National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List: Deletion of the Old Southington Landfill Superfund Site, 34513-34520 [2018-15628]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 83, Number 140 (Friday, July 20, 2018)]
[Proposed Rules]
[Pages 34513-34520]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-15628]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 300

[EPA-HQ-SFUND-2005-0011; FRL-9981-02--Region 1]


National Oil and Hazardous Substances Pollution Contingency Plan; 
National Priorities List: Deletion of the Old Southington Landfill 
Superfund Site

AGENCY: U.S. Environmental Protection Agency (EPA).

ACTION: Proposed rule; notice of intent.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) Region 1 is 
issuing a Notice of Intent to Delete the Old Southington Landfill 
Superfund Site (Site) located at Old Turnpike Road, Southington, 
Connecticut (CT), from the National Priorities List (NPL) and requests 
public comments on this proposed action. The NPL was promulgated 
pursuant to Section 105 of the Comprehensive Environmental Response, 
Compensation, and Liability Act (CERCLA) of 1980, as amended, is an 
appendix of the National Oil and Hazardous Substances Pollution 
Contingency Plan (NCP). The EPA and the State of Connecticut, through 
the CT Department of Energy and Environmental Protection (CT DEEP), 
have determined that all appropriate response actions under CERCLA, 
other than operation and maintenance, monitoring, and five-year 
reviews, have been completed. However, this deletion does not preclude 
future actions under CERCLA.

DATES: Comments must be received by August 20, 2018.

ADDRESSES: Submit your comments, identified by Docket ID no. EPA-HQ-
SFUND-2005-0011, by one of the following methods:
     Online: https://www.regulations.gov_Follow on-line 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. The EPA may publish any 
comment received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. The EPA 
will generally not consider comments or comment contents located 
outside of the primary submission (i.e., on the web, cloud, or other 
file sharing system). For additional submission methods, the full EPA 
public comment policy, information about CBI or multimedia submissions, 
and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
     Email: [email protected] or [email protected].
     Mail:

Almerinda Silva, U.S. EPA, Region 1--New England, 5 Post Office Square, 
Suite 100, Mail Code OSSR-07-4, Boston, MA 02109-3912
ZaNetta Purnell, U.S. EPA, Region 1--New England, 5 Post Office Square, 
Suite 100, Mail Code OSSR-ORA01-1, Boston, MA 02109-3912

     Hand delivery: U.S. EPA, Region 1--New England, 5 Post 
Office Square, Suite 100, Boston, MA. Such deliveries are only accepted 
during the Docket's normal hours of operation, and special arrangements 
should be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID no. EPA-HQ-SFUND-
2005-0011. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
https://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through https://www.regulations.gov or email. The https://www.regulations.gov website is 
an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an email comment directly to EPA without 
going through https://www.regulations.gov, your email address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses.
    Docket: All documents in the docket are listed in the https://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, i.e., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in the hard 
copy. Publicly available docket materials are available either 
electronically in https://www.regulations.gov or in hard copy at:
    U.S. EPA Region 1--New England, Superfund Records Center, 5 Post 
Office Square, Suite 100, Boston, MA 02109, Phone: 617-918-1440, Hours: 
Monday- Friday: 9:00 a.m.-5:00 p.m., Saturday and Sunday--Closed.
    Southington Public Library, 255 Main Street, Southington, CT, 
Phone: 860-628-0947, Hours: Monday-Thursday 9:00 a.m.-9:00 p.m., 
Friday-Saturday 9:00 a.m.-5:00 p.m., and Sunday Closed.

FOR FURTHER INFORMATION CONTACT:  Almerinda Silva, Remedial Project 
Manager, U.S. Environmental Protection Agency, Region 1--New England 
OSRR07-4, 5 Post Office Square, Boston, MA 02109-3912, Phone: (617) 
918-1246, email [email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction
II. NPL Deletion Criteria
III. Deletion Procedures
IV. Basis for Intended Site Deletion

[[Page 34514]]

I. Introduction

    EPA Region 1 announces its intent to delete the Old Southington 
Landfill Superfund Site from the National Priorities List (NPL) and 
requests public comment on this proposed action. The NPL constitutes 
Appendix B of 40 CFR part 300 which is the National Oil and Hazardous 
Substances Pollution Contingency Plan (NCP), promulgated by EPA 
pursuant to Section 105 of the Comprehensive Environmental Response, 
Compensation and Liability Act (CERCLA) of 1980, as amended. EPA 
maintains the NPL as the list of sites that appear to present a 
significant risk to public health, welfare, or the environment. Sites 
on the NPL may be the subject of remedial actions financed by the 
Hazardous Substance Superfund (Fund). As described in 40 CFR 
300.425(e)(3) of the NCP, sites deleted from the NPL remain eligible 
for Fund-financed remedial actions should future conditions warrant 
such actions. EPA will accept comments on the proposal to delete this 
site for thirty (30) days after publication of this document in the 
Federal Register.
    Section II of this document explains the criteria for deleting 
sites from the NPL. Section III discusses procedures that EPA is using 
for this action. Section IV discusses the Old Southington Landfill 
Superfund Site and demonstrates how it meets the deletion criteria.

II. NPL Deletion Criteria

    The NCP establishes the criteria that EPA uses to delete sites from 
the NPL. In accordance with 40 CFR 300.425(e), sites may be deleted 
from the NPL where no further response is appropriate. In making such a 
determination pursuant to 40 CFR 300.425(e), EPA will consider, in 
consultation with the State, whether any of the following criteria have 
been met:
    i. Responsible parties or other persons have implemented all 
appropriate response actions required;
    ii. all appropriate Fund-financed response under CERCLA have been 
implemented, and no further response action by responsible parties is 
appropriate; or
    iii. the remedial investigation has shown that the release poses no 
significant threat to public health or the environment and, therefore, 
the taking of remedial measures is not appropriate.
    Pursuant to CERCLA Section 121(c) and the NCP, EPA conducts five-
year reviews to ensure the continued protectiveness of remedial actions 
where hazardous substances, pollutants, or contaminants remain at a 
site above levels that allow for unlimited use and unrestricted 
exposure. EPA conducts such five-year reviews even if a site is deleted 
from the NPL. EPA may initiate further action to ensure continued 
protectiveness at a deleted site if new information becomes available 
that indicates it is appropriate. Whenever there is a significant 
release from a site deleted from the NPL, the deleted site may be 
restored to the NPL without application of the Hazard Ranking System.

III. Deletion Procedures

    The following procedures apply to deletion:
    (1) EPA consulted with the State before developing this Notice of 
Intent to Delete;
    (2) EPA has provided the State 30 working days for review of this 
notice prior to publication of it today;
    (3) In accordance with the criteria discussed above, EPA has 
determined that no further response is appropriate;
    (4) The State has concurred with deletion of the Site from the NPL;
    (5) Concurrently with the publication of this Notice of Intent to 
Delete in the Federal Register, a notice is being published in a major 
local newspaper, The Southington Observer. The newspaper notice 
announces the 30-day public comment period concerning the Notice of 
Intent to Delete the Site from the NPL; and
    (6) The EPA placed copies of documents supporting the proposed 
deletion in the deletion docket and made these items available for 
public inspection and copying at the Site information repositories 
identified above.
    If comments are received within the 30-day public comment period on 
this document, EPA will evaluate and respond appropriately to the 
comments before making a final decision to delete. If necessary, EPA 
will prepare a Responsiveness Summary to address any significant public 
comments received. After the public comment period, if EPA determines 
it is still appropriate to delete the Site, the Regional Administrator 
will publish a final Notice of Deletion in the Federal Register. Public 
notices, public submissions and copies of the Responsiveness Summary, 
if prepared, will be made available to interested parties and in the 
Site information repositories listed above.
    Deletion of a site from the NPL does not itself create, alter, or 
revoke any individual's rights or obligations. Deletion of a site from 
the NPL does not in any way alter EPA's right to take enforcement 
actions, as appropriate. The NPL is designed primarily for 
informational purposes and to assist EPA management. Section 
300.425(e)(3) of the NCP states that the deletion of a site from the 
NPL does not preclude eligibility for future response actions, should 
future conditions warrant such actions.

IV. Basis for Site Deletion

    The following information provides EPA's rationale for deleting the 
Site from the NPL:

Site Background and History

CERCLIS ID: CTD980670806
    The Old Southington Landfill Superfund Site is in the Town of 
Southington, Hartford County, Connecticut, and is approximately 13 
miles southwest of Hartford, Connecticut. From 1920 to 1967, residents 
and area businesses used portions of the landfill for disposal of waste 
materials. During this time frame, the landfill was known as the Old 
Turnpike Landfill. Based upon historical information, Remedial 
Investigation (RI) data, and differences in ownership between the 
northern and southern portion of the Site, it is clear that the 
northern and southern portions of the landfill were used for distinct 
and separate purposes. The northern portion of the landfill was a 
``stump dump'' that was used for the disposal of wood and construction 
debris. The southern portion of the landfill was used throughout the 
period the landfill was in operation for the co-disposal of municipal 
and industrial waste. Historical information, interviews with current 
and past Town employees, and information contained in public documents 
on disposal practices indicate that for a short period of time (1964-
1967) two areas (SSDA 1 and SSDA 2) in the southern portion of the 
landfill were used for disposal of semi-solid industrial wastes. In 
1967 (or shortly thereafter), the landfill was ``closed'' consisting 
of: Compacting disposed material, covering with 2 feet of clean fill, 
and seeding for erosion control.
    Between 1973 and 1980, the landfill property was subdivided and 
sold for residential and commercial development. Several residential 
and commercial buildings were built on the Site and on adjacent areas.
    The landfill is located approximately 700 feet southeast of the 
former Production Well No. 5, which was installed in 1965 by the Town 
of Southington Water Department and was used as a public water supply. 
The Connecticut Department of Public

[[Page 34515]]

Health and Addiction Services (then the Department of Health Services) 
sampled Well No. 5 on several occasions between December 1978 and March 
1979. Analyses of the samples indicated the presence of chlorinated 
volatile organic compounds (VOCs). Because of the detection of 1,1,1-
trichloroethane (TCA) at levels that exceeded State standards, Well No. 
5 was closed in August 1979. The well has been permanently closed since 
that time. A more detailed description of the Site history can be found 
in Section 1 of the Supplemental Remedial Investigation (SRI) Report 
(Kleinfelder, May 2006).
1. History of CERCLA Enforcement Activities
    In February 1980, EPA authorized a hydrogeologic investigation 
aimed at defining the nature and extent of contamination in groundwater 
in the vicinity of Well No. 5. Analysis of groundwater samples 
collected from two monitoring wells installed between the landfill and 
Well No. 5 indicated the presence of VOCs (Warzyn Engineering, Inc., 
1980). In November 1980, the Connecticut Department of Environmental 
Protection (now the CT DEEP) collected soil samples from a manhole 
excavation within the industrial park located on land that had 
previously been part of the landfill. Analysis of the soil samples 
indicated the presence of chlorinated and non-chlorinated VOCs.
    The Old Southington Landfill was formerly known as the Old Turnpike 
Landfill. Based on the above findings and a hazardous ranking 
evaluation performed in 1982, EPA subsequently proposed the Site be 
placed on the National Priorities List (NPL), pursuant to Section 
105(8)(b) of the Comprehensive Environmental Response, Compensation and 
Liability Act (CERCLA), 42 U.S.C. 9605(8)(b). On September 8, 1983, the 
Site was proposed to the NPL (48 FR 40674) and on September 21, 1984, 
the Old Turnpike Landfill was final listed on the NPL as the Old 
Southington Landfill Superfund Site (49 FR 37070). The Site includes 
two Operable Units (OUs); OU1 includes the landfill cap and permanent 
relocation of all on-site homes and businesses; and OU2 includes the 
groundwater.
    In 1987, EPA entered into an Administrative Order on Consent (AOC) 
with three Potentially Responsible Parties (PRPs) to define the nature 
and extent of Site contamination. In 1993, the PRPs prepared a Remedial 
Investigation/Feasibility Study report (ES&E, 1993) that provided 
results of the RI, a Human Health Risk Assessment (HHRA), an Ecological 
Risk Assessment (ERA), and a Feasibility Study (FS). EPA issued an 
Addendum to the RI/FS Report in 1994.
    In September 1994, EPA issued the Interim Remedial Action for 
Limited Source Control Record of Decision (ROD) that addressed the 
landfill and included the following major remedy components and remedy 
objectives:
     Relocation of existing residences and businesses located 
on top of the landfill;
     Construction of a synthetic cap over the landfill to 
prevent human contact with contaminated subsurface soils, stop 
rainwater infiltration through the soil to the groundwater, and allow 
for the containment and collection of landfill gas;
     Excavation and consolidation of a highly contaminated area 
``hot spot'' in a lined cell underneath the landfill cap;
     Removal of all buildings from the landfill;
     Installation of a soil gas collection system;
     Performance of long-term operation and maintenance (O&M);
     Performance of long-term monitoring;
     Development and implementation of institutional controls 
to ensure the remedy integrity by controlling future Site use and 
access; and
     Five-Year Reviews.
    The remedy selected in the 1994 ROD also required additional 
groundwater studies be undertaken concurrent with the implementation of 
the cap on the landfill. In addition, because it was uncertain if the 
landfill gas collection system would be effective and protective of 
human health, the 1994 ROD required that an additional evaluation be 
conducted.
    In 1998, a Consent Decree (CD) was entered between EPA and 
approximately 320 PRPs; two PRPs became the Performing Settling 
Defendants (PSDs) while the remainder were Contributing Settling 
Defendants. Pursuant to the CD, the PSDs were required to implement the 
remedy selected in the 1994 ROD. Construction of the remedy selected in 
the 1994 ROD was completed in 2001. Operation and maintenance as well 
as long-term monitoring are currently being conducted by the Performing 
Settling Defendants (PSDs). Institutional controls, consisting of 
Environmental Land Use Restrictions (ELURs), were implemented in 2010 
and 2018 for parcels occupied by the landfill cap. Five-Year Reviews 
are being conducted by EPA. In June 1999, EPA entered into two 
additional settlements: One with six parties and the other with 119 de 
minimis parties who all agreed to contribute to the cost of the 
remedial action in the 1994 ROD. Per the 1994 ROD, the PSDs performed 
the additional groundwater studies (i.e., a second RI/FS) to address 
the remaining issues at the Site under the 1998 CD. Accordingly, in 
1999, the PSDs initiated the Supplemental Groundwater Investigations 
(SGI) which was completed in 2006. The 2006 SRI and the Amended 
Feasibility Study (AFS), (EPA, 2006) were completed in June 2006. In 
September 2006, a Final ROD was issued to address potential vapor 
intrusion risks from contaminants located in shallow groundwater 
(Operable Unit 2 [OU2]).
    The 2009 CD required the PSDs to develop the Remedial Design and 
construct the selected remedy for the 2006 ROD. As part of the Remedial 
Design, a vapor intrusion groundwater investigation was completed for 
two properties immediately downgradient of the landfill that determined 
only vinyl chloride slightly exceeded a proposed State groundwater 
quality commercial/industrial volatilization criterion. Institutional 
controls in the form of ELURs would be implemented to prevent 
construction of new buildings to prevent future vapor intrusion risks 
(LEA, 2014). The ELURs were completed during 2017.

Remedial Investigation and Feasibility Study (RI/FS)

1. 1993 Remedial Investigation
    Results from the 1993 RI concluded that the primary sources of 
groundwater contamination at the Site are wastes, including liquid 
organic solvents and semi-solid organic sludges, deposited in the 
landfill during its operation. Deposition of limited amounts of metal-
containing wastes has also contributed to localized areas of elevated 
levels of certain metals in groundwater beneath the landfill.
    Overall, the RI results indicated that industrial-related chemical 
waste was deposited primarily in the southern portion of the landfill. 
VOCs were detected in soils at sporadically high concentrations 
throughout this portion of the landfill. VOCs were detected in shallow, 
intermediate, and deep overburden groundwater exceeding the federal 
Maximum Contaminant Levels (MCLs).
    Low to moderate concentrations of several other contaminants, 
including semi-volatile organic compounds (SVOCs) [primarily polycyclic 
aromatic hydrocarbons (PAHs)], polychlorinated biphenyl compounds 
(PCBs) and some metals, were also detected. The 1993 RI

[[Page 34516]]

also identified two areas (SSDA 1 and SSDA 2), where semi-solid 
industrial waste materials contaminated with relatively high levels of 
VOCs and/or SVOCs were deposited. EPA determined that SSDA 1 was to be 
considered a ``hot spot'' due to contaminants levels being 
substantially higher than those found throughout the landfill, whereas 
levels of contamination in SSDA 2 were consistent with those found 
throughout the southern portion of the landfill. Past records and 
results also indicated that the northern portion of the landfill was 
primarily used as a dump for stumps and demolition debris with waste 
materials including wood, ash, cinders, and some brick and asphalt. 
Moderate concentrations of PAHs were detected in soils at certain 
locations in the northern portion of the landfill. Approximately one 
third of the waste in the southern portion of the landfill remains 
below the water table.
2. 2006 Supplemental Remedial Investigation (OU2)
    The results of the 2006 SRI confirmed that groundwater flow beneath 
the landfill is westerly; however, as groundwater flows away from the 
landfill towards the Quinnipiac River, the flow becomes northwesterly. 
Groundwater present near the Site includes an overburden aquifer and a 
bedrock aquifer. Overall, groundwater flow was postulated to generally 
follow the bedrock topography, flowing along a west-northwest trending 
bedrock trough, with the impact of the bedrock topography being 
potentially greater on the flow in the deeper portions of the aquifer. 
Hydrogeologic evaluations also indicated that the bedrock surface rises 
in the western part of the area studied, pinching out the overburden 
groundwater aquifer west of the Quinnipiac River.
    Groundwater migrating westward from the Site contains dissolved 
contaminants derived from the waste disposed in the southern portion of 
the Site, and flows relatively quickly downward into the deeper 
overburden aquifer. This phenomenon appears to be due to significant 
differences in the relatively low permeability of the waste versus the 
high permeability of the underlying sand and gravel layer. Contaminants 
are then transported at depth to the west by regional groundwater flow. 
Contaminants from the northern portions of the landfill move downward 
more slowly and migrate greater distances through the shallow aquifer 
immediately west and northwest of the landfill.
3. 1994 Feasibility Study (OU1)
    Using the information gathered from the 1993 RI, HHRA, and other 
technical documents, EPA identified several source control response 
objectives to use in developing alternatives to prevent or minimize the 
release of contaminants from the Site. A comprehensive evaluation of 
containment and management of contaminated groundwater migration from 
the landfill was addressed by the final response action. A presumptive 
remedy for CERCLA municipal landfills was selected, which consisted 
primarily of containment (capping) of the landfill waste and gas 
collection/treatment. Capping of the landfill waste along with 
collection of landfill gases, and if necessary, treatment, was the 
presumptive containment remedy selected in the FS for this Site. In 
this FS, the remedy was combined with other remedial actions that 
addressed source control of the landfill wastes. The presumptive remedy 
did not address exposure pathways outside the source area (landfill) 
such as groundwater. The following 2006 Amended Feasibility Study 
addressed groundwater.
4. 2006 Amended Feasibility Study (OU2)
    In 2006, an Amended Feasibility Study (AFS) developed remedial 
alternatives for the remediation of groundwater, provided a detailed 
evaluation on the remedial alternatives, and performed a comparative 
analysis of the two remedial alternatives identified as (1) Alternative 
GW-1: No Action, and (2) Alternative GW-2: Institutional Controls/
Groundwater Monitoring/Building Ventilation/Vapor Barriers. Alternative 
GW-2 was chosen as the selected groundwater remedy for the Site.

Selected Remedies

    The September 1994, ROD for the Interim Remedial Action for Limited 
Source Control addressed the following Remedial Action Objectives 
(RAOs):
     Minimize the current and future effects of landfill 
contaminants on groundwater quality, specifically, reducing to a 
minimum the amount of precipitation allowed to infiltrate through the 
unsaturated waste column and contaminate the groundwater;
     eliminate potential future risks to human health through 
direct contact with landfill contaminants by maintaining a physical 
barrier;
     control surface water run-on, run-off, and erosion at the 
Site;
     prevent risks from uncontrolled landfill gas migration and 
emissions;
     comply with state and federal applicable or relevant and 
appropriate requirements (ARARs); and
     minimize potential impacts of implementing the selected 
limited source control alternative on adjacent surface waters and 
wetlands.
    Additional groundwater studies followed and in September 2006, EPA 
issued a ROD for the final selected remedy that addresses potential 
risks from vapor intrusion into buildings above the shallow VOC plume 
in groundwater (2006 ROD). This remedy addressed the following remedial 
action objective (RAO): Prevent inhalation of VOCs by occupants of 
residential/commercial/industrial buildings resulting from 
volatilization of VOCs in groundwater, in excess of 10 -4 to 
10 -6 cancer risk, a Hazard Index >1, and/or comply with 
applicable or relevant and appropriate volatilization criteria.
Response Actions
1. 1994 ROD Findings & Remedial Activities
    The remedial action selected in the 1994 ROD (for OU1, the 
landfill) was based principally upon EPA's Presumptive Remedy for 
CERCLA Municipal Landfill Sites, EPA Document No. 540-F-93-035. 
(Presumptive Remedy Guidance) (EPA, 1993). The 1994 ROD addressed all 
affected media (i.e., soil, soil gas, surface water, and sediment) at 
the landfill, at the adjacent Black Pond, and at the Unnamed Stream 
across Old Turnpike Road west of the landfill. By July 2001 physical 
construction of the OU1 (landfill) remedy was substantially completed 
and the operation and maintenance (O & M) activities and long-term 
monitoring (LTM) had started.
    The northern 4-acre portion of the landfill Site was redeveloped 
for passive recreational use. This part of the landfill is landscaped 
with trees and shrubs along its perimeter and abuts Black Pond. It is 
regularly mowed by the Town of Southington (a PSD). There is a 3-foot 
high chain link fence that encircles this part of the landfill along 
Old Turnpike Road to the west and Rejean Road to the north. The fence 
has an opening, which allows for pedestrian access. People can walk 
their dogs, sit and watch the naturally existing wildlife, and/or take 
their kayak or canoe out onto Black Pond. The southern portion of the 
landfill is secured with a 6-foot high chain link fence and public 
access is not allowed. The reason for prohibiting public access to this 
part of the landfill is to prevent potential damage to the low-
permeability cap, which could in turn

[[Page 34517]]

allow rainwater infiltration and direct contact with highly 
contaminated industrial waste.
    The 2006 SRI determined that there were no receptors downgradient 
of the Site that could be affected by the plume and that Site-related 
groundwater contaminants of concern (COCs) downgradient of the Site do 
not adversely impact environmental media other than groundwater. 
Groundwater COCs are transported as a narrow plume in the lower portion 
of the aquifer, remain in the lower portion of the aquifer, with 
ultimate discharge into the Quinnipiac River Basin west-northwest of 
the Site. The also determined that non-VOC COCs from the Site in 
groundwater do not exceed applicable regulatory criteria. Based on the 
SGI's hydraulic studies, it was determined that contaminated 
groundwater underlying the landfill does not discharge into Black Pond 
or the unnamed stream and wetlands.
    Confirmation of the passive landfill gas collection system's 
effectiveness was conducted through several means. After the gas 
collection system was installed and the landfill was capped, three 
rounds of seasonal vapor data were collected directly from the landfill 
gas vents and a risk assessment was conducted. The data results 
indicated that the gas vents were operating effectively and there was 
no risk found to human health or to the environment.
    As part of the 2010 Five-Year Review, a helium tracer study was 
conducted in the northern part of the landfill to simulate potential 
landfill gas migration, low levels of helium were detected outside the 
landfill. Therefore, as a precautionary measure, the PSDs installed an 
impermeable vertical gas barrier trench that extends into the water 
table just outside the landfill cap to prevent possible landfill gas 
from migrating off-Site to the northern neighborhood. The PSDs 
performed a similar evaluation of the gas vents data in the southern 
portion of the landfill and found no risk being posed to human health 
or the environment. All vents continue to be periodically checked 
through long-term monitoring (LTM) and O&M programs.
2. 2006 ROD Findings & Remedial Activities
    This ROD memorialized the remedy to reduce potential risks from the 
migration of volatile contaminants to indoor air within buildings 
located above groundwater contamination. The components of this remedy 
complement those in the1994 ROD.
    The major components of the 2006 ROD are as follows:
    i. Institutional controls, in the form of Environmental Land Use 
Restrictions (ELURs) as defined in Connecticut's Remediation Standard 
Regulations (CT RSRs) will be placed on properties or portions of 
properties where groundwater Volatile Organic Compound (VOC) 
concentrations exceed the CT RSR volatilization criteria for 
residential or commercial/industrial use, or criteria listed in Table 
L-1 of the 2006 ROD. Periodic inspections are required to ensure 
compliance with the institutional controls and to ensure proper 
notification to EPA and the State, as necessary.
    ii. Building ventilation (sub-slab depressurization systems or 
similar technology) will be used in existing buildings located over 
portions of properties where VOCs in groundwater exceed the CT RSR's 
volatilization criteria or criteria listed in Table L-1 of the 2006 ROD 
to prevent migration of VOC vapors into buildings. Similarly, vapor 
barriers (or similar technology) or sub-slab depressurization (or 
similar technology) will be used to control vapors in new buildings.
    iii. Groundwater monitoring will be conducted in areas where the 
potential for vapor intrusion is a concern. Such areas include, but are 
not limited to, the two parcels that are the initial focus of this 
remedial action Chuck & Eddy's (C&E) and the Radio Station. Compliance 
wells will be installed at appropriate locations, to collect 
groundwater to evaluate long-term fluctuations in accordance with the 
monitoring requirements of the CT RSRs and other federal requirements 
to ensure the protectiveness of the remedy in the future.
    iv. Conduct operation, maintenance, and monitoring of engineering 
and institutional controls to ensure remedial measures are performing 
as intended and continue to protect human health and the environment in 
the long-term.
    v. Five-year reviews.
    The 2006 ROD addresses the threat presented by vapor intrusion 
through engineering controls, institutional controls, long-term 
monitoring, and Five-Year Reviews to prevent potential exposure to 
contamination that presents an unacceptable risk to human health. 
Engineering controls (i.e., vapor mitigation systems) will only be 
installed in the future if criteria listed in Table L-1 of the 2006 ROD 
are exceeded and/or if new buildings are constructed on properties of 
concern.
    In August 2010 further testing was performed at the Highland Hills 
neighborhood and the results confirmed that there is no vapor intrusion 
risk to this neighborhood and thus no further action is necessary in 
this area. To confirm that any groundwater contamination that far from 
the landfill edge would be at depths greater than 15 feet and not pose 
a vapor intrusion risk, groundwater samples were collected sequentially 
in discrete vertical intervals and analyzed and compared to criteria 
presented in Table L-1 of the 2006 ROD. Groundwater samples from two 
consecutive 1 foot intervals and subsequently every 5 feet down to 60 
feet were collected and analyzed. There were no exceedances of any of 
the volatilization criteria in the upper 30 feet of the aquifer. These 
results confirm the conceptual Site model that there is no vapor 
intrusion pathway in groundwater below the Highland Hills subdivision 
and therefore no vapor intrusion risk.
    An investigation was conducted by the PSDs with EPA oversight in 
2011 to confirm that the Site's groundwater plume was not migrating 
towards the portion of the aquifer classified by the State as GA 
[potable], situated to the south and southwest of the landfill. The 
investigation results demonstrated that the groundwater that is moving 
through the Landfill moves in a west/northwest direction, which 
continues to support the conceptual Site model for groundwater flow and 
contaminant transport. Thus, the Site groundwater plume does not flow 
toward or impact the GA aquifer. A more detailed description of this 
investigation and findings can be found in the GA Boundary 
Investigation Report (LEA, September 2011).
    A Vapor Intrusion Groundwater Investigation was performed by the 
PSDs during 2011 to assess the potential for vapor intrusion at the 
C&E's Property, the Radio Station Property, and at two locations along 
Nunzio Drive and Barbara Lane (located southwest of the Site). Soil 
boreholes were advanced at select locations and monitoring wells were 
installed. Soil and groundwater samples were collected from these 
locations for analysis. Soil vapor probes were installed in occupied 
structures at the C&E's Property and the Radio Station Property. Four 
quarterly rounds of soil vapor and groundwater samples were collected 
from June 2010 through September 2011. Only vinyl chloride was 
identified as slightly exceeding the criteria presented in Table L-1 of 
the 2006 ROD. No VOCs were detected at concentrations exceeding the 
State RSRs for soil vapor (LEA, 2014). Therefore, construction of 
remedial vapor mitigation systems for existing structures at the C&E's 
Property and the Radio Station Property identified in the 2006 ROD was 
unnecessary. However, a

[[Page 34518]]

passive vapor barrier was installed under the concrete slab for a new 
structure built in 2010 at the C&E's Property.
    Residents and businesses have been permanently relocated from the 
landfill. The landfill has been properly capped and a soil gas 
collection system and impermeable gas barrier have been installed at 
the landfill. Therefore, there is no risk to human health or the 
environment from coming in contact with the landfill soil or landfill 
gas. In addition, everyone who lives or works in the area over the 
groundwater plume is connected to a municipal water supply, and so 
there is no ingestion or dermal contact with the contaminated 
groundwater. The route of potential exposure to human health is through 
vapor intrusion in the shallow groundwater that could potentially 
migrate into buildings. The 2006 remedy addresses this issue through 
long-term monitoring and implementation of vapor intrusion engineering 
controls and institutional controls. The components of 1994 and the 
2006 remedies are functioning effectively as designed.

Cleanup Levels

    Attainment of Groundwater Restoration Cleanup Levels is not a 
Remedial Action Objective at this Site. The final groundwater remedy is 
not designed to clean up or restore groundwater but to address 
potential risks from vapor intrusion into buildings located above 
shallow groundwater contaminated from the Site (EPA, 2006).

Operation and Maintenance

    There is an ongoing O&M program instituted for the 1994 remedy that 
includes landfill cover maintenance, cap effectiveness monitoring 
(groundwater monitoring and gas vent monitoring), and landfill 
inspection. An Operation and Maintenance Plan was prepared in 2001 that 
details the inspections, maintenance, and monitoring activities (CRA, 
2001). An inspection plan was developed to ensure integrity of the 
cover system. Routine inspections of the Site include observing and 
recording the height of grass cover and areas of settlement and/or 
ponding. A security inspection that includes a fence perimeter 
inspection and a visual inspection of trespasser or disturbance 
activity is also conducted periodically. The PSDs' contractor performs 
the cap effectiveness monitoring, inspections, non-routine maintenance. 
One PSD (Town of Southington) performs the soil cover maintenance on a 
routine basis (removal of debris and grass cutting).
    For the 2006 remedy, it was determined that no sub-slab vapor 
mitigation system was required for either the existing C&E property or 
the Radio Station buildings. However, as a preventative measure any new 
construction of new buildings or additions to existing buildings would 
require sub-slab and/or engineering vapor intrusion mitigation 
measures. In 2010, a pre-fabricated building was constructed at the C&E 
property with the placement of a passive vapor barrier. This barrier 
was installed under the direction of the C&E property owner without EPA 
or CT DEEP oversight. As a result, in 2011 a second geomembrane was 
proposed for installation under the concrete slab as a passive vapor 
intrusion barrier. EPA and CT DEEP reviewed and approved the design. 
The installation with oversight, was approved by EPA and CT DEEP. A 
Vapor Intrusion Inspection Plan (VIIP) was developed by LEA in March 
2018 that specifies inspection frequency on a biennial basis with 
mitigation steps as necessary. The VIIP is included in Appendix N of 
the Remedial Action Completion Report (LEA, 2018).
Institutional Controls Implemented
    Institutional controls have been implemented for properties that 
comprise the Site and two properties located downgradient of the capped 
landfill to prevent consumption of groundwater, prevent activities that 
would compromise the integrity of the landfill cap, and restrict 
construction of structures over contaminated groundwater that exceed 
state groundwater standards with regard to preventing vapor intrusion 
exposures. These institutional controls address the requirements of 
both the 1994 and 2006 RODs. The institutional controls are 
environmental restrictions in the forms of ``Declarations of Land Use 
Restrictive Covenants or ``Declarations of Environmental Land Use 
Restrictions (ELURs)''.
    The September 14, 2010 ELURs were executed by the Town of 
Southington for the three Town-owned parcels located in the northern 
area of the capped landfill. In the ELURs, the Town agreed to: (1) 
Place notice of the restrictions on the deed, title, or other 
instrument and have it continue into perpetuity; (2) prohibit any use 
of any portion of the property that will disturb any of the remedial 
measures (except for maintenance and repair upon prior approval by 
EPA); (3) prohibit any activities that could result in exposure to 
contaminants in the subsurface soils and groundwater; (4) prohibit any 
future residential and commercial development on the property; (5) 
prohibit use or consumption of contaminated groundwater underlying the 
property; and (6) grant access to EPA, including its contractors, and 
the State for the purpose of conducting any activity related to the 
CDs. Finally, EPA, the State, and/or the PSDs have the right to enforce 
the ELURs. The April 9, 2018 ELURs were implemented for one Town-owned 
parcel located in the southern area of the capped landfill, which has 
the same restrictions as the September 14, 2010 ELURs.
    In September 17, 2015 ELURs were implemented by the CT DEEP for the 
remaining 9 state-owned parcels of the landfill. These ELURs have the 
same six restrictions as those described in the September 14, 2010 
ELURs, plus an additional restriction that requires any new structure 
to be constructed in accordance to a plan approved by EPA that 
minimizes the risk of inhalation of contaminants. In addition, this 
ELUR indicates EPA and/or the PSDs have the right to enforce the 
restriction.
    The April 19, 2017 ELUR was recorded by the owners of the Radio 
Station Property. In this ELUR, the owners agreed to: (1) Restrict the 
construction of a building over groundwater at the Subject Area where 
volatile organic compounds concentrations exceed the RCSA Section 22a-
133k-1(75) Volatilization Criteria (unless a release is obtained from 
the CT DEEP); (2) allow no action or inaction which would allow a risk 
of pollutant migration, or potential hazard to human health or the 
environment; or result in the disturbance of structural integrity of 
engineering controls used to contain pollutants or limit human 
exposure; (3) in the event of an emergency, notify the CT DEEP, 
implement measures to limit actual or potential risks to human health 
and the environment, implement a plan to ensure restoration of the 
property to conditions prior to the emergency; (4) not allow 
alterations to the property inconsistent with the ELUR until a release 
is approved by the CT DEEP; (5) allows access to the CT DEEP agents 
that perform pollution remediation activities; (6) allow access onto 
the property by the CT DEEP upon reasonable notice; and (7) require the 
property owner to notify any future interests of the ELUR requirements. 
This ELUR is enforceable by the CT DEEP.
    The June 22, 2017 Declaration of ELUR was recorded by the owner of 
the property where the C&E's Used Auto Parts business is located. This 
ELUR has the same seven restrictions as described in the April 2017 
ELUR.

[[Page 34519]]

Five-Year Review

    Hazardous substances will remain at the Site above levels that 
allow unlimited use and unrestricted exposure after the completion of 
the action. Pursuant to CERCLA Sec.  121(c) and as provided in the 
current guidance on Five-Year Reviews (OSWER Directive 9355.7-03B-P, 
June 2001), EPA must conduct statutorily required Five-Year Reviews. 
The first Five-Year Review was conducted in September 2005. The second 
and third Five-Year Reviews were completed in September 2010 and in 
September, 2015, respectively. The September 2015 Five-Year Review 
found the Site remedy currently protective of human health and the 
environment. There was one issue and recommendation, to complete the 
Institutional Controls at the C&E property and the Radio Station 
Property. The PSDs continued to work collaboratively with CT DEEP and 
the property owners at these two properties and in June 2017 
institutional controls, in the form of ELURs, were finalized. These 
actions completed the 2015 Five-Year Review recommendation. The remedy 
is protective of human health and the environment. The next Five-Year 
Review is scheduled for September 2020.

Community Involvement

    From approximately 1988 through 2002, community concern and 
involvement was high at this Site. EPA kept the community and other 
interested parties apprised of the Site's activities through 
informational meetings, fact sheets, press releases and public 
meetings. In October 1988, EPA released a community relations plan that 
outlined a program to address community concerns to keep citizens 
informed and involved with remedial activities. On December 14, 1988, 
EPA held an informational meeting in the Southington Public Library to 
describe the plans for the Remedial Investigation and Feasibility 
Study. In January 1993, a $50,000 technical assistance grant was 
awarded by EPA to a local group of citizens who called themselves, 
Southington of Landfill Victims, (SOLV) to hire a technical consultant 
to help them better understand the Site's technical data and 
information. This consultant provided the group technical assistance in 
interpreting technical documents relating to the remedial 
investigation, human and ecological risk assessments, remedial design, 
and remedial action. On May 23, 1994, EPA completed the administrative 
record which included documents that were used by EPA to propose the 
remedy for the Site. These documents were available for public review 
at EPA's offices in Boston, Massachusetts and at the Site Repository at 
the Southington Public Library, Southington, CT.
    The Proposed Plan was made available to the public on May 23, 1994. 
On June 14, 1994, EPA held a public meeting to discuss the results of 
the Remedial Investigation, the cleanup activities presented in the FS 
and to present the Agency's Proposed Plan. This was followed by a 30-
day comment period. On June 29, 1994 residents requested an additional 
30-day comment period to August 13, 1994, which was granted by EPA.
    On July 12, 1994, the Agency held a public hearing to discuss the 
Proposed Plan and to accept oral comments. A transcript of this hearing 
and comments, along with the Agency's response to comments are included 
in the Responsiveness Summary found in Appendix A of the 1994 ROD.
    In June 2006 EPA issued a second Proposed Plan with a 60-day 
comment period from June 22, 2006 through August 24, 2006 for the final 
remedy to address vapor intrusion at properties downgradient of the 
landfill. On July 6, 2006 a public hearing was conducted to accept 
verbal comments. All comments were addressed in the responsiveness 
summary included in PART 3 of the 2006 ROD.
    After the 1994 ROD remedy was implemented, community involvement 
and interest decreased significantly. EPA continues to conduct 
community outreach through its Five-Year Reviews or any time there is 
new information to share with the public.
    EPA has worked closely with CT DEEP and the PSDs throughout the 
preparation of documentation for the deletion process. The community is 
being notified of EPA's intent to delete the Site from the NPL through 
the publication of this Notice of Intent to Delete and the public will 
be provided with a 30-day comment period. EPA will take all of received 
comments into consideration and in consultation with CT DEEP, and will 
respond, as appropriate, to the comments in a responsiveness summary.

Determination That the Site Meets the Criteria for Deletion in the NCP

    All Remedial Design and Remedial Action (RD/RA) activities at the 
Site were consistent with the 1994 ROD, the 2006 ROD, as well as all 
respective EPA Statements of Work provided by the PSDs. All selected 
remedial and removal action objectives and associated cleanup levels 
are consistent with agency policy and guidance. RA plans for all phases 
of construction included Quality Assurance Project Plans (QAPPs) which 
incorporated all EPA quality assurance and quality control procedures 
and protocols (where necessary). All procedures and protocols were 
followed for soil, groundwater, surface water, sediment, soil gas, and 
fish tissue sampling. EPA analytical methods were used for all 
validation and monitoring during all RA activities. EPA has determined 
that the analytical results were accurate to the degree needed to 
assure satisfactory execution of the RAs, and were consistent with the 
RODs and RD/RA plans and specifications.
    All Institutional Controls are in place and currently EPA expects 
that no further Superfund response is needed to protect human health 
and the environment, other than future Five-Year Reviews, ongoing long-
term monitoring, O&M, and inspections. Confirmatory groundwater 
monitoring and institutional controls provide further assurance that 
the Site no longer poses any threats to human health or the 
environment. Operation and maintenance activities were agreed upon by 
EPA, in consultation with CT DEEP, and the PSDs in the 2001 O&M Plan 
and the 2018 Vapor Intrusion Monitoring Plan (VIIP).
    EPA has followed the procedures required by 40 CFR 300.425(e). The 
Site meets all Site completion requirements as specified in OSWER 
Directive 9320.2-09-A-P, Close Out Procedures for National Priorities 
List Sites. All cleanup actions specified in the 1994 and 2006 RODs 
have been achieved for all pathways of exposure. Therefore, no further 
Superfund response is needed to protect human health and the 
environment.
    A bibliography of all reports relevant to the completion of this 
Site under the Superfund program are included in the administrative 
record for this deletion.

List of Subjects in 40 CFR Part 300

    Environmental protection, Air pollution control, Chemicals, 
Hazardous waste, Hazardous substances, Intergovernmental relations, 
Penalties, Reporting and recordkeeping requirements, Superfund, Water 
pollution control, and Water supply.

    Authority: 33 U.S.C. 1321(d); 42 U.S.C. 9601-9657; E.O. 13626, 
77 FR 56749, 3 CFR, 2013 Comp., p. 306; E.O. 12777, 56 FR 54757, 3 
CFR, 1991 Comp., p. 351; E.O. 12580, 52 FR 2923, 3 CFR, 1987 Comp., 
p. 193.


[[Page 34520]]


    Dated: July 9, 2018.
Alexandra Dunn,
Regional Administrator Region 1.
[FR Doc. 2018-15628 Filed 7-19-18; 8:45 am]
BILLING CODE 6560-50-P