant separation distance, the vessel must shift 
the engine to neutral and not engage the engine(s) until the animal(s) 
outside and on a path away from the separation area. This does not 
apply to any vessel towing gear or any situation where respecting the 
relevant separation distance would be unsafe (i.e., any situation where 
the vessel is navigationally constrained);
    (16) All vessels underway must not divert or alter course to 
approach any marine mammal. If a separation distance is triggered, any 
vessel underway must avoid abrupt changes in course direction and 
transit at 10 kts or less until the animal is outside the relevant 
separation distance; and
    (17) Dominion Energy must submit a North Atlantic right whale 
vessel strike avoidance plan 180 days prior to the commencement of 
vessel use. This plan must describe, at a minimum, how PAM, in 
combination with visual observations, would be conducted to ensure the 
transit corridor is clear of right whales and would also provide 
details on the vessel-based observer protocols on transiting vessels.
    (c) WTG and OSS foundation installation. The following requirements 
apply to pile driving activities associated with the installation of 
WTG and OSS foundations:
    (1) Foundation vibratory and impact pile driving may not occur 
November 1st through April 30th;
    (2) Monopiles must be no larger than 9.5-m in diameter, 
representing the larger end of the tapered 9.5/7.5-m monopile design. 
Pin piles must be no larger than 2.8-m in diameter. During all monopile 
and pin pile installation, the minimum amount of hammer energy 
necessary to effectively and safely install and maintain the integrity 
of the piles must be used. Hammer energies must not exceed 4,000 
kilojoules (kJ) for monopile installations and 3,000 kJ for pin pile 
installation. No more than two monopile foundation or two pin piles for 
jacket foundations may be installed per day;
    (3) Dominion Energy must not initiate pile driving earlier than 1 
hour after civil sunrise or later than 1.5 hours prior to civil sunset, 
unless Dominion Energy submits, and NMFS approves an Alternative 
Monitoring Plan as part of the Pile Driving and Marine Mammal 
Monitoring Plan that reliably demonstrates the efficacy of their night 
vision devices;
    (4) Dominion Energy must utilize a soft-start protocol for each 
impact pile driving event of all monopiles and pin piles by performing 
4-6 strikes per minute at 10 to 20 percent of the maximum hammer 
energy, for a minimum of 20 minutes;
    (5) Soft-start must occur at the beginning of monopile and pin pile 
installation and at any time following a cessation of impact pile 
driving of 30 minutes or longer;
    (6) If a marine mammal is detected, visually or acoustically, 
within or about to enter the applicable clearance zones, prior to the 
beginning of soft-start procedures, impact pile driving must be delayed 
until the animal has been visually observed exiting the clearance zone 
or until a specific time period has elapsed with no further sightings. 
The specific time periods are 15 minutes for small odontocetes and 
pinnipeds and 30 minutes for all other species;
    (7) Dominion Energy must deploy dual noise abatement systems that 
are capable of achieving, at a minimum, 10 decibel (dB) of sound 
attenuation, during all vibratory and impact pile driving of monopiles 
and pin piles and comply with the following requirements related noise 
abatement:
    (i) A single bubble curtain must not be used unless paired with 
another noise attenuation device;
    (ii) A big double bubble curtain may be used without being paired 
with another noise attenuation device;
    (iii) The bubble curtain(s) must distribute air bubbles using an 
air flow rate of at least 0.5 m\3\/(min*m). The bubble curtain(s) must 
surround 100 percent of the piling perimeter throughout the full depth 
of the water column. In the unforeseen event of a single compressor 
malfunction, the offshore personnel operating the bubble curtain(s) 
must make appropriate adjustments to the air supply and operating 
pressure such that the maximum possible sound attenuation performance 
of the bubble curtain(s) is achieved;
    (iv) The lowest bubble ring must be in contact with the seafloor 
for the full circumference of the ring, and the weights attached to the 
bottom ring must ensure 100-percent seafloor contact;
    (v) No parts of the ring or other objects may prevent full seafloor 
contact;
    (vi) Construction contractors must train personnel in the proper 
balancing of airflow to the ring. Construction contractors must submit 
an inspection/performance report for approval by Dominion Energy within 
72 hours following the performance test. Dominion Energy must then 
submit that report to NMFS; and
    (vii) Corrections to the bubble ring(s) to meet the performance 
standards in this paragraph (c)(7) must occur prior to impact pile 
driving of monopiles and pin piles. If Dominion Energy uses a noise 
mitigation device in addition to the bubble curtain, Dominion Energy 
must maintain similar quality control measures as described in this 
paragraph (c)(7);
    (8) Dominion Energy must conduct sound field verification (SFV) 
during all vibratory and impact pile driving of the first three 
monopiles and all piles associated with the first OSS foundation 
installed. Subsequent SFV is required should additional piles be driven 
that are anticipated to produce louder sound fields than those 
previously measured;
    (9) Dominion Energy must conduct SFV after construction is complete 
to estimate turbine operational source levels based on measurements in 
the near and far-field at a minimum of three locations from each 
foundation

[[Page 28770]]

monitored. These data must be used to also identify estimated 
transmission loss rates;
    (10) Dominion Energy must submit a sound field verification (SFV) 
plan to NOAA Fisheries for review and approval at least 180 days prior 
to planned start of pile driving that identifies how Dominion Energy 
will comply with the following requirements:
    (i) Dominion Energy must empirically determine source levels, the 
ranges to the isopleths corresponding to the Level A harassment and 
Level B harassment thresholds in meters, and the transmission loss 
coefficient(s). Dominion Energy may estimate ranges to the Level A 
harassment and Level B harassment isopleths by extrapolating from in 
situ measurements conducted at several distances from the piles 
monitored;
    (ii) Dominion Energy must perform sound field measurements at four 
distances from the pile being driven, including, but not limited to, 
750 m and the modeled Level B harassment zones to verify the accuracy 
of those modeled zones;
    (iii) The recordings must be continuous throughout the duration of 
all impact and vibratory hammering of each pile monitored;
    (iv) The measurement systems must have a sensitivity appropriate 
for the expected sound levels from pile driving received at the nominal 
ranges throughout the installation of the pile;
    (v) The frequency range of the system must cover the range of at 
least 20 hertz (Hz) to 20 kilohertz (kHz);
    (vi) The system will be designed to have omnidirectional 
sensitivity and will be designed so that the predicted broadband 
received level of all impact pile-driving strikes exceeds the system 
noise floor by at least 10 dB. The dynamic range of the system must be 
sufficient such that at each location, pile driving signals are not 
clipped and are not masked by noise floor; and
    (vii) Identify operational noise levels and transmission loss 
rates;
    (11) If acoustic field measurements collected during installation 
of foundation piles indicate ranges to the isopleths, corresponding to 
Level A harassment and Level B harassment thresholds, are greater than 
the ranges predicted by modeling (assuming 10 dB attenuation), Dominion 
Energy must implement additional noise mitigation measures prior to 
installing the next monopile. Each modification must be evaluated 
empirically by acoustic field measurements;
    (12) In the event that field measurements indicate ranges to 
isopleths, corresponding to Level A harassment and Level B harassment 
thresholds, are greater than the ranges predicted by modeling (assuming 
10 dB attenuation), NMFS may expand the relevant harassment, clearance, 
and shutdown zones and associated monitoring protocols;
    (13) If the harassment zones are expanded beyond an additional 
1,500 m, additional PSOs must be deployed on additional platforms, with 
each observer responsible for maintaining watch in no more than 180 
degrees and of an area with a radius no greater than 1,500 m;
    (14) If acoustic measurements indicate that ranges to isopleths 
corresponding to the Level A harassment and Level B harassment 
thresholds are less than the ranges predicted by modeling (assuming 10 
dB attenuation), Dominion Energy may request to NMFS a modification of 
the clearance and shutdown zones for impact pile driving of monopiles 
and pin piles;
    (15) For NMFS to consider a modification request for reduced zone 
sizes, Dominion Energy must have had to conduct SFV on three or more 
monopiles and four or more pin piles to verify that zone sizes are 
consistently smaller than those predicted by modeling (assuming 10 dB 
attenuation) and subsequent piles would be installed within and under 
similar conditions (e.g., monitoring data collected during installation 
of a typical pile cannot be used to adjust difficult-to-drive pile 
ranges);
    (16) If a subsequent monopile installation location is selected 
that was not represented by the previous three locations (i.e., 
substrate composition, water depth), SFV is required;
    (17) Dominion Energy must utilize, at minimum, four PSOs who must 
be actively observing for marine mammals before, during, and after pile 
driving. At least two PSOs must be stationed on the primary pile 
driving vessel and at least two PSOs must be stationed on a secondary, 
dedicated PSO vessel. The dedicated PSO vessel must be positioned 
approximately 3 km from the pile being driven and must circle the pile 
at a speed of less than 10 knots;
    (18) PSOs must be able to visually clear (i.e., confirm no marine 
mammals are present) an area that extends around the pile being driven 
as described in the LOA. The entire minimum visibility zone must be 
visible (i.e., not obscured by dark, rain, fog, etc.) for a full 30 
minutes immediately prior to commencing vibratory and impact pile 
driving (2,000 m);
    (19) PSOs must visually monitor clearance zones for marine mammals 
for a minimum of 60 minutes prior to commencing pile driving. Prior to 
initiating soft-start procedures, all clearance zones must be visually 
confirmed to be free of marine mammals for 30 minutes before pile 
driving can begin;
    (20) At least one PAM operator must review data from at least 24 
hours prior to pile driving and actively monitor hydrophones for 60 
minutes prior to pile driving. All clearance zones must be acoustically 
confirmed to be free of marine mammals for 60 minutes before activities 
can begin immediately prior to starting a soft-start of impact pile 
driving;
    (21) If a marine mammal is observed entering or within the relevant 
clearance zone prior to the initiation of vibratory and/or impact pile 
driving activities, pile driving must be delayed and must not begin 
until either the marine mammal(s) has voluntarily left the specific 
clearance zones and have been visually or acoustically confirmed beyond 
that clearance zone, or, when specific time periods have elapsed with 
no further sightings or acoustic detections. The specific time periods 
are 15 minutes for small odontocetes and 30 minutes for all other 
marine mammal species;
    (22) For North Atlantic right whales, any acoustic detection must 
trigger a delay to the commencement of pile driving. The clearance zone 
may only be declared clear if no confirmed North Atlantic right whale 
acoustic detections (in addition to visual) have occurred within the 
PAM clearance zone during the 60-minute monitoring period. Any large 
whale sighting by a PSO or detected by a PAM operator that cannot be 
identified by species must be treated as if it were a North Atlantic 
right whale;
    (23) If a marine mammal is observed entering or within the 
respective shutdown zone, as defined in the LOA, after pile driving has 
begun, the PSO must call for a temporary shutdown of pile driving;
    (24) Dominion Energy must immediately cease pile driving when a 
marine mammal is detected within a shutdown zone, unless shutdown is 
not practicable due to imminent risk of injury or loss of life to an 
individual, pile refusal, or pile instability. In this situation, 
Dominion Energy must reduce hammer energy to the lowest level 
practicable and the reason(s) for not shutting down must be documented 
and reported to NMFS;
    (25) If pile driving has been shut down due to the presence of a 
North Atlantic right whale, pile driving may not restart until the 
North Atlantic right

[[Page 28771]]

whale is no longer observed or 30 minutes has elapsed since the last 
detection;
    (26) Upon restarting impact pile driving, soft-start protocols must 
be followed; and
    (27) Pile driving must not restart until either the marine 
mammal(s) has voluntarily left the specific clearance zones and has 
been visually or acoustically confirmed beyond that clearance zone, or, 
when specific time periods have elapsed with no further sightings or 
acoustic detections have occurred. The specific time periods are 15 
minutes for small odontocetes and 30 minutes for all other marine 
mammal species. In cases where these criteria are not met, pile driving 
may restart only if necessary to maintain pile stability at which time 
Dominion Energy must use the lowest hammer energy practicable to 
maintain stability.
    (d) Cable landfall construction. The following requirements apply 
to cable landfall pile driving activities:
    (1) Dominion Energy must conduct pile driving during daylight hours 
only.
    (2) Dominion Energy must have a minimum of two PSOs on active duty 
during any installation and removal of the temporary cofferdams and 
goal posts. PSOs must be located at the best vantage point(s) on the 
pile driving platform or secondary platform in the immediate vicinity 
of the pile driving platform, in order to ensure that appropriate 
visual coverage is available for the entire visual clearance zone and 
as much of the Level B harassment zone, as possible.
    (3) Prior to the start of pile driving activities, at least two 
PSOs must monitor the clearance zone for 30 minutes, continue 
monitoring during pile driving and for 30 minutes post-pile driving.
    (4) If a marine mammal(s) is observed entering or is observed 
within the clearance zones, pile driving must not commence until the 
animal(s) has exited the zone or a specific amount of time has elapsed 
since the last sighting. The specific time periods are 15 minutes for 
small odontocetes and pinnipeds and 30 minutes for all other marine 
mammal species.
    (5) If a marine mammal is observed entering or within the 
respective shutdown zone, as defined in the LOA, after pile driving has 
begun, the PSO must call for a temporary shutdown of pile driving.
    (6) Dominion Energy must immediately cease pile driving when a 
marine mammal is detected within a shutdown zone, unless shutdown is 
not practicable due to imminent risk of injury or loss of life to an 
individual, pile refusal, or instability. In this situation, Dominion 
Energy must reduce hammer energy to the lowest level practicable and 
the reason(s) for not shutting down must be documented and reported to 
NMFS.
    (7) Pile driving must not restart until either the marine mammal(s) 
has voluntarily left the specific clearance zones and has been visually 
or acoustically confirmed beyond that clearance zone, or, when specific 
time periods have elapsed with no further sightings or acoustic 
detections have occurred. The specific time periods are 15 minutes for 
small odontocetes and pinnipeds and 30 minutes for all other marine 
mammal species. In cases where the criteria in this paragraph (e)(7) is 
not met, pile driving may restart only if necessary to maintain pile 
stability at which time Dominion Energy must use the lowest hammer 
energy practicable to maintain stability.
    (8) If pile driving has been shut down due to the presence of a 
North Atlantic right whale, pile driving may not restart until the 
North Atlantic right whale is no longer observed or 30 minutes has 
elapsed since the last detection.
    (9) Dominion Energy must employ a soft-start for all impact pile 
driving. Soft start requires contractors to provide an initial set of 
three strikes at reduced energy, followed by a 30-second waiting 
period, then two subsequent reduced-energy strike sets.
    (e) HRG surveys. The following requirements apply to HRG surveys 
operating sub bottom profilers (SBPs):
    (1) Dominion Energy is required to have at least one PSO on active 
duty per vessel during HRG surveys that are conducted during daylight 
hours (i.e., from 30 minutes prior to civil sunrise through 30 minutes 
following civil sunset) and at least two PSOs on active duty per vessel 
during HRG surveys that are conducted during nighttime hours.
    (2) Dominion Energy must deactivate acoustic sources during periods 
where no data are being collected, except as determined to be necessary 
for testing. Unnecessary use of the acoustic source(s) is prohibited.
    (3) Dominion Energy is required to ramp-up sub-bottom profilers 
(SBPs) prior to commencing full power, unless the equipment operates on 
a binary on/off switch. ensure visual clearance zones are fully visible 
(e.g., not obscured by darkness, rain, fog, etc.) and clear of marine 
mammals, as determined by the Lead PSO, for at least 30 minutes 
immediately prior to the initiation of survey activities using acoustic 
sources specified in the LOA.
    (4) Prior to a ramp-up procedure starting or activating SBPs, the 
operator must notify the Lead PSO of the planned start time. This 
notification time must not be less than 60 minutes prior to the planned 
ramp-up or activation as all relevant PSOs must monitor the clearance 
zone for 30 minutes prior to the initiation of ramp-up or activation.
    (5) Prior to starting the survey and after receiving confirmation 
from the PSOs that the clearance zone is clear of any marine mammals, 
Dominion Energy must ramp-up sources to half power for 5 minutes and 
then proceed to full power, unless the source operates on a binary on/
off switch in which case ramp-up is not required. Ramp-up and 
activation must be delayed if a marine mammal(s) enters its respective 
shutdown zone. Ramp-up and activation may only be reinitiated if the 
animal(s) has been observed exiting its respective shutdown zone or 
until 15 minutes for small odontocetes and pinnipeds, and 30 minutes 
for all other species, has elapsed with no further sightings.
    (6) Dominion Energy must implement a 30-minute clearance period of 
the clearance zones immediately prior to the commencing of the survey 
or when there is more than a 30 minute break in survey activities or 
PSO monitoring. A clearance period is a period when no marine mammals 
are detected in the relevant zone.
    (7) If a marine mammal is observed within a clearance zone during 
the clearance period, ramp-up or acoustic surveys may not begin until 
the animal(s) has been observed voluntarily exiting its respective 
clearance zone or until a specific time period has elapsed with no 
further sighting. The specific time period is 15 minutes for small 
odontocetes and seals, and 30 minutes for all other species.
    (8) Any large whale sighted by a PSO within 1 km of the SBP that 
cannot be identified by species must be treated as if it were a North 
Atlantic right whale and Dominion Energy must apply the mitigation 
measure applicable to this species.
    (9) In any case when the clearance process has begun in conditions 
with good visibility, including via the use of night vision equipment 
(infrared (IR)/thermal camera), and the Lead PSO has determined that 
the clearance zones are clear of marine mammals, survey operations 
would be allowed to commence (i.e., no delay is required) despite 
periods of inclement weather and/or loss of daylight.
    (10) Once the survey has commenced, Dominion Energy must shut down 
SBPs if a marine mammal enters a respective shutdown zone, except in 
cases when the shutdown zones become obscured

[[Page 28772]]

for brief periods due to inclement weather, survey operations would be 
allowed to continue (i.e., no shutdown is required) so long as no 
marine mammals have been detected. The shutdown requirement does not 
apply to small delphinids of the following genera: Delphinus, Stenella, 
Lagenorhynchus, and Tursiops. If there is uncertainty regarding the 
identification of a marine mammal species (i.e., whether the observed 
marine mammal belongs to one of the delphinid genera for which shutdown 
is waived), the PSOs must use their best professional judgment in 
making the decision to call for a shutdown. Shutdown is required if a 
delphinid that belongs to a genus other than those specified in this 
paragraph (e)(10) is detected in the shutdown zone.
    (11) If SBPs have been shut down due to the presence of a marine 
mammal, the use of SBPs may not commence or resume until the animal(s) 
has been confirmed to have left the Level B harassment zone or until a 
full 15 minutes (for small odontocetes and seals) or 30 minutes (for 
all other marine mammals) have elapsed with no further sighting.
    (12) Dominion Energy must immediately shutdown any SBP acoustic 
source if a marine mammal is sighted entering or within its respective 
shutdown zones. If there is uncertainty regarding the identification of 
a marine mammal species (i.e., whether the observed marine mammal 
belongs to one of the delphinid genera for which shutdown is waived), 
the PSOs must use their best professional judgment in making the 
decision to call for a shutdown. Shutdown is required if a delphinid 
that belongs to a genus other than those specified in this paragraph 
(e)(12) is detected in the shutdown zone.
    (13) If a SBP is shut down for reasons other than mitigation (e.g., 
mechanical difficulty) for less than 30 minutes, it would be allowed to 
be activated again without ramp-up only if:
    (i) PSOs have maintained constant observation; and
    (ii) No additional detections of any marine mammal occurred within 
the respective shutdown zones.
    (f) Fisheries monitoring surveys. The following measures apply to 
fishery monitoring surveys using trap/pot gear:
    (1) All captains and crew conducting fishery surveys must be 
trained in marine mammal detection and identification. Marine mammal 
monitoring will be conducted by the captain and/or a member of the 
scientific crew before (within 1 nautical mile (nm) and 15 minutes 
prior to deploying gear), during, and after haul back.
    (2) Survey gear will be deployed as soon as possible once the 
vessel arrives on station.
    (3) Dominion Energy and/or its cooperating institutions, contracted 
vessels, or commercially-hired captains must implement the following 
``move-on'' rule: If marine mammals are sighted within 1 nm of the 
planned location and 15 minutes before gear deployment, Dominion Energy 
and/or its cooperating institutions, contracted vessels, or 
commercially-hired captains, as appropriate, must move the vessel away 
from the marine mammal to a different section of the sampling area. If, 
after moving on, marine mammals are still visible from the vessel, 
Dominion Energy and/or its cooperating institutions, contracted 
vessels, or commercially-hired captains must move again or skip the 
station.
    (4) If a marine mammal is deemed to be at risk of interaction after 
the gear is set, all gear must be immediately removed from the water.
    (5) Dominion Energy must maintain visual monitoring effort during 
the entire period of time that gear is in the water (i.e., throughout 
gear deployment, fishing, and retrieval).
    (6) All fisheries monitoring gear must be fully cleaned and 
repaired (if damaged) before each use.
    (7) All lost gear must be reported to NOAA Greater Atlantic 
Regional Fisheries Office Protected Resources Division 
([email protected]) within 24 hours of the documented 
time of missing or lost gear. This report must include information on 
any markings on the gear and any efforts undertaken or planned to 
recover the gear. All reasonable efforts, that do not compromise human 
safety, must be undertaken to recover gear.
    (8) Dominion Energy must implement measures within the Atlantic 
Large Whale Take Reduction Plan at 50 CFR 229.32.


Sec.  217.295  Requirements for monitoring and reporting.

    (a) Protected species observer (PSO) and passive acoustic 
monitoring (PAM) operator qualifications. Dominion Energy must 
implement the following measures applicable to PSOs and PAM operators:
    (1) Dominion Energy must use independent, dedicated, qualified 
PSOs, meaning that the PSOs must be employed by a third-party observer 
provider, must have no tasks other than to conduct observational 
effort, collect data, and communicate with and instruct relevant vessel 
crew with regard to the presence of protected species and mitigation 
requirements;
    (2) PSOs must successfully complete relevant training, including 
completion of all required coursework and passing a written and/or oral 
examination developed for the training;
    (3) PSOs must have successfully attained a bachelor's degree from 
an accredited college or university with a major in one of the natural 
sciences, a minimum of 30 semester hours or equivalent in the 
biological sciences, and at least one undergraduate course in math or 
statistics. The educational requirements may be waived if the PSO has 
acquired the relevant skills through alternate experience. Requests for 
such a waiver shall be submitted to NMFS and must include written 
justification. Alternate experience that may be considered includes, 
but is not limited to: Secondary education and/or experience comparable 
to PSO duties; previous work experience conducting academic, 
commercial, or government sponsored marine mammal surveys; or previous 
work experience as a PSO; the PSO should demonstrate good standing and 
consistently good performance of PSO duties;
    (4) PSOs must have visual acuity in both eyes (with correction of 
vision being permissible) sufficient enough to discern moving targets 
on the water's surface with the ability to estimate the target size and 
distance (binocular use is allowable); ability to conduct field 
observations and collect data according to the assigned protocols; 
sufficient training, orientation, or experience with the construction 
operation to provide for personal safety during observations; writing 
skills sufficient to document observations, including but not limited 
to, the number and species of marine mammals observed, the dates and 
times of when in-water construction activities were conducted, the 
dates and time when in-water construction activities were suspended to 
avoid potential incidental injury of marine mammals from construction 
noise within a defined shutdown zone, and marine mammal behavior; and 
the ability to communicate orally, by radio, or in-person, with project 
personnel to provide real-time information on marine mammals observed 
in the area, as necessary;
    (5) All PSOs must be approved by NMFS. Dominion Energy must submit 
PSO resumes for NMFS' review and approval at least 60 days prior to 
commencement of in-water construction activities requiring PSOs. 
Resumes must include dates of training and any prior NMFS approval, as 
well as dates and description of last experience, and must

[[Page 28773]]

be accompanied by information documenting successful completion of an 
acceptable training course. NMFS shall be allowed three weeks to 
approve PSOs from the time that the necessary information is received 
by NMFS, after which PSOs meeting the minimum requirements will 
automatically be considered approved;
    (6) All PSOs must be trained in marine mammal identification and 
behaviors and must be able to conduct field observations and collect 
data according to assigned protocols. Additionally, PSOs must have the 
ability to work with all required and relevant software and equipment 
necessary during observations;
    (7) At least one PSO on active duty for each activity (i.e., 
foundation installation, cable landfall activities, and HRG surveys) 
must be designated as the ``Lead PSO''. The Lead PSO must have a 
minimum of 90 days of at-sea experience working in an offshore 
environment and is required to have no more than eighteen months 
elapsed since the conclusion of their last at-sea experience;
    (8) PAM operators must complete specialized training for operating 
PAM systems and must demonstrate familiarity with the PAM system on 
which they must be working. PSOs may act as both acoustic operators and 
visual observers (but not simultaneously), so long as they demonstrate 
that their training and experience are sufficient to perform each task; 
and
    (9) PAM operators may additionally function as PSOs, assuming all 
qualifications and requirements in paragraphs (a)(1) through (7) of 
this section are met, but may only perform one role at any one time and 
must abide by the requirements specified for that role.
    (b) General PSO requirements. The following measures apply to PSOs 
during all project activities and must be implemented by Dominion 
Energy:
    (1) PSOs must monitor all clearance and shutdown zones prior to, 
during, and following pile driving, cable landfall construction 
activities, and during HRG surveys that use boomers, sparkers, and 
CHIRPs (with specific monitoring durations and needs described in 
paragraphs (c) through (e) of this section, respectively). PSOs must 
also monitor the Level B harassment zones and document any marine 
mammals observed within these zones, to the extent practicable. PSOs 
must ensure that there is appropriate visual coverage for the entire 
clearance and shutdown zones and as much of the Level B harassment zone 
as possible;
    (2) All PSOs must be located at the best vantage point(s) on the 
primary vessel, pile driving platform, or secondary platform, whichever 
is most appropriate to the activity occurring, in order to obtain 360 
degree visual coverage of the entire clearance and shutdown zones 
around the activity area, and as much of the Level B harassment zone as 
possible. PAM operators may be located on a vessel or remotely on-shore 
but must have the appropriate equipment (i.e., computer station 
equipped with a data collection software system (i.e., Mysticetus or 
similar system and acoustic data analysis software)) available wherever 
they are stationed;
    (3) During all visual observation periods, PSOs must use high 
magnification (25x) binoculars, standard handheld (7x) binoculars, and 
the naked eye to search continuously for marine mammals. During impact 
pile driving, at least one PSO on the primary pile driving vessel must 
be equipped with functional Big Eye binoculars (e.g., 25 x 150; 2.7 
view angle; individual ocular focus; height control). These must be 
pedestal mounted on the deck at the best vantage point that provides 
for optimal sea surface observation and PSO safety;
    (4) During periods of low visibility (e.g., darkness, rain, fog, 
poor weather conditions, etc.), PSOs must use alternative technology 
(i.e., infrared or thermal cameras) to monitor the clearance and 
shutdown zones;
    (5) PSOs must not exceed four consecutive watch hours on duty at 
any time, must have a two-hour (minimum) break between watches, and 
must not exceed a combined watch schedule of more than 12 hours in a 
24-hour period;
    (6) Any PSO has the authority to call for a delay or shutdown of 
project activities;
    (7) Any observations of marine mammals must be communicated to PSOs 
on all nearby project vessels during construction activities and 
surveys;
    (8) PSOs must remain in contact with the PAM operator currently on 
duty regarding any animal detection that would be approaching or found 
within the applicable zones no matter where the PAM operator is 
stationed (i.e., onshore or on a vessel);
    (9) During daylight hours when equipment is not operating, Dominion 
Energy must ensure that visual PSOs conduct, as rotation schedules 
allow, observations for comparison of sighting rates and behavior with 
and without use of the specified acoustic sources. Off-effort PSO 
monitoring must be reflected in the monthly PSO monitoring reports; and
    (10) Dominion Energy's personnel and PSOs are required to use 
available sources of information on North Atlantic right whale presence 
to aid in monitoring efforts. These include daily monitoring of the 
Right Whale Sightings Advisory System, consulting of the WhaleAlert 
app, and monitoring of the Coast Guard's VHF Channel 16 throughout the 
day to receive notifications of any sightings and information 
associated with any Dynamic Management Areas, to plan construction 
activities and vessel routes, if practicable, to minimize the potential 
for co-occurrence with North Atlantic right whales.
    (c) PSO and PAM operator requirements during WTG and OSS foundation 
installation. The following measures apply to PSOs and PAM operators 
during monopile and OSS foundation installation and must be implemented 
by Dominion Energy:
    (1) At least four PSOs must be actively observing marine mammals 
before, during, and after installation of foundation piles (i.e., 
monopiles and pin piles for jacket foundations). At least two PSOs must 
be stationed and observing on the pile driving vessel and at least two 
PSOs must be stationed on a secondary, PSO-dedicated vessel. 
Concurrently, at least one acoustic monitoring PSO (i.e., passive 
acoustic monitoring (PAM) operator) must be actively monitoring for 
marine mammals with PAM before, during, and after impact pile driving;
    (2) All on-duty visual PSOs must remain in contact with the on-duty 
PAM operator, who would monitor the PAM systems for acoustic detections 
of marine mammals in the area, regarding any animal detection that 
might be approaching or found within the applicable zones no matter 
where the PAM operator is stationed (i.e., onshore or on a vessel);
    (3) If PSOs cannot visually monitor the minimum visibility zone at 
all times using the equipment described in paragraphs (b)(3) and (4) of 
this section, pile driving operations must not commence or must 
shutdown if they are currently active;
    (4) All PSOs must begin monitoring 60 minutes prior to pile 
driving, during, and for 30 minutes after the activity. Pile driving 
must only commence when the minimum visibility zone is fully visible 
(e.g., not obscured by darkness, rain, fog, etc.) and the clearance 
zones are clear of marine mammals for at least 30 minutes, as 
determined by the Lead PSO, immediately prior to the initiation of pile 
driving. PAM operators must

[[Page 28774]]

assist the visual PSOs in monitoring by conducting PAM activities 60 
minutes prior to any pile driving, during, and after for 30 minutes for 
the appropriate size PAM clearance zone (dependent on season). The 
entire minimum visibility zone must be clear for at least 30 minutes, 
with no marine mammal detections within the visual or PAM clearance 
zones prior to the start of pile driving;
    (5) For North Atlantic right whales, any visual or acoustic 
detection must trigger a delay to the commencement of pile driving. In 
the event that a large whale is sighted or acoustically detected that 
cannot be confirmed by species, it must be treated as if it were a 
North Atlantic right whale;
    (6) Dominion Energy must conduct PAM for at least 24 hours 
immediately prior to pile driving activities;
    (7) During use of any real-time PAM system, at least one PAM 
operator must be designated to monitor each system by viewing data or 
data products that would be streamed in real-time or in near real-time 
to a computer workstation and monitor;
    (8) Dominion Energy must use a minimum of one PAM operator to 
actively monitor for marine mammals before, during, and after pile 
driving activities. The PAM operator must assist visual PSOs in 
ensuring full coverage of the clearance and shutdown zones. The PAM 
operator must inform the Lead PSO(s) on duty of animal detections 
approaching or within applicable ranges of interest to the pile driving 
activity via the data collection software system (i.e., Mysticetus or 
similar system) who will be responsible for requesting that the 
designated crewmember implement the necessary mitigation procedures 
(i.e., delay or shutdown);
    (9) PAM operators must be on watch for a maximum of four 
consecutive hours, followed by a break of at least two hours between 
watches, and may not exceed a combined watch schedule of more than 12 
hours in a single 24-hour period;
    (10) Dominion Energy must prepare and submit a Pile Driving and 
Marine Mammal Monitoring Plan to NMFS for review and approval at least 
180 days before the start of any pile driving. The plan must include 
final pile driving project design (e.g., number and type of piles, 
hammer type, noise abatement systems, anticipated start date, etc.) and 
all information related to PAM PSO monitoring protocols for pile-
driving and visual PSO protocols for all activities; and
    (11) A Passive Acoustic Monitoring (PAM) Plan must be submitted to 
NMFS for review and approval at least 180 days prior to the planned 
start of WTG or OSS installation. The authorization to take marine 
mammals would be contingent upon NMFS' approval of the PAM Plan.
    (d) PSO requirements during cable landfall construction. The 
following measures apply to PSOs during pile driving associated with 
cable landfall construction activities and must be implemented by 
Dominion Energy:
    (1) At least two PSOs must be on active duty during all activities 
related to the installation and removal of cofferdams, goal posts, and 
casing pipes;
    (2) The PSOs must be located at the best vantage points on the pile 
driving platform or secondary platform in the immediate vicinity of the 
pile driving; and
    (3) PSOs must monitor the clearance zone for the presence of marine 
mammals for 30 minutes before, throughout the installation of the sheet 
piles and casing pipes, and for 30 minutes after all pile driving 
activities have ceased. Pile driving must only commence when visual 
clearance zones are fully visible (e.g., not obscured by darkness, 
rain, fog, etc.) and clear of marine mammals, as determined by the Lead 
PSO, for at least 30 minutes immediately prior to initiation of impact 
or vibratory pile driving.
    (e) PSO requirements during HRG surveys. The following measures 
apply to PSOs during HRG surveys using SBPs and must be implemented by 
Dominion Energy:
    (1) Between four and six PSOs must be present on every 24-hour 
survey vessel and two to three PSOs must be present on every 12-hour 
survey vessel;
    (2) At least one PSO must be on active duty monitoring during HRG 
surveys conducted during daylight (i.e., from 30 minutes prior to civil 
sunrise through 30 minutes following civil sunset) and at least two 
PSOs must be on activity duty monitoring during HRG surveys conducted 
at night;
    (3) PSOs on HRG vessels must begin monitoring 30 minutes prior to 
activating SBPs during the use of these acoustic sources, and for 30 
minutes after use of these acoustic sources has ceased;
    (4) During daylight hours when survey equipment is not operating, 
Dominion Energy must ensure that visual PSOs conduct, as rotation 
schedules allow, observations for comparison of sighting rates and 
behavior with and without use of the specified acoustic sources. Off-
effort PSO monitoring must be reflected in the monthly PSO monitoring 
reports; and
    (5) Any acoustic monitoring would complement visual monitoring 
efforts and would cover an area of at least the Level B harassment zone 
around each acoustic source.
    (f) Reporting. Dominion Energy must comply with the following 
reporting measures:
    (1) Prior to initiation of project activities, Dominion Energy must 
demonstrate in a report submitted to NMFS Office of Protected Resources 
that all required training for Dominion Energy personnel (including the 
vessel crews, vessel captains, PSOs, and PAM operators) has been 
completed.
    (2) Dominion Energy must use a standardized reporting system during 
the effective period of this subpart and LOA. All data collected 
related to the CVOW-C project must be recorded using industry-standard 
softwares (e.g., Mysticetus or a similar software) that is installed on 
field laptops and/or tablets. Dominion Energy must submit weekly 
(during foundation installation only), monthly, and annual reports as 
described in paragraphs (f)(5) through (8) of this section. For all 
monitoring efforts and marine mammal sightings, the following 
information must be collected and made available to NMFS:
    (i) Date and time that monitored activity begins or ends;
    (ii) Construction activities occurring during each observation 
period;
    (iii) Watch status (i.e., sighting made by PSO on/off effort, 
opportunistic, crew, alternate vessel/platform);
    (iv) PSO who sighted the animal;
    (v) Time of sighting;
    (vi) Weather parameters (e.g., wind speed, percent cloud cover, 
visibility);
    (vii) Water conditions (e.g., sea state, tide state, water depth);
    (viii) All marine mammal sightings, regardless of distance from the 
construction activity;
    (ix) Species (or lowest possible taxonomic level possible);
    (x) Pace of the animal(s);
    (xi) Estimated number of animals (minimum/maximum/high/low/best);
    (xii) Estimated number of animals by cohort (e.g., adults, 
yearlings, juveniles, calves, group composition, etc.);
    (xiii) Description (i.e., as many distinguishing features as 
possible of each individual seen, including length, shape, color, 
pattern, scars or markings, shape and size of dorsal fin, shape of 
head, and blow characteristics);
    (xiv) Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling) and observed 
changes in behavior, including an assessment of behavioral responses 
thought to have resulted from the specific activity;
    (xv) Animal's closest distance and bearing from the pile being 
driven or

[[Page 28775]]

specified HRG equipment and estimated time entered or spent within the 
Level A harassment and/or Level B harassment zones;
    (xvi) Activity at time of sighting (e.g., vibratory installation/
removal, impact pile driving, construction survey), use of any noise 
attenuation device(s), and specific phase of activity (e.g., ramp-up of 
HRG equipment, HRG acoustic source on/off, soft-start for pile driving, 
active pile driving, etc.);
    (xvii) Marine mammal occurrence in Level A harassment or Level B 
harassment zones;
    (xviii) Description of any mitigation-related action implemented, 
or mitigation-related actions called for but not implemented, in 
response to the sighting (e.g., delay, shutdown, etc.) and time and 
location of the action; and
    (xix) Other human activity in the area.
    (3) If a marine mammal is acoustically detected during PAM 
monitoring, the following information must be recorded and reported to 
NMFS:
    (i) Location of hydrophone (latitude & longitude; in Decimal 
Degrees) and site name;
    (ii) Bottom depth and depth of recording unit (in meters);
    (iii) Recorder (model & manufacturer) and platform type (i.e., 
bottom-mounted, electric glider, etc.), and instrument ID of the 
hydrophone and recording platform (if applicable);
    (iv) Time zone for sound files and recorded date/times in data and 
metadata (in relation to Universal Coordinated Time (UTC); i.e., 
Eastern Standard Time (EST) time zone is UTC-5);
    (v) Duration of recordings (start/end dates and times; in 
International Organization for Standardization (ISO) 8601 format, yyyy-
mm-ddTHH:MM:SS.sssZ);
    (vi) Deployment/retrieval dates and times (in ISO 8601 format);
    (vii) Recording schedule (must be continuous);
    (viii) Hydrophone and recorder sensitivity (in dB re. 1 microPascal 
([mu]Pa));
    (ix) Calibration curve for each recorder;
    (x) Bandwidth/sampling rate (in Hz);
    (xi) Sample bit-rate of recordings; and,
    (xii) Detection range of equipment for relevant frequency bands (in 
meters).
    (4) Information required for each detection, the following 
information must be noted:
    (i) Species identification (if possible);
    (ii) Call type and number of calls (if known);
    (iii) Temporal aspects of vocalization (date, time, duration, etc.; 
date times in ISO 8601 format);
    (iv) Confidence of detection (detected, or possibly detected);
    (v) Comparison with any concurrent visual sightings;
    (vi) Location and/or directionality of call (if determined) 
relative to acoustic recorder or construction activities;
    (vii) Location of recorder and construction activities at time of 
call;
    (viii) Name and version of detection or sound analysis software 
used, with protocol reference;
    (ix) Minimum and maximum frequencies viewed/monitored/used in 
detection (in Hz); and
    (x) Name of PAM operator(s) on duty.
    (5) Dominion Energy must compile and submit weekly reports to NMFS 
Office of Protected Resources that document the daily start and stop of 
all pile driving and HRG survey, the start and stop of associated 
observation periods by PSOs, details on the deployment of PSOs, a 
record of all detections of marine mammals (acoustic and visual), any 
mitigation actions (or if mitigation actions could not be taken, 
provide reasons why), and details on the noise attenuation system(s) 
used and its performance. Weekly reports are due on Wednesday for the 
previous week (Sunday-Saturday) and must include the information 
required under this section. The weekly report must also identify which 
turbines become operational and when (a map must be provided). Once all 
foundation pile installation is completed, weekly reports are no longer 
required.
    (6) Dominion Energy must compile and submit monthly reports to NMFS 
(at [email protected] and [email protected]) that 
include a summary of all information in the weekly reports, including 
project activities carried out in the previous month, vessel transits 
(number, type of vessel, and route), number of piles installed, all 
detections of marine mammals, and any mitigative action taken. Monthly 
reports are due on the 15th of the month for the previous month. The 
monthly report must also identify which turbines become operational and 
when (a map must be provided). Once foundation installation is 
complete, monthly reports are no longer required.
    (7) Dominion Energy must submit a draft annual report to NMFS 
Office of Protected Resources no later than 90 days following the end 
of a given calendar year. Dominion Energy must provide a final report 
within 30 days following resolution of comments on the draft report. 
The draft and final reports must detail the following information:
    (i) The total number of marine mammals of each species/stock 
detected and how many were within the designated Level A harassment and 
Level B harassment zones with comparison to authorized take of marine 
mammals for the associated activity type;
    (ii) Marine mammal detections and behavioral observations before, 
during, and after each activity;
    (iii) What mitigation measures were implemented (i.e., number of 
shutdowns or clearance zone delays, etc.) or, if no mitigative actions 
was taken, why not;
    (iv) Operational details (i.e., days of impact and vibratory pile 
driving, days/amount of HRG survey effort, etc.);
    (v) Any PAM systems used;
    (vi) The results, effectiveness, and which noise attenuation 
systems were used during relevant activities (i.e., impact pile 
driving);
    (vii) Summarized information related to situational reporting; and
    (viii) Any other important information relevant to the CVOW-C 
project, including additional information that may be identified 
through the adaptive management process.
    (ix) The final annual report must be prepared and submitted within 
30 calendar days following the receipt of any comments from NMFS on the 
draft report. If no comments are received from NMFS within 60 calendar 
days of NMFS' receipt of the draft report, the report must be 
considered final.
    (8) Dominion Energy must submit its draft final report to NMFS 
Office of Protected Resources on all visual and acoustic monitoring 
conducted under the LOA within 90 calendar days of the completion of 
activities occurring under the LOA. A final report must be prepared and 
submitted within 30 calendar days following receipt of any NMFS 
comments on the draft report. If no comments are received from NMFS 
within 30 calendar days of NMFS' receipt of the draft report, the 
report shall be considered final.
    (9) Dominion Energy must submit a SFV plan at least 180 days prior 
to the planned start of vibratory and/or impact pile driving. The plan 
must describe how Dominion Energy would ensure that the first three WTG 
monopile and OSS jacket (using pin piles) foundation installation sites 
selected for SFV are representative of the rest of the monopile and pin 
pile installation sites. In the case that these sites/scenarios are not 
determined to be representative of all other monopile/pin pile 
installation sites, Dominion Energy must include information on how 
additional sites/scenarios would be selected for SFV. The plan must 
also include methodology for collecting, analyzing,

[[Page 28776]]

and preparing SFV data for submission to NMFS. The plan must describe 
how the effectiveness of the sound attenuation methodology would be 
evaluated based on the results. Dominion Energy must also provide, as 
soon as they are available but no later than 48 hours after each 
installation, the initial results of the SFV measurements to NMFS in an 
interim report after each monopile for the first three piles and after 
each OSS jacket foundation using pin piles are installed.
    (i) The SFV plan must also include how operational noise would be 
monitored. Dominion Energy must estimate source levels (at 10 m from 
the operating foundation) based on received levels measured at 50 m, 
100 m, and 250 m from the pile foundation. These data must be used to 
identify estimated transmission loss rates. Operational parameters 
(e.g., direct drive/gearbox information, turbine rotation rate) as well 
as sea state conditions and information on nearby anthropogenic 
activities (e.g., vessels transiting or operating in the area) must be 
reported.
    (ii) Dominion Energy must provide the initial results of the SFV 
measurements to NMFS in an interim report after each monopile and pin 
pile foundation installation for the first three monopiles piles and/or 
two full OSS foundations (consisting of 8 total pin piles) as soon as 
they are available, but no later than 48 hours after each installation. 
Dominion Energy must also provide interim reports on any subsequent SFV 
on foundation piles within 48 hours. The interim report must include 
hammer energies used during pile driving, peak sound pressure level 
(SPLpk) and median, mean, maximum, and minimum root-mean-
square sound pressure level that contains 90 percent of the acoustic 
energy (SPLrms) and single strike sound exposure level 
(SELss).
    (iii) The final results of SFV of foundation installations must be 
submitted as soon as possible, but no later than within 90 days 
following completion of pile driving of monopiles and pin piles. The 
final report must include, at minimum, the following:
    (A) Peak sound pressure level (SPLpk), root-mean-square 
sound pressure level that contains 90 percent of the acoustic energy 
(SPLrms), single strike sound exposure level 
(SELss), integration time for SPLrms, spectrum, 
and 24-hour cumulative SEL extrapolated from measurements at specified 
distances (e.g., 750 m);
    (B) All these levels must be reported in the form of:
    (1) Median;
    (2) Mean;
    (3) Maximum; and
    (4) Minimum;
    (C) The SEL and SPL power spectral density and one-third octave 
band levels (usually calculated as decidecade band levels) at the 
receiver locations should be reported;
    (D) The sound levels reported must be in median and linear average 
(i.e., average in linear space), and in dB;
    (E) A description of depth and sediment type, as documented in the 
Construction and Operation Plan (COP), at the recording and pile 
driving locations;
    (F) Hammer energies required for pile installation and the number 
of strikes per pile;
    (G) Hydrophone equipment and methods (i.e., recording device, 
bandwidth/sampling rate, distance from the pile where recordings were 
made; depth of recording device(s));
    (H) Description of the SFV PAM hardware and software, including 
software version used, calibration data, bandwidth capability and 
sensitivity of hydrophone(s), any filters used in hardware or software, 
any limitations with the equipment, and other relevant information;
    (I) Local environmental conditions, such as wind speed, 
transmission loss data collected on-site (or the sound velocity 
profile), baseline pre- and post-activity ambient sound levels 
(broadband and/or within frequencies of concern);
    (J) Spatial configuration of the noise attenuation device(s) 
relative to the pile;
    (K) The extents of the Level A harassment and Level B harassment 
zones; and
    (L) A description of the noise abatement system and operational 
parameters (e.g., bubble flow rate, distance deployed from the pile, 
etc.) and any action taken to adjust the noise abatement system.
    (10) Dominion Energy must submit situational reports if the 
following circumstances occur:
    (i) If a North Atlantic right whale is observed at any time by PSOs 
or personnel on or in the vicinity of any project vessel, or during 
vessel transit, Dominion Energy must immediately report sighting 
information to the NMFS North Atlantic Right Whale Sighting Advisory 
System (866) 755-6622, through the WhaleAlert app (https://www.whalealert.org/), and to the U.S. Coast Guard via channel 16, as 
soon as feasible but no longer than 24 hours after the sighting. 
Information reported must include, at a minimum: time of sighting, 
location, and number of North Atlantic right whales observed.
    (ii) When an observation of a large whale occurs during vessel 
transit, the following information must be recorded and reported to 
NMFS:
    (A) Time, date, and location (latitude/longitude; in Decimal 
Degrees);
    (B) The vessel's activity, heading, and speed;
    (C) Sea state, water depth, and visibility;
    (D) Marine mammal identification to the best of the observer's 
ability (e.g., North Atlantic right whale, whale, dolphin, seal);
    (E) Initial distance and bearing to marine mammal from vessel and 
closest point of approach; and
    (F) Any avoidance measures taken in response to the marine mammal 
sighting.
    (iii) If a North Atlantic right whale is detected via PAM, the 
date, time, location (i.e., latitude and longitude of recorder) of the 
detection as well as the recording platform that had the detection must 
be reported to [email protected] as soon as feasible, but no 
longer than 24 hours after the detection. Full detection data and 
metadata must be submitted monthly on the 15th of every month for the 
previous month via the webform on the NMFS North Atlantic right whale 
Passive Acoustic Reporting System website at https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-system-templates.
    (iv) In the event that the personnel involved in the activities 
defined in Sec.  217.290(a) discover a stranded, entangled, injured, or 
dead marine mammal, Dominion Energy must immediately report the 
observation to the NMFS Office of Protected Resources (OPR), the NMFS 
Greater Atlantic Stranding Coordinator for the New England/Mid-Atlantic 
area (866-755-6622), and the U.S. Coast Guard within 24 hours. If the 
injury or death was caused by a project activity, Dominion Energy must 
immediately cease all activities until NMFS OPR is able to review the 
circumstances of the incident and determine what, if any, additional 
measures are appropriate to ensure compliance with the terms of the 
LOA. NMFS may impose additional measures to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. Dominion Energy may 
not resume their activities until notified by NMFS. The report must 
include the following information:
    (A) Time, date, and location (latitude/longitude; in Decimal 
Degrees) of the first discovery (and updated location information if 
known and applicable);

[[Page 28777]]

    (B) Species identification (if known) or description of the 
animal(s) involved;
    (C) Condition of the animal(s) (including carcass condition if the 
animal is dead);
    (D) Observed behaviors of the animal(s), if alive;
    (E) If available, photographs or video footage of the animal(s); 
and
    (F) General circumstances under which the animal was discovered.
    (v) In the event of a vessel strike of a marine mammal by any 
vessel associated with the CVOW-C project, Dominion Energy must 
immediately report the strike incident to the NMFS OPR and the NMFS 
Greater Atlantic Regional Fisheries Office (GARFO) within and no later 
than 24 hours. Dominion Energy must immediately cease all on-water 
activities until NMFS OPR is able to review the circumstances of the 
incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the LOA. NMFS may 
impose additional measures to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. Dominion Energy may not 
resume their activities until notified by NMFS. The report must include 
the following information:
    (A) Time, date, and location (latitude/longitude; in Decimal 
Degrees) of the incident;
    (B) Species identification (if known) or description of the 
animal(s) involved;
    (C) Vessel's speed leading up to and during the incident;
    (D) Vessel's course/heading and what operations were being 
conducted (if applicable);
    (E) Status of all sound sources in use;
    (F) Description of avoidance measures/requirements that were in 
place at the time of the strike and what additional measures were 
taken, if any, to avoid strike;
    (G) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, visibility) immediately preceding the 
strike;
    (H) Estimated size and length of animal that was struck;
    (I) Description of the behavior of the marine mammal immediately 
preceding and following the strike;
    (J) If available, description of the presence and behavior of any 
other marine mammals immediately preceding the strike;
    (K) Estimated fate of the animal (e.g., dead, injured but alive, 
injured and moving, blood or tissue observed in the water, status 
unknown, disappeared); and
    (L) To the extent practicable, photographs or video footage of the 
animal(s).


Sec.  217.296  Letter of Authorization.

    (a) To incidentally take marine mammals pursuant to this subpart, 
Dominion Energy must apply for and obtain an LOA.
    (b) An LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed February 4, 2029, the expiration date of 
this subpart.
    (c) In the event of projected changes to the activity or to 
mitigation and monitoring measures required by an LOA, Dominion Energy 
must apply for and obtain a modification of the LOA as described in 
Sec.  217.297.
    (d) The LOA must set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, its habitat, and on the availability of the 
species for subsistence uses; and
    (3) Requirements for monitoring and reporting.
    (e) Issuance of the LOA must be based on a determination that the 
level of taking must be consistent with the findings made for the total 
taking allowable under the regulations of this subpart.
    (f) Notice of issuance or denial of an LOA must be published in the 
Federal Register within 30 days of a determination.


Sec.  217.297  Modifications of Letter of Authorization.

    (a) An LOA issued under Sec. Sec.  217.292 and 217.296 or this 
section for the activity identified in Sec.  217.290(a) shall be 
modified upon request by the applicant, provided that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for this subpart (excluding changes made 
pursuant to the adaptive management provision in paragraph (c)(1) of 
this section); and
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA under this subpart were 
implemented.
    (b) For a LOA modification request by the applicant that include 
changes to the activity or the mitigation, monitoring, or reporting 
(excluding changes made pursuant to the adaptive management provision 
in paragraph (c)(1) of this section) that do not change the findings 
made for the regulations in this subpart or result in no more than a 
minor change in the total estimated number of takes (or distribution by 
species or years), NMFS may publish a notice of proposed LOA in the 
Federal Register, including the associated analysis of the change, and 
solicit public comment before issuing the LOA.
    (c) An LOA issued under Sec. Sec.  217.292 and 217.296 or this 
section for the activities identified in Sec.  217.290(a) may be 
modified by NMFS under the following circumstances:
    (1) Through adaptive management, NMFS may modify (including 
augment) the existing mitigation, monitoring, or reporting measures 
(after consulting with Dominion Energy regarding the practicability of 
the modifications), if doing so creates a reasonable likelihood of more 
effectively accomplishing the goals of the mitigation and monitoring.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in an LOA 
are:
    (A) Results from Dominion Energy's monitoring from the previous 
year(s);
    (B) Results from other marine mammals and/or sound research or 
studies;
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent, or number not authorized by the regulations in 
this subpart or subsequent LOA; and
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
shall publish a notice of proposed LOA in the Federal Register and 
solicit public comment.
    (2) If NMFS determines that an emergency exists that poses a 
significant risk to the well-being of the species or stocks of marine 
mammals specified in the LOA issued pursuant to Sec. Sec.  217.292 and 
217.296 or this section, an LOA may be modified without prior notice or 
opportunity for public comment. Notice would be published in the 
Federal Register within thirty days of the action.


Sec. Sec.  217.298-217.299  [Reserved]

[FR Doc. 2023-08924 Filed 5-3-23; 8:45 am]
 BILLING CODE 3510-22-P