Ocean Dumping; De-designation of Ocean Dredged Material Disposal Sites and Designation of New Sites, 10041-10057 [05-4002]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 70, Number 40 (Wednesday, March 2, 2005)]
[Rules and Regulations]
[Pages 10041-10057]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-4002]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 228

[FRL-7877-9]


Ocean Dumping; De-designation of Ocean Dredged Material Disposal 
Sites and Designation of New Sites

AGENCY: Environmental Protection Agency.

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is finalizing its 
proposal to de-designate four existing ocean dredged material disposal 
sites located off of the mouth of the Columbia River near the states of 
Oregon and Washington and to designate two new sites, the Shallow Water 
site (SWS) and the Deep Water site (DWS). The new sites are needed for 
long-term use by authorized Columbia River navigation projects and may 
be available for use by others meeting the criteria for ocean disposal 
of dredged material. EPA published its proposal to designate the two 
new ocean disposal sites and to de-designate the four existing ocean 
disposal sites in the Federal Register on March 11, 2003 (68 FR 11488). 
The de-designation of existing sites is necessary to discontinue their 
use where the impact of disposal has resulted in changed and adverse 
site conditions. The newly designated sites are necessary for current 
and future dredged material ocean disposal needs and will be subject to 
ongoing monitoring and management to ensure continued protection of the 
marine environment from adverse effects to the greatest extent 
practicable.

DATES: Effective Date: This final site designation and de-designation 
becomes effective on April 1, 2005.

ADDRESSES: The administrative record for this final action is available 
for inspection at the Region 10 Library, 10th Floor, 1200 Sixth Avenue, 
Seattle, Washington 98101. For access to the administrative record, 
contact the Region 10 Library Reference Desk at (206) 553-1289, between 
9 a.m. and 4 p.m., Monday through Friday, excluding legal holidays, for 
an appointment. The EPA public information regulations (40 CFR part 2) 
provide that a reasonable fee may be charged for copying.

FOR FURTHER INFORMATION CONTACT: John Malek, Ocean Dumping Coordinator, 
U.S. Environmental Protection Agency, Region 10 (ETPA-083), 1200 Sixth 
Avenue, Seattle, WA 98101-1128, telephone (206) 553-1286, e-mail: 
malek.john@epa.gov.

SUPPLEMENTARY INFORMATION: 

1. Regulated Entities

    Entities potentially affected by this action include those who seek 
or might seek permits or approval by EPA to dispose of dredged material 
into ocean waters pursuant to the Marine Protection, Research, and 
Sanctuaries Act, as amended, 33 U.S.C. 1401 to 1445, (MPRSA). The 
action would be relevant to entities, including the U.S. Army Corps of 
Engineers (Corps), seeking to dispose of dredged materials in ocean 
waters off the mouth of the Columbia River near the states of Oregon 
and Washington. Potentially affected categories and entities include:

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                                                                              Examples of potentially regulated
                                  Category                                                 entities
----------------------------------------------------------------------------------------------------------------
Federal Government.........................................................  U.S. Army Corps of Engineers Civil
                                                                              Works Projects, Regulatory
                                                                              Program, Other Federal Agencies.
Industry and General Public................................................  Port Authorities, Marinas and
                                                                              Harbors, Shipyards and Marine
                                                                              Repair Facilities, Berth Owners.
State, local and tribal governments........................................  Governments owning and/or
                                                                              responsible for ports, harbors,
                                                                              and/or berths, Government agencies
                                                                              requiring disposal of dredged
                                                                              material associated with public
                                                                              works projects.
----------------------------------------------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be affected by this 
action. For any questions regarding the applicability of this action to 
a particular entity, please consult the person listed in the section of 
this action titled FOR FURTHER INFORMATION CONTACT.

2. Background

    The EPA published a proposal in the Federal Register on March 11, 
2003, (68 FR 11488), to de-designate four ocean dredged material 
disposal sites and to designate two new ocean dredged material disposal 
sites under Section 102(c) of the MPRSA and its implementing 
regulations at 40 CFR subchapter H. Under the MPRSA, the Administrator 
of EPA has the authority, which is delegated to the Regional 
Administrator of the Region in which the sites are located, to 
designate sites where ocean disposal may be permitted. The sites that 
are designated in today's action and the sites that are de-designated 
in today's action are located near the mouth of the Columbia River, 
within Region 10. Figure 1 displays the de-designated sites. Figure 2 
displays the newly designated sites. [Figures 1 and 2 are attached at 
the end of this document.]
    The proposed designations and de-designations were accompanied by a 
joint EPA and Corps ``Integrated Feasibility Report and Environmental 
Impact Statement for Channel Improvements,'' August 1999 (1999 IFR/

[[Page 10042]]

EIS), and a ``Supplemental Integrated Feasibility Report and 
Environmental Impact Statement,'' January 28, 2003 (SEIS), consistent 
with EPA's voluntary Environmental Impact Statement (EIS) policy (63 FR 
58054, October 29, 1998). These documents incorporated a Biological 
Assessment as submitted to the National Marine Fisheries Service 
(NMFS), now known as NOAA Fisheries, pursuant to Section 7 of the 
Endangered Species Act (ESA) (16 U.S.C. 1536). The proposal was also 
accompanied by an Essential Fish Habitat (EFH) evaluation jointly 
prepared by EPA and the Corps and submitted to NOAA Fisheries pursuant 
to the Magnuson-Stevens Fishery Conservation and Management Act, 16 
U.S.C. 1801, et seq., as amended (MSA). A draft Site Management and 
Monitoring Plan (SMMP) was prepared as required by section 102(c)(3) of 
the MPRSA and was made available for review and comment at the time EPA 
published the proposal in the Federal Register. The draft SMMP has been 
finalized. The ``Public Comment'' section of this action discusses 
changes made to this document. Copies of the Final SMMP are available 
from EPA and the Corps Portland District. To obtain copies contact the 
individual listed in the section of this action titled FOR FURTHER 
INFORMATION CONTACT.
    The sites proposed for de-designation were sites A, B, E and F as 
currently codified at 40 CFR 228.15(n)(6), (7), (8) and (9). Sites A, B 
and F, designated in 1986, experienced adverse mounding after many 
years of disposal use. In 1993 and again in 1997, EPA and the Corps 
temporarily expanded the sites and changed the disposal patterns. These 
efforts were intended to provide short-term capacity while studies were 
conducted by the EPA and Corps to develop a long-term solution. Formal 
designation of the expanded sites was considered but found not to be a 
solution for the long term because of increased mounding at the sites 
and the use of these sites was curtailed. The past disposal activities 
at these sites place them in Impact Category II in EPA's evaluation of 
disposal impacts. See 40 CFR 228.10(c)(2). These sites are de-
designated in today's action. With respect to Site E, disposal impacts 
at the site indicate Site E is under-sized for the dispersive 
conditions experienced at the site. Site E is de-designated in today's 
action based on this assessment.
    Two sites were proposed for designation in EPA's proposed action. 
These sites are the Shallow Water Site (SWS), a near-shore dispersive 
site, and the Deep Water Site (DWS), a deep-water, off-shore, non-
dispersive site. These sites were assessed against the statutory and 
regulatory criteria for ocean site designations. EPA's evaluation of 
the SWS and DWS against the designation criteria was presented in the 
1999 IFR/EIS, Appendix H, and in the SEIS. Both sites meet the general 
criteria for designation.
    The proposed SWS and the DWS were also assessed against the 
specific criteria for ocean site designations at 40 CFR 228.6. The 
specific criteria include: geographical position; location relative to 
breeding, spawning, nursery, feeding or passage areas for adult and 
juvenile phases for living resources; location relative to beaches and 
other amenity areas; types and quantities of waste to be disposed of 
and proposed methods of release, feasibility of surveillance and 
monitoring; dispersal, horizontal transport and vertical mixing 
characteristics of the area to be designated including prevailing 
current direction and velocity; existence and effects of current and 
previous discharges and dumping in the area; interference with 
shipping, fishing, recreation, mineral extraction, desalination, fish 
and shellfish culture, areas of special scientific importance, and 
other legitimate uses of the ocean; existing water quality and ecology 
of the site as determined by available data or by trend assessment or 
baseline survey; potentiality for the development or recruitment of 
nuisance species in the disposal site; and proximity to significant 
natural or cultural features of historical significance. EPA's 
consideration of the specific criteria for site selection was presented 
in the 1999 IFR/EIS, Appendix H, and in the SEIS. As considered against 
the specific criteria, the SWS and the DWS mitigate adverse impact on 
the environment to the greatest extent practicable.
    Today's final action is also supported by several reports that were 
finalized during or after publication of the proposed designations and 
de-designations. These include: ``Environmental Studies at Proposed 
Ocean Disposal Sites off the Mouth of the Columbia River,'' prepared by 
MEC Analytical Systems, Inc. and Science Applications International 
Corporation (SAIC), June 2003 (Biological Baseline Study); ``Mouth of 
the Columbia River Shallow Water Ocean Dredged Material Disposal Site 
Supplemental Evaluation of Optimized Site Utilization and Assessment of 
Potential Wave-Related Impacts,'' prepared by the Corps, March 2003 
(MCR Optimized Site Utilization Report); ``Estimated Entrainment of 
Dungeness Crab During Maintenance Dredging of the Mouth of the Columbia 
River, Summer 2002,'' prepared by Pearson and Skalski, March 2003 (Crab 
Entrainment Study); and ``Comparison of the Sampling Efficiency of 
Three Benthic Trawls At the Deep Water Site off the Mouth of the 
Columbia River,'' (Trawl Comparison Study) prepared by MEC Analytical 
Systems, Inc., Weston Solutions, Inc. and Science Applications 
International Corporation, April 2004. EPA considered the data used in 
the preparation of these reports. The data and the reports themselves 
confirm EPA's conclusions at the time of the proposal concerning the 
biology and capacity at the sites proposed.
    The Ocean Dumping Regulations at 40 CFR 228.11 govern the 
withdrawal of designated sites from use by promulgation of an amendment 
to the disposal site designations. EPA may withdraw designated sites 
from use based on an evaluation of disposal impacts or changed 
circumstances concerning the use of the sites.
    EPA finds that the de-designation of sites A, B, and F is necessary 
based on changed circumstances at the sites. Continued disposal at the 
sites could result in further formation of mounds that would eventually 
contribute to adverse wave conditions and resultant navigation 
concerns. The past activities at sites A, B and F placed these sites in 
Category II impacts (40 CFR 228.10(c)(2)). The sites cannot be modified 
or expanded without causing conflicts with marine traffic and in their 
current state they are subject to adverse wave conditions.
    The de-designation of site E is based on the need to modify and 
reconfigure the site. Reconfiguration of the site will allow dredged 
material disposed at the site to naturally disperse into the littoral 
zone during the dredging season without the creation of mounding 
conditions that could contribute to adverse wave conditions at the 
site.
    The proposed action (68 FR 11488) provided an analysis of the EPA's 
compliance with the site designation criteria of Section 102 of the 
MPRSA and with 40 CFR part 228. This final action promulgates, without 
change from the proposal, the amendment of 40 CFR 228.15(n) to de-
designate sites A, B and F. The coordinates (North American Datum 1983; 
NAD 83) of the three EPA-designated sites which this final action de-
designates are as follows:

Site A

Corner Coordinates

46[deg]13'03'' N, 124[deg]06'17'' W.
46[deg]12'50'' N, 124[deg]05'55'' W.
46[deg]12'13'' N, 124[deg]06'43'' W.
46[deg]12'26'' N, 124[deg]07'05'' W.

[[Page 10043]]

Site B

Corner Coordinates

46[deg]14'37'' N, 124[deg]10'34'' W.
46[deg]13'53'' N, 124[deg]10'01'' W.
46[deg]13'43'' N, 124[deg]10'26'' W.
46[deg]14'28'' N, 124[deg]10'59'' W.

Site F

Corner Coordinates

46[deg]12'12'' N, 124[deg]09'00'' W.
46[deg]12'00'' N, 124[deg]08'42'' W.
46[deg]11'48'' N, 124[deg]09'00'' W.
46[deg]12'00'' N, 124[deg]09'18'' W.

    The coordinates (NAD 83) of Site E (original Site E) which this 
final action de-designates through reconfiguration are as follows:

Site E

Corner Coordinates

46[deg]15'43'' N, 124[deg]05'21'' W.
46[deg]15'36'' N, 124[deg]05'11'' W.
46[deg]15'11'' N, 124[deg]05'53'' W.
46[deg]15'18'' N, 124[deg]06'03'' W.

    This action finalizes the designation of the SWS without change 
from the proposal. The SWS incorporates the footprints of the original 
Site E and the Corps-selected 103 expanded Site E. It is configured so 
that the new site is large enough to allow for the temporary storage of 
placed material as it is naturally dispersed into the littoral zone 
during the disposal season avoiding the creation of conditions that 
could interfere with navigation safety. The coordinates for the newly 
designated sites utilize ``decimal seconds.'' The old coordinates just 
used ``seconds'' and were slightly less precise. The coordinates (NAD 
83) of the newly designated SWS, consisting of a disposal site with 
defined placement area and drop zone, are as follows:

Shallow Water Placement Area and Disposal Site

Corner Coordinates

46[deg]15'31.64 N, 124[deg]05'09.72 W.
46[deg]14'17.66 N, 124[deg]07'14.54 W.
46[deg]15'02.87 N, 124[deg]08'11.47 W.
46[deg]15'52.77 N, 124[deg]05'42.92 W.

Dimensions

3,100 to 5,600 feet wide by 11,500 feet long. Azimuth (long axis): 
229[deg]T, Depth 45 feet to 75 feet, No Buffer.

Shallow Water Drop Zone

Corner Coordinates

46[deg]15'35.36 N, 124[deg]05'15.55 W.
46[deg]14'31.07 N, 124[deg]07'03.25 W.
46[deg]14'58.83 N, 124[deg]07'36.89 W.
46[deg]15'42.38 N, 124[deg]05'26.65 W.

Dimensions

1,054 feet wide to 3,600 feet wide by 10,000. Azimuth (long axis): 
229[deg]T, Depth 45 feet to 75 feet.

    This action also finalizes the designation of the DWS without 
change from the proposal. The designation of this site is necessary to 
provide sufficient capacity for the disposal of dredged materials to 
meet current and anticipated future ocean disposal needs at the mouth 
of the Columbia River. The coordinates (NAD 83) of the newly designated 
DWS, consisting of a disposal site (including buffer and placement 
area), are as follows:

Deep Water Disposal Site (Including Buffer)

Corner Coordinates

46[deg]11'03.03 N, 124[deg]10'01.30 W.
46[deg]13'09.78 N, 124[deg]12'39.67 W.
46[deg]10'40.88 N, 124[deg]16'46.48 W.
46[deg]08'34.22 N, 124[deg]14'08.07 W.

Dimensions

17,000 feet wide by 23,000 feet long. Depth 190 feet to 300 feet, 
Buffer 3,000 feet wide.

Deep Water Placement Area

Corner Coordinates

46[deg]11'06.00 N, 124[deg]11'05.99 W.
46[deg]12'28.01 N, 124[deg]12'48.48 W.
46[deg]10'37.96 N, 124[deg]15'50.91 W.
46[deg]09'15.99 N, 124[deg]14'08.40 W.

Dimensions

11,000 feet wide by 17,000 feet long. Depth 190 feet to 290 feet.

    The de-designations are shown in Figure 1. The designations are 
shown in Figure 2.

3. Public Comments

    In the preamble to the proposed action, EPA requested that public 
comments be submitted by no later than April 25, 2003. EPA received 
approximately fifteen sets of written comments on the proposed action. 
While many of the comments expressed support for EPA's proposal, the 
greater number raised issues concerning the proposed designations and 
de-designations. In developing the final action, EPA reviewed and 
considered all the written comments. This final action addresses the 
most significant of the comments received and groups EPA's responses to 
similar significant comments together. EPA prepared a separate 
``Response to Comments'' to respond to every comment received and 
copies of the complete response to all comments may be obtained by 
contacting the individual listed in the section of this action titled 
FOR FURTHER INFORMATION CONTACT. The following discussion in this 
section summarizes and responds to the most significant comments 
received on the proposed action.
    Need for Ocean Dredged Material Disposal Sites under the MPRSA--One 
commenter stated that EPA must ``specifically find that there are no 
practicable improvements that will reduce the adverse impacts of the 
dredged materials on the total environment'' before designating an 
ocean dredged material disposal site. There is no requirement that EPA 
make this specific finding. Site designations are governed by the MPRSA 
and its implementing regulations. The general requirements for the 
designation of sites are as follows: ``The Administrator shall, in a 
manner consistent with the criteria established pursuant to subsection 
(a) of this section, designate sites or time periods for dumping. The 
Administrator shall designate sites or time periods for dumping that 
will mitigate adverse impact on the environment to the greatest extent 
practicable.'' 33 U.S.C. 1412(c)(1); MPRSA 102(c)(1). Sites are to be 
designated in a manner consistent with the criteria for permitting 
under the Act. The factors to be considered for site designation 
include the need for dumping; the effects of such dumping on human 
health and welfare, on fisheries resources and on marine ecosystems; 
the persistence and permanence of the effects of dumping; the volumes 
and concentrations of materials dumped; the appropriate locations for 
such dumping, including land-based alternatives; and the effect on 
alternate uses of oceans, and utilization wherever feasible of 
locations beyond the continental shelf. In assessing the need for ocean 
dredged material disposal sites, EPA focused on the need for ocean 
dumping and looked to factors such as relative environmental risks, and 
impact and cost for ocean dumping as compared to other feasible 
alternatives. EPA did not find feasible alternatives for the disposal 
of the millions of cubic yards of sediment dredged annually at the 
Mouth of the Columbia River. There was no practicable improvement in 
process technology for such sediments and there were no suitable and 
reliable estuarine, upland, flow-lane or other alternatives for near-
shore disposal or storage that did not present potentially greater 
adverse environmental impacts than ocean disposal.
    Zone of Siting Feasibility--One commenter questioned the 
justification for the non-feasibility of designating a

[[Page 10044]]

site off of the continental shelf based on a 4.5 mile operational limit 
of the Mouth of the Columbia River project. The MPRSA and its 
implementing regulations express a preference for designating sites 
located off of the continental shelf. See Section 102(a)(I) of the 
MPRSA and 40 CFR 228.5(d). Recent oceanographic research has 
demonstrated fragile and complex ecosystems in these deep ocean 
environments throughout the world. In the case of the Mouth of the 
Columbia River, the 1999 IFR/EIS explained that disposal of dredged 
materials in an off-shelf location would likely adversely impact the 
thriving, densely populated benthic and pelagic ecosystems in water 
depths of 600 feet or greater. Bottom gradients off-shelf are steep, 
between 5 and 25 percent on the continental slope, and accumulation of 
disposal materials which are unconsolidated would be likely to result 
in slumping and off-site impacts. Data from NOAA Fisheries indicate 
that the nearest off-shelf area, the Astoria Canyon, located 11 miles 
offshore, is unique habitat. NOAA Fisheries commented to that effect 
during scoping of site designation studies and again in response to the 
proposal. In looking at a zone of siting feasibility (ZSF), EPA and the 
Corps considered that information and those concerns and also 
considered other factors. Other factors included the authorized depth 
of the river channel, the availability of dredging equipment, and 
operational concerns, such as adverse weather conditions and the time 
needed to dredge material and haul it to disposal sites during the 
dredging season. The dredging season at the Mouth of the Columbia River 
is limited to the time period from June to October because of rough 
seas and adverse weather conditions that are the norm from November to 
May. Siting feasibility also took into account norms for the heaviest 
shoaling times at the Mouth of the Columbia River (generally July) and 
the need to avoid commercial fishing use areas during periods of high 
use. All of these factors contributed to the identification of the area 
within an arc 4.5 nautical miles seaward from river mile -1.0 as the 
extent of the location in which to seek to designate a site for 
disposal of dredged materials for the Mouth of the Columbia River.
    Baseline--EPA received numerous comments on EPA's baseline analysis 
for the site designations. EPA fully complied with the baseline 
requirements for site designation set forth in 40 CFR subchapter H, 
part 228 B ``Criteria for the management of disposal sites for ocean 
dumping.'' 40 CFR 228.13 ``Guidelines for ocean disposal site baseline 
or trend assessment surveys under section 102 of the Act,'' provides 
the following pertinent statements on baseline: ``The purpose of a 
baseline or trend assessment survey is to determine the physical, 
chemical, geological, and biological structure of a proposed or 
existing disposal at the time of the survey. A baseline or trend 
assessment survey is to be regarded as a comprehensive synoptic and 
representative picture of existing conditions; each survey is to be 
planned as part of a continual monitoring program through which changes 
in conditions at a disposal site can be documented and assessed.''
    This regulation also states: ``An initial disposal site evaluation 
or designation study should provide an immediate baseline appraisal of 
a particular site, but it should also be regarded as the first of a 
series of studies to be continued as long as the site is used for waste 
disposal.''
    The baseline studies at the DWS and SWS did provide a comprehensive 
synoptic and representative picture of the existing conditions at the 
time the sites were proposed for designation. The baseline appraisal 
monitoring is an ongoing, continuous process for the life of the site. 
This ongoing process is addressed through the restrictions on the use 
of each site in this designation and through the site monitoring and 
management plan (SMMP). Data contributing to the baseline are contained 
in the appendices to 1999 IFR/EIS, 2003 SEIS, and MEC's Biological 
Baseline Study and are supplemented by the Crab Entrainment Study and 
Trawl Comparison Study. EPA has met baseline data requirements for 
purposes of designating both the SWS and DWS. Physical, chemical, 
geological, and biological baseline surveys are considered to be 
complete for both the SWS and DWS. The SMMP contains a synopsis of the 
available physical and biological data. For the DWS, EPA believes that 
special studies may enhance EPA's understanding of the site. The types 
of special studies EPA requires are described in the final SMMP. 
Special studies may lead to additional management constraints on the 
use of the DWS depending on the results of such special studies. 
Routine monitoring as described in the final SMMP could also lead to 
additional site use constraints. The final SMMP includes monitoring and 
reporting to help manage conditions at designated sites through a 
continuous program of assessing changes in conditions at the sites. 
Annual use planning and reporting will supplement the information 
collected by EPA and the Corps through the SMMP.
    Commenters expressed the opinion that the baseline biological 
analysis for the DWS was flawed and that it failed to consider the DWS 
as an area of importance to flatfish nurseries and crab. The commenters 
contended that it's location in the shipping and ``tow lane'' makes the 
DWS usable as a nursery but not as a fishery. The ``tow lane'' referred 
to is the navigation route depicted on navigation charts as the route 
to be used by vessels towing other vessels such as barges or ships. EPA 
notes that the DWS was recommended as a potential disposal site by crab 
fishermen because the site was generally not fished and was not 
considered unique or special habitat as a nursery site. The biological 
baseline shows that the DWS provides some nursery habitat for fish and 
crab populations but establishes that the DWS is not unique or 
significant nursery habitat. The biological baseline for the DWS 
included a detailed assessment of living organisms and complied with 
the requirement to measure the benthic biota, including a quantitative 
and qualitative evaluation of benthic communities. These communities 
included macroinfauna and macroepifauna, meiobenthos, and microbenthos 
and an appraisal, based on existing information, of the sensitivity of 
the indigenous species to the dredged sediments proposed to be disposed 
at the site. In addition, trawl studies, conducted in 2003 further 
assessed the fish and crab population at the DWS. Refer to the final 
SMMP for the description of the baseline.
    The baseline for ocean dredged material site designation as 
required by the regulations is intended to present a ``snapshot'' in 
time of biological conditions at the site so that changes to those 
existing conditions can be monitored over time.
    Site Monitoring and Management Plan (SMMP)--EPA agrees with the 
recommendations from many commenters to revise the draft SMMP to 
include an adaptive management strategy and further assessment of 
biological impacts. The final SMMP specifies ``special studies'' 
intended to verify predicted material placement and mound configuration 
development and biological impacts at the DWS by measuring benthic 
infaunal succession, groundfish and macroinvertebrate (e.g., crab) use, 
as well as assessing specific placement techniques at the mound that 
will eventually be created over time at the DWS. The final SMMP has 
been completed by EPA and the Corps and

[[Page 10045]]

becomes effective with this designation. The SMMP and annual use plans 
will provide for periodic monitoring of the fish and crab population at 
the DWS in addition to other specific information collection. The 
annual use plans will be available to the public from EPA upon request. 
The SMMP and annual use plans will also provide for similar management 
of the SWS. The final SMMP was modified to enhance information 
collection related to impact analysis, monitoring and future management 
actions to sustain the aquatic environment. The information collected 
will be used to re-assess the nature and severity of the impacts of 
disposal at the sites and to make changes to how the sites are used, if 
necessary, and to assess whether the sites need to be changed.
    Some commenters expressed a preference for revising the SMMP to 
change the management of the DWS to confine disposed material at the 
DWS to as small an area as possible by the use of a ``pinpoint, 
repetitive dump method'' with an adaptive management approach to 
evaluate mound height after a single drop point at the DWS reached a 
mound height of 30 to 40 feet. EPA did not revise the final SMMP to 
provide for repetitive pinpoint dumping at the DWS because EPA 
disagrees with the commenters on this point and favors a more minimal 
impact to the ocean floor over the larger footprint of the site. EPA 
does not intend to allow for a rapid creation of individual 30 to 40 
foot mounds anywhere within the placement area but expects that 
gradual, uniform mounding at the DWS could reach such heights over 
fifty years of use or longer. Immediate mounding through repetitive 
pinpoint dumping would be expected to more severely impact benthic 
organisms through a rapid and dramatic change in floor height. 
Spreading the disposal material more widely and causing a slow change 
in ocean floor height is expected to be less disruptive to adjustment 
and recolonization efforts of indigenous benthic organisms at the site. 
However, the routine monitoring and special studies identified in the 
final SMMP will provide more definitive information on this issue and, 
if warranted, site use management will be adjusted.
    With respect to monitoring the DWS, EPA expects to use the SMMP, 
which addresses management and monitoring of both the SWS and the DWS, 
as the basis for annual use planning and reporting by site users. As 
part of the biological baseline work, four locations outside of the DWS 
were identified and sampled. Under the SMMP, these locations will be 
periodically revisited as part of ongoing monitoring and management of 
the site. EPA expects the buffer zone at the DWS to act as a reference 
site for monitoring. The four reference locations outside the DWS 
boundaries provide adequate backup to the buffer. Sloughing or 
spillover into the buffer is unlikely to occur until after many years 
of use of the site. However, EPA has decided to include an evaluation 
of the need for additional reference monitoring at any time the SMMP is 
reviewed.
    Columbia River Plume--EPA received several comments suggesting that 
site designations near the mouth of the Columbia River would have an 
impact on the Columbia River plume. The plume dynamics of the Columbia 
River plume were studied during the site selection process. A 
discussion in the ``Oceanographic Processes'' Sections 6 and 7 of 
Exhibit B ``Physical Processes and Geological Resources'' to Appendix H 
of the 1999 IFR/EIS explains that most of the dynamics of the Columbia 
River plume are confined to the upper 16 feet of the water column but 
can extend to a depth of 66 feet. Plume-induced currents are normally 
observed at or near the plume surface and decrease with depth. In 
addition to the depth-influenced limitation of the plume, there is 
significant seasonal change in ocean circulation affecting the plume. 
For example, the summer/fall (July to October) variation in the plume 
is influenced by low discharge from the Columbia River and a southerly 
circulation of the shelf waters.
    Because of comments received on the proposed site designations 
concerning the Columbia River plume, EPA reviewed the study by David 
Jay, C. Cudaback and T. Chisholm, ``Draft Report: Evaluation of Impacts 
of Maintenance Dredging at the Mouth of the Columbia River on Plume 
Salinity,'' June 2004 (Plume Study). The Plume Study identified the 
Columbia River Plume as a surface-advected plume and looked at the 
important implications of this plume type. The Plume Study found that 
``localized changes in flow depth caused by dredged material disposal 
will not directly affect the plume, as long as the changes in depth 
remain small relative to the total depth of the water underlying the 
plume.'' Significantly, the Plume Study results suggested: ``Changes in 
entrance depth [at the Mouth of the Columbia River] cannot change the 
total export of freshwater to the plume. The impacts of MCR maintenance 
on the plume are quite limited. Also, initial differences in the 
freshwater fraction produced in the MCR area are largely preserved as 
water parcels transit the plume near-field.'' Conclusions reached by 
the Plume Study included the following: ``Because the plume is highly 
mobile, variations in plume salinity, plume depth, and water parcel 
trajectories related to changes in coastal winds and currents are far 
larger than differences related to initial conditions in the MCR 
region. The effects of river-flow and tidal variability are also larger 
than those of MCR depth variability.'' And: ``Regardless of plume 
orientation (and dredging cycle), a continuum of salinities exists 
within a relatively small area between low initial plume salinities and 
ocean salinities, which vary only modestly with winds and currents.'' 
(Plume Study)
    Based on available data concerning the Columbia River plume 
environment, EPA does not expect the designation and use of the DWS or 
SWS to adversely impact the plume environment. Placement of dredged 
material within the SWS is not expected to affect circulation of the 
Columbia River plume within or outside of the site boundaries. Dredged 
material in the SWS will be spread over the site and limited in height. 
Dredged material placed in the SWS is expected to be dispersed within 
1-3 years, depending upon the volume placed per year and the flow from 
the Columbia River.
    A vertical accumulation of 4-6 feet of dredged material within a 
water depth of 45-65 feet will affect less than 10 percent of the water 
column. This is not expected to modify currents influencing the 
Columbia River plume.
    The Deep Water Site is designated on the floor of the mid-
continental shelf where water depths vary between 200 and 300 feet. At 
the top of the water column in the vicinity of the DWS, the surface 
water from the Columbia River plume is significantly modified by 
ambient coastal water. At the seafloor and at depth, these surface 
influences are not experienced although bottom currents are present. 
Over time, the size of the mound that may result from accumulated 
dredged material disposed at the DWS (expected to be in the range of 
20-40 feet high after many years of use) creates a potential for ocean 
bottom currents at the DWS to be slightly affected by the deposition of 
dredged material. Since some portion of the mixing zone for the plume 
of the Columbia River passes over the DWS, but is expected to remain 
separated vertically from the highest anticipated elevation of the DWS 
by at least 100 feet at all times, any change in circulation at the DWS 
is unlikely to affect the distribution of the Columbia River plume. The 
plume remains an area of interest and EPA and the Corps intend

[[Page 10046]]

to continue to assess the effects, if any, of maintenance of the Mouth 
of the Columbia River and lower Columbia River channel projects on the 
plume dynamics.
    Sediment Re-suspension and Transport--A commenter questioned 
whether sediment placed at the DWS remained immobile and questioned 
whether any movement of sediment might compromise use of the buffer as 
a reference area. Evaluation of sediment movement in the 1999 IFR/EIS 
and MCR Optimized Site Utilization Report for the MCR area provided 
strong evidence that bottom sediment movement is limited on the ocean 
floor at the DWS and would be unlikely to compromise the buffer as a 
reference area. However, EPA agrees with the recommendation to assess 
the movement of sediments at the DWS and has included this element in 
the SMMP. EPA intends to use the routine site management and 
monitoring, as described in the final SMMP, to assess potential 
remobilization of sediments placed at the DWS. The buffer zone at the 
DWS is an area within the designated boundaries to ensure that the 
sediment mass remains within the designated site boundaries. Because 
the buffer zone at the DWS will not be impacted immediately by the 
placement of dredged material, the buffer zone is considered a suitable 
reference area for monitoring potential remobilization for the 
foreseeable future. If routine monitoring reveals unanticipated changes 
to the sediment regime of the buffer zone, a more focused special study 
could be required. As part of the biological baseline work, four 
locations outside of the DWS were identified and sampled. These 
locations will be periodically revisited as part of routine monitoring. 
EPA expects the buffer zone at the DWS to act as a reference site for 
monitoring with the four reference locations outside the DWS boundaries 
providing adequate backup.
    Timing on Use of Sites--Commenters suggested that the time of year 
designated sites were used might be relevant to various fish life 
cycles given potential turbidity increases at the time of disposal. One 
commenter suggested that public notice and an opportunity for comment 
be allowed prior to disposal. EPA responds that public notice is 
required before sites can be used. The statute and regulations, as well 
as the procedural requirements the Corps follows to meet the 
substantive requirements for site use, all require public notice. EPA 
anticipates that the primary user of the DWS and SWS will be the Corps. 
For non-Corps use, ocean dumping cannot occur unless a permit is issued 
under the MPRSA. In the case of dredged material, the decision to issue 
a permit is made by the Corps Regulatory Program using EPA's 
environmental criteria and subject to EPA's concurrence. While the 
Civil Works and Operations Programs of the Corps do not issue 
themselves ``permits,'' Section 103(c) of the MPRSA requires that Corps 
projects apply the same criteria, factors to be evaluated, procedures, 
and requirements that apply to the issuance of permits. The Corps 
already has an established and comprehensive public involvement process 
in place for its Civil Works, maintenance and regulatory programs, 
including notice and an opportunity for comment. In all cases, specific 
concurrence is required from EPA.
    Timing at the SWS--Commenters asked that the location of the SWS 
relative to feeding, spawning, and migration areas for adult and 
juvenile salmonids address fish habitat and life cycle requirements and 
avoid habitat degradation through appropriate timing and volume of 
dumping of dredged materials. Commenters also asked that specific 
timing restrictions be established at the SWS to avoid impacts to soft 
shell crab. EPA does not conclude that a seasonal deadline for ending 
disposal use of the SWS is warranted based on existing data for the 
SWS. An August deadline for ending disposal each year at the SWS had 
been agreed to by the Corps in 1998 as part of a settlement agreement 
with the Columbia River Crab Fishermen Association (CRCFA). That 
agreement terminated by its provisions in mid-2004. Currently, there 
are no data to suggest that the August deadline bore a significant 
relationship to actual crab life cycles or fishery needs. Dredging 
times, and other site use conditions necessary to allow EPA to monitor 
and manage the site as described in the SMMP, will be established in an 
annual use plan for the site. Annual use plans will be developed by 
each site user as a mechanism to implement any conditions or practices 
necessary for management of the site. The dredge season for the SWS 
will be based on many factors. Indirectly, a time limit on site use 
already exists. The natural weather, wind, wave, current and tidal 
patterns create an optimal window for use of the site. This optimal 
window normally runs from the beginning of June to early October. These 
natural processes impact dredge operations and ship movement 
significantly.
    The location of the SWS relative to breeding, spawning, nursery, 
feeding, or passage areas in adult and juvenile phases was carefully 
assessed. The Corps has been using designated Site E and Expanded Site 
E, respectively, for the last 30 years and has disposed of 
approximately 50 million cubic yards (mcy) of dredged material at those 
sites within those years. The SWS is located in a highly dynamic area 
where current and waves allow the sediment to rapidly disperse into the 
littoral zone. Monitoring of the area over time has shown that the 
bottom elevations have not been adversely altered by disposal of 
dredged material. This means the water column available to adult fish 
for migration into spawning grounds or to juvenile fish for migration 
into the ocean environment has generally remained a constant. The 
timing of disposal activities to avoid habitat degradation will be 
factored into the use and management of the site.
    Size of the SWS--Several commenters asked that EPA clarify the size 
of the SWS. EPA provided the 1983 NAD coordinates for the SWS in 
section B, above, of this designation and is finalizing the site 
configuration at those coordinates. It appears from the comments that 
there was confusion over the description of the SWS in the proposed 
designation. The coordinates for the ``new Site E'' as presented in the 
voluntary NEPA documentation became the coordinates for the Shallow 
Water Drop Zone in the proposed designation. The Drop Zone occupies the 
identical footprint as the Corps 103-selected Expanded Site E, which 
incorporated the former Site E (de-designated in today's action). The 
SWS Placement Area represents the outer boundary of the site where 
dredged material, when released within the Drop Zone, will temporarily 
accumulate during active disposal, and from which dredged material is 
expected to erode back into the littoral system. The vertical 
configuration of the SWS is a trapezoid that is wider at the seabottom 
(Placement Area) and tapering inward to the surface (Drop Zone). The 
site, consisting of both the Drop Zone and Placement Area, encompasses 
1,198 acres or approximately 1.4 square nautical miles of seafloor. See 
Figure 2. EPA and Corps monitoring of the discharged sediment behavior, 
augmented by computer modeling, allowed EPA and the Corps to identify 
the accumulation pattern and specify the Placement Area (see MCR 
Optimized Site Utilization Report). Specification of the Drop Zone 
ensures that temporarily accumulating material remains within the same 
footprint affected by the use of the Expanded Site E. The Drop Zone 
will allow EPA to monitor and manage the dispersion of

[[Page 10047]]

disposed material throughout the site and will enable maximum site 
capacity to be used while avoiding the potential for adverse mounding.
    Size of the DWS--Several commenters urged EPA to minimize the 
bottom footprint of the DWS and to concentrate disposal in the smallest 
area possible until maximum acceptable mound height is reached at each 
pinpoint dump spot. EPA has seriously evaluated this concern. In 
reviewing the site designations at the Mouth of the Columbia River it 
is clear that the original sites--Sites A, B, E, and F--were each too 
small to accommodate the disposal needs at the Mouth of the Columbia 
River or to manage material allocations between the different sites in 
an effective manner. EPA is finalizing today's designations to plan for 
the long-term needs for disposal at the Mouth of the Columbia River. By 
sizing the DWS as proposed, EPA will be able to manage disposal at both 
the SWS and the DWS to avoid excessive mounding conditions with 
resultant potential for adverse impacts. The size of the DWS also 
allows the site to be managed to minimize the impact to the bottom 
biological environment. Allowing for a larger, rather than smaller, 
ocean floor footprint at the DWS should enable the biological 
environment to have the greatest opportunity to adapt to changes to the 
seafloor resulting from dredged material disposal over time. The larger 
footprint should also ensure long-term capacity negating the need for 
additional ocean sites for fifty years or more based on EPA and Corps 
projections for ocean disposal needs. EPA is finalizing the DWS as 
proposed. As part of its designation studies, EPA considered numerous 
locations and configurations of sites to meet the current and long-term 
needs of dredged material disposal near the MCR and surrounding locale.
    One commenter stated that EPA failed to meet MPRSA requirements by 
failing to justify the size of the DWS and incompletely analyzing the 
economic impact of the site designation. Ocean dumping regulations 
require that ocean disposal sites be sized so as to localize for 
identification and to control any immediate adverse impacts and to 
permit the implementation of effective monitoring and surveillance 
programs to prevent adverse long-range impacts. See 40 CFR 228.5(d). 
EPA has met this obligation under the regulations. The DWS is localized 
for identification and control, and the NAD 83 coordinates are provided 
to establish the parameters of the site. Clear identification of the 
site allows for the control of any immediate adverse impacts to the 
maximum extent practicable. Monitoring and site surveillance are 
feasible at the DWS. Site designations under section 102 of the MPRSA 
are generally intended to be long-term as compared to site selections 
under section 103 of the MPRSA, which have a five-year to maximum ten-
year life span. EPA's site designations are intended to minimize 
conflicts between disposal activities and other activities in the 
marine environment and are to avoid areas of existing fisheries or 
shellfisheries, and regions of heavy commercial or recreational 
navigation where practicable. The DWS has been located and sized with 
significant input from stakeholders, in particular commercial and 
recreational fishermen, to avoid those areas of existing fisheries that 
are most significant to those individuals, companies and organizations.
    Mounding at the SWS--Some of the commenters stated that mounding 
was an important issue for the proposed SWS and asked EPA to strictly 
limit mound-induced wave amplification to 10 percent and to consider 
the effects of large and long period swells as they interact with the 
site. These commenters referred to the area as ``the path of the last 
historic navigation route to the north site fishing grounds.'' EPA and 
the Corps have been concerned with the potential for mound-induced wave 
amplification at the SWS and have invested considerable effort in 
surveying the site and in computer modeling of the site under many 
scenarios to consider the effects of wind, wave (period, height, 
steepness, breaking), current and swell. See MCR Optimized Site 
Utilization Report.
    EPA and the Corps looked at the potential change in the wind-wave 
environment as it related to a change in the bathymetry (i.e. the 
seabed topography) when dredged material was disposed at the SWS. The 
assessment indicated that the complex interaction of forces at the site 
all had the potential to contribute to wave amplification and that 
mound-induced wave amplification alone could not account for total wave 
amplification at the site. The assessment suggests that selective 
uniform placement of dredged material at the site will eliminate 
undesirable impacts to the local wave environment by eliminating or 
significantly decreasing the potential to create mounds at the site. 
See MCR Optimized Site Utilization Report. Careful management of the 
timing and placement of dredged materials at the SWS should ensure that 
adverse conditions are not created.
    With respect to this area being used as an historic navigation 
route to northern fishing grounds, EPA notes that the U.S. Coast Guard 
considers the area near Peacock Spit to be an historically dangerous 
area that should be avoided by all vessels. Vessels transiting this 
area have always done so at great risk. No study or investigation of 
the disposal site in this area has ever found that the site or use of 
the site contributed to a hazardous situation for any mariner. The 
natural conditions themselves are very hazardous and there is no 
evidence to suggest that disposal in this area has increased those 
risks.
    Placement of the DWS--One commenter expressed general support for 
placement of the DWS in the ``towlane'' at the Columbia River but 
suggested that ``towlane'' coordinates should be used to ensure that 
active fishing grounds currently available to the commercial fishing 
fleet would be avoided. As referenced earlier, the ``tow lane'' 
referred to is the navigation route depicted on navigation charts as 
the route to be used by vessels towing other vessels, for example, 
barges or ships. EPA does not agree that ``towlane'' (or ``towboat 
lane'') coordinates should be used to define the DWS. The overall 
position of the DWS is generally in the towboat lane to avoid 
commercial and recreational fishing areas as much as possible; however, 
the offset of coordinates between the DWS and the towboat lane is 
necessary to avoid direct interference with navigation lanes. The 
potential for conflicts at the DWS with vessels transiting the area can 
be avoided by careful management and coordination with Columbia River 
bar pilots, the U.S. Coast Guard and others. Commercial and 
recreational fishery conflicts can be avoided and minimized through 
careful management of the site.
    Impact on Benthos at the DWS and SWS--One commenter suggested that 
disposal at the designated sites would have a potential permanent 
effect on benthic species, particularly crab. EPA does not agree that 
disposal activities will have a permanent effect on benthic species at 
either the SWS or the DWS given the adaptability of the species. 
Although crab are present at the SWS and the DWS, these sites do not 
differ in any substantive way from the ocean floor outside of the site 
boundaries available to crab and other benthic species. At the request 
of fishermen and fishing organizations, EPA avoided traditionally rich 
fishing grounds as the agency assessed the various alternatives in the 
1999 IFR/EIS. Special studies identified in the final SMMP will assess 
recolonization after disposals and (periodically) benthic populations. 
Depending on the results of the special studies, a biological component 
may be

[[Page 10048]]

added to the routine monitoring in the SMMP.
    One commenter observed that the full potential effects of dumping 
various volumes at the DWS and SWS had not been sufficiently reviewed 
and evaluated to include the concentration of the material at the 
sites. EPA did assess the potential effects of dumping various volumes 
of material at the DWS and SWS (see 1999 IFR/SEIS; see also MCR 
Optimized Site Utilization). EPA and the Corps used computer modeling 
to provide estimates of the potential volumes the SWS could accommodate 
under numerous scenarios to ensure that use of the site would not 
potentially contribute to adverse conditions similar to those 
experienced at Sites A, B and F. A report was produced from these 
studies. The MCR Optimized Site Utilization report concludes that while 
the capacity for the SWS is much higher than originally anticipated, 
the dispersive conditions are dependent on the placement of sediment at 
the site. Generally there is seasonal dispersion from the site into the 
littoral zone but storm conditions can impact the rate and trend of the 
dispersion. The DWS is sized to handle volumes for the long-term needs 
for disposal of sediments from dredging operations near the MCR and the 
channel of the Columbia River. This includes capacity for those times 
during dredge seasons when the SWS is not available. The full effects 
have been reviewed as required for site designations. At the DWS, these 
effects include the anticipated loss of benthic organisms that are 
directly disposed upon but little to no impact on benthic organisms not 
directly disposed on. The DWS will be managed to avoid impacting the 
entire site at one time. This use of the site is expected to provide 
the best opportunity for benthic organisms at the site to adapt to new 
conditions and to recolonize those areas that are disposed on directly.
    Cumulative Effects--Commenters stated that cumulative effects had 
not been fully assessed to account for environmental and economic 
effects including a consideration of the SWS and DWS, the Mouth of the 
Columbia River maintenance project, the Columbia River channel 
improvement project, effects of jetties, dams, wetland diking, and 
other substantial human alterations to the sediment budget and 
transport of the area, as well as past temporary ocean disposal by the 
Corps. Cumulative effects were addressed in the 1999 IFR/EIS and 2003 
SEIS. One commenter also contended cumulative sediment fate analysis 
was not adequate to determine sediment movement in and around Columbia 
River with any degree of certainty. Although EPA did use sediment fate 
analysis in its analysis, EPA did not rely solely on sediment fate 
analysis to determine sediment movement. EPA's analysis included an 
assessment of oceanographic processes, including offshore regional 
scale circulation, inner shelf circulation, seasonal changes in 
circulation, long-period waves, offshore rotary currents and littoral 
sediment supply and transport. Measured oceanographic data included 
hydrographic survey data, textural characteristics of sediments, 
seasonal variation of bottom sediments and measured current and seabed 
change data which provided sufficient data to allow for an adequate 
analysis of cumulative effects.
    Safety at the SWS--Some commenters asked whether potential mounding 
and wave amplification had been adequately studied at the SWS. The SWS 
has been studied in detail both via surveys and modeling. Suggestions 
that mariners historically used this area without any navigational 
problems prior to dumping are not accurate. Studies done for EPA by the 
Corps, the Coast Guard, and independent safety teams strongly agree 
that the area near Peacock Spit is a naturally rough surf-zone area 
generally to be avoided by vessels at all times. EPA is designating the 
SWS without changes from the proposed designation but agrees that 
management of disposal at the SWS needs to include placement of dredged 
sediments to ensure that mounding conditions are not created that might 
contribute to adverse conditions at this dynamic site. By nature, the 
site is not suitable for navigation by small vessels; however, there 
are no known situations where disposal at Site E or Expanded Site E 
contributed to the navigational difficulties of this naturally risky 
area. Recent computer modeling at the site at EPA's request resulted in 
an optimized use pattern for disposal taking seasonal variation of 
current and storm conditions into account. This optimized use strategy 
is included in the SMMP and will be included in annual use plans 
developed by site users.
    Crab Impact at the SWS and DWS--Several commenters addressed the 
issue of crab impacts from sediment disposal at the SWS. One commenter 
suggested that past dumping activities at the SWS interfered with 
fishing and depleted the crab populations. EPA disagrees and has found 
no data to substantiate such an impact nor has any such data been 
provided. EPA studied crab as part of the designation studies (1999 
IFR/EIS, Appendix H) and biological baseline studies. The biological 
baseline study using trawls and crab pots provides population 
estimates, seasonal variation in crab population, and comparisons of 
crab numbers at the proposed sites to the area generally. The 
laboratory crab burial studies evaluated the impact of dredged material 
disposal on soft-shelled crab.
    The extremely dynamic SWS showed relatively constant percentages of 
male crab in pots from July to September 2002. Additionally, crabs were 
larger in September at the end of the molting season. No pattern of 
differential site use was detected even though active placement of 
dredged material was taking place at the site during the 2002 dredging 
season. The trawls at the SWS exhibited an increase in the number of 
males from July to October 2002 along with an increase in hard crab. 
Crab were not found in the DWS in great numbers in the July 2002 survey 
but were abundant during the September 2002 sampling episode. Increased 
abundance of crab in the trawls and pots was observed primarily at the 
shallower portion of the site in September 2002. This is consistent 
with previous studies. EPA will continue to assess the need to evaluate 
the crab resource at the SWS and DWS as part of its management and 
monitoring activities.
    Commenters asked about the crab data at the DWS. Some commenters 
suggested that the data collected showed crab abundance was dense at 
the DWS in the late summer with recently molted soft-shelled crabs. 
Field surveys were conducted in 2002 and fish and macroinvertebrate 
sampling was expanded in 2003 to include both beam trawls and 
commercial sized otter trawls. Sampling a given population with 
multiple methods is done to ensure that an adequate assessment of a 
population structure and composition has been completed. In this case 
the results obtained indicated that the DWS was typical of most inner 
to middle continental shelf communities found off Oregon and Washington 
and did not provide unique habitat or species. Comparing this sampling 
event with over 20 years of historic data (see 1999 IFR/EIS, Appendix 
H) further substantiates the conclusion that the habitat and community 
structure of the DWS is typical of most ocean areas offshore of the 
States of Oregon and Washington. EPA's ongoing management and 
monitoring should help to ensure that any adverse effects to this 
species are minimized.
    Navigation Maintained--One commenter stated that the designation of 
the SWS and DWS, with their combination of dispersive and non-
dispersive characteristics, met the need for proper channel maintenance

[[Page 10049]]

allowing safe passage for all vessels crossing the bar at the Mouth of 
the Columbia River. This commenter also said that EPA demonstrated 
responsiveness to local concerns about navigation impacts by proposing 
to de-designate sites A, B and F and to address local navigation 
concerns by designating the proposed SWS using material dispersal 
patterns in the site design. EPA's site designations and de-
designations finalized today are intended to best meet the concerns for 
navigation impacts and management of dredged material. Another 
commenter stressed the importance of safety for all types and sizes of 
marine vessels entering and exiting the Mouth of the Columbia River and 
commented that the proposed actions would provide safe passage for 
maritime use and preserve the Mouth of the Columbia River's role as a 
``gateway to the world for international trade'' and a ``vital part of 
the nations'' transportation system.'' EPA agrees that providing new 
designated sites for dredged materials and de-designating existing 
sites will contribute to safety for vessels of all types and sizes.
    Monitoring at the DWS--Commenters expressed concerns about the 
feasibility of monitoring the site given its size and depth. EPA 
appreciates this concern and has structured the SMMP to ensure that 
monitoring activities at the site will be feasible.
    DWS Buffer--Several commenters questioned the need for the DWS 
buffer. EPA is finalizing the DWS with the buffer. The buffer will 
serve primarily as a reference location. Over time, a 40-foot-high 
trapezoidal mound will likely be created through disposal activities. 
EPA has conservatively assumed that the mound will at times be subject 
to slippage on the edges and that some spillover, over time, must be 
expected into the DWS buffer. The buffer will act to ensure that 
sediments placed at the DWS will not move beyond the site boundaries. 
Data collected at the DWS indicate extremely minimal bottom sediment 
movement once the sediments have deposited on the bottom. Disposal 
sequencing into the DWS will be conducted and evaluated to keep any 
potential spillover minimal. EPA believes that disposal immediately and 
over time should not impact the buffer's role as a primary reference 
location. EPA expects that future and routine modeling will detect the 
potential for sediment encroachment into the buffer well before it 
might occur. This should allow the adaptive management process in the 
SMMP to make corrections or to implement contingencies. During the 
designation studies, four locations outside of the DWS were sampled. 
These locations could serve as suitable references should any of the 
stations within the buffer become compromised. These four locations 
will be periodically re-sampled and reassessed as part of ongoing 
monitoring at the DWS, either as part of a routine monitoring event or 
as a special study, but it is not expected that the four stations would 
be reoccupied each and every year.
    DWS as a Contingency Site--Some commenters asked EPA to designate 
the DWS as a contingency site to be used only when all other options 
were exhausted. EPA is not designating the DWS specifically as a 
contingency site. It should be clear from the 1999 IFR/EIS and 2003 
SEIS that beneficial uses of the dredged material at near-shore sites 
are preferred before material is placed in deep water. This preference 
does not negate the need for the DWS as a necessary site to manage 
dredged material at the Mouth of the Columbia River and lower Columbia 
River. The few available near-shore sites do not have the capacity to 
accommodate the millions of cubic yards of material dredged annually 
and needing to be disposed of. The DWS provides a location for 
materials that cannot be otherwise accommodated. This final designation 
of the DWS will make the site available for use for dredged materials 
meeting the ocean dredged material disposal requirements.
    Sediment Size at the DWS--Commenters expressed concern that the 
disposal of sediment at the DWS would involve coarser sediment than 
occurs naturally and that benthic species at the site, especially crab, 
may be unlikely to recover from burial by the coarser sediments. The 
difference in sediment size between the grain size currently on the 
ocean floor at the DWS was identified as a ``Potential Conflict'' 
during the site assessment phase of the site evaluation study (1999 
IFR/EIS, Appendix H). Grain size sampling, as documented in the 1999 
IFR/EIS and 2003 SEIS, has shown that the sediments being dredged are 
generally in the size range of 0.12 mm at the outer shoal at the Mouth 
of the Columbia River to less than 0.35 mm in the Columbia River 
channel. The grain size at the DWS, pre-disposal, generally decreases 
with depth. Grain size observed during the biological baseline also 
fluctuated with the season. Sediments were finer during the September 
2002 sampling compared to the July 2002 sampling event. Finer sediment 
appears to be deposited during the calmer months and then appears to be 
winnowed and redistributed during rougher sea conditions. Various 
studies at the Mouth of the Columbia River found that material placed 
in depths greater than 80 feet are rapidly (within 6 months to a year) 
covered by ``native material.'' This has been documented for coarse 
grained and fine grained dredged material placed offshore of the Mouth 
of the Columbia River.
    The placement of coarser grained material at the DWS is not 
expected to cause an adverse impact to the environment. Grain size and 
disposal impacts to the benthic community will be among the parameters 
monitored at the DWS once the site is used. EPA has explained that 
species will be impacted by initial burial. Part of site management 
will involve spreading the sediment load to allow impacted benthic 
organis