| Site Type: Long Term/National Priorities List (NPL) |
NEW LONDON SUBMARINE BASE
Map this site in Cleanups in My Community
| Groton and Ledyard,  Connecticut|
| New London County
| Street Address: ||Route 12 Crystal Lake Road |
| Zip Code: || 06349 |
| Congressional |
| EPA ID #: ||CTD980906515 |
| Site ID #: ||0100261 |
| Site Aliases: ||DOD/USN SB/Overbank Disp Area NW 3 DOD/USN SB/DPDO, Area Site #6, DOD/USN SB/Area A Landfill #2|
| Site Responsibility: ||Federal |
| NPL LISTING HISTORY |
| Proposed Date ||10/26/1989|
| Final Date ||08/03/1990 |
The New London Submarine Base site covers 576 acres on the eastern bank of the Thames River in Groton. The base was established in 1868, and has been an operation and support base for submarine activities in the Atlantic Ocean since 1916. Areas of concern include the Area A Landfill, the Over Bank Disposal Area, the Defense Reutilization and Marketing Office (DRMO), the Lower Submarine Base, and the Goss Cove Landfill. From 1957 to 1973, volatile organic compounds (VOCs), pesticides, polychlorinated biphenyls (PCBs), spent battery acids, and other wastes were buried below the water table in the 11-acre Area A Landfill, which is situated adjacent to wetlands. The Over Bank Disposal Area was created sometime after an earthen dam was built in 1957. The DRMO was used as a burning ground and landfill from 1950 to 1969 and is currently used as a temporary storage area. Inspection reports from 1982 recorded leaking containers and evidence of spills associated with containers stored directly on the ground. In 1983, approximately 40 gallons of PCB-contaminated oil were reported to have been spilled onto the ground. In 1988, Navy sampling revealed lead, cadmium, and various pesticides in sediments and surface water. The area around the base is mixed industrial, commercial, and residential property. Groundwater in some areas of the base is as shallow as 8 feet below the surface, with permeable soils. These conditions potentially threaten the area groundwater. The population within 1 mile of the base is 4,000.
Threats and Contaminants
The soil, sediments, groundwater, and surface water are contaminated with pesticides and heavy metals including cadmium and lead. The soil also contains VOCs, PCBs, and polycyclic aromatic hydrocarbons (PAHs). The site is a restricted-access Naval base, so the chance of direct contact with on-site sediments, soil, or surface water is minimal.
The site is being addressed in five long-term remedial phases focusing on cleanup of the Area A Landfill, the Over Bank Disposal Area, the DRMO Area, the Lower Sub Base, and other contaminated areas of the base.
Response Action Status
|Area A Landfill ||In 1990, the Navy began an investigation into the nature and extent of VOC, pesticide, battery acid, and other contamination at the Area A Landfill. While in operation, the landfill accepted all non-salvageable materials. Leachate from the landfill drains into the area wetland and is ultimately carried downstream and discharged into the Thames River. At the conclusion of the investigation, completed in the fall of 1995, a final cleanup remedy was selected that includes installation of a double-lined landfill cap and monitoring. Design and construction of the selected remedy were completed in October 1997. Before construction, a removal action was completed at the CBU Drum Storage Area located on top of the landfill. |
|Area A Downstream/Over Bank Disposal Area ||In 1990, the Navy began an investigation into the nature and extent of contamination at the Over Bank Disposal Area. The Navy removed all contaminated soils and debris at the Over Bank Disposal Area as part of an interim cleanup action in March 1997. A Record of Decision (ROD) was signed on March 30, 1998 that requires excavation and dredging of contaminated soils and sediments. Construction and wetland restoration is complete. A Record of Decision was signed in November 2004 for remediation of petroleum related compounds discovered at the new source area. An ESD was completed in June 2007 that documented the need for ICs and 5 year reviews because some waste was left in place. Construction is completed. |
|DRMO Area ||In 1990, the Navy began a study into the nature and extent of contamination at the DRMO Area. Initial findings detected high to moderate levels of contaminants in the soil samples analyzed; low contaminant levels were detected in the groundwater. The second phase of this investigation is currently underway. Upon completion of the investigation, scheduled for early 1998, a final cleanup remedy will be selected. In November 1994, as an interim cleanup remedy, the Navy removed soil contaminated with PCB and lead, backfilled the area with clean fill, and placed an asphalt cap over the area. The removal action will be evaluated for its long-term effectiveness by groundwater monitoring. A ROD was signed on March 30, 1998. The remedies selected were institutional controls to prevent digging, disturbance of the existing cap and other exposure as well as groundwater monitoring to ensure that contaminants do not migrate to the Thames River. A final ROD for the site was signed in December 2006. The ICs required for this site (and the rest of the base) are documented in Appendix E to this ROD. Construction is completed. |
|Lower Sub Base ||In 1990, the Navy began an investigation into the nature and extent of contamination at the Lower Sub Base. Petroleum products have been observed in several man holes. The exact source of these releases is still being investigated, although it appears to be from underground fuel lines or storage tank leaks. At the conclusion of the investigation, scheduled for 2005, a final cleanup remedy will be selected. As part of an interim cleanup action in July 1994, the Navy removed lead-contaminated soil from the Building 31 area, disposed it off site, and backfilled the area with clean fill. A draft final FS is currently planned to be issued in September 2009. A ROD was signed in August 2012, which is expected to be the last remedy for the base. In January 2010, the Navy dredged contaminated sediments near Pier 1 in the former marine railway. Additional dredging wasconducted in early 2013 to complete this action. Construction is currently underway for the soil and sediment dredging will begin in 2015. |
|Goss Cove Landfill ||In 1990, the Navy began an investigation into the nature and extent of contamination. A Record of Decision was signed in September 1999 that called for a semi permeable cap with groundwater monitoring. Construction of the remedy was completed in October 2001. |
|Area A Weapons Center ||In 1990, the Navy began an investigation into the nature and extent of contamination. A Record of Decision was signed in June 2000. Construction of the remedy began in September 2001 and was completed by the end of December 2001. |
|Other Areas ||In 1993, the Navy began an investigation into the nature and extent of contamination in other site areas. The site areas being investigated include: Lower Submarine Base and a Former Gasoline Station. Once the investigations are completed, the EPA and the State will evaluate the study results to determine the most appropriate cleanup remedies. |
|Torpedo Shops ||A ROD was signed in September 2004 that called for excavation with off-site disposal. Approximately 1,600 cubic yards of soil will be removed and the total cost is estimated to be $440,200. The following remediation goals have been established: PAHs, 1 mg/kg; benzene, 0.02 mg/kg; chlorobenzene, 2 mg/kg; and 1,4-dichlorobenzene, 1.5 mg/kg.|
No further action under CERCLA was recommended for Site 14 because a removal action in 2001 addressed all incremental cancer risks and hazard indices (now within or below EPA’s acceptable risk ranges).
|Basewide Groundwater ||An interim ROD for groundwater in the northern portion of the Site was signed in December 2004. The groundwater at Sites 3, 7, 14, 15, 18, and 20 comprises only a portion of the basewide groundwater Operable Unit (OU9). A Final action for OU9 will be selected after the remaining sites have been investigated and when source control actions are complete (2008).|
Institutional controls that restrict extraction and use of the groundwater were implemented at Sites 3 (Area A Downstream Watercourses) and 7 (Torpedo Shops) in December 2006. The location and magnitude of the groundwater contamination will also be identified. No further action under CERCLA is recommended for the groundwater at Sites 14 (Overbank Disposal Area Northeast), 15 (Spent Acid Storage and Disposal Area), 18 (Solvent Storage Area), and 20 (Area A Weapons Center) because all incremental cancer risks and hazard indices are within or below EPA’s acceptable risk ranges.
|Sites 16 & 18 ||Site 16 comprises the two areas located west of Tautog Road, adjacent to Buildings 449 and 452 near the Naval Hospital in Groton, CT. The Naval Hospital operated a skid-mounted waste incinerator adjacent to the hospital in the 1980s. The incinerator was used to destroy medical records and medical waste contaminated with pathological agents.|
Site 18 consists of Building 33, the Solvent Storage Area, and was used for the storage of gas cylinders and 55-gallon drums of solvents such as trichloroethene and dichloroethene.
No further action under CERCLA was selected in September 2004 because all incremental cancer risks and hazard indices are within or below EPA’s acceptable risk ranges.
|Area A Wetland ||The Area A Wetland was created in the 1950s by dumping sediments dredged from the Thames River into a wooded area. Investigations occurred in March 1997 and November 2008. Limited hot spots were revealed. An RI supplement and FS is planned to be issued in November 2009. In 2010, the Navy and CTDEEP conducted extensive Phragmites control within the wetland. A ROD was signed in August 2010 that requires excavation of contaminated sediments and restoration of native wetland vegetation. Remedial Action is completed and the Navy is monitoring invasive species.|
|Enforcement Highlights||The base is participating in the Installation Restoration Program, a specially funded program established by the Department of Defense (DOD) in 1978 to identify, investigate, and control the migration of hazardous contaminants at military and other DOD facilities. |
The removal of PCB- and lead-contaminated soil and the capping of the DRMO area, Building 31, and the Spent Acid Storage Disposal Area have reduced threats at the New London Submarine Base site while investigations of other site areas are underway. Removal actions were completed in March 1997 at OBDA and the Rubble Fill Area at Bunker A-86. The Area A Landfill, Goss Cove landfill, and DRMO caps are all also completed. A ROD was signed for the Rubble Fill Area at Bunker A-86 in June 1998. Excavation work has been completed at the Area A Downstream. A removal action was completed at the Over the Bank Disposal Area Northeast in 2001. Construction is complete at the Area A Weapons Center. Preparations for deletion from the NPL will begin after the final remedy selections for the Lower Submarine Base and the Area A Wetland are in place.
Current Site Status
The Naval Submarine Base encompasses 547 acres adjacent to the Thames River in Groton, CT. The site contains multiple areas of contamination, including three landfills, chemical storage sites, tank farms, contaminated watercourses, and varying degrees of groundwater contamination. The U.S. Navy is the lead agency for site investigation and cleanup, with formal oversight by EPA via a federal facilities agreement (FFA) and the Connecticut Department of Environmental Protection.
There has been substantial environmental progress at the Naval Submarine Base. All three of the landfills have been capped (Area A, DRMO, and Goss Cove), 7 removal actions have been completed (Building 31, Spent Acid Storage and Disposal Area, DRMO, Rubble Fill at Bunker A-86, CBU Drum Storage Area, OBDA, and OBDANE), and contaminated soil/sediment at the Area A Downstream has been removed. Wetland restoration is completed at the Area A Downstream. Soil excavation was completed at the Area A Weapons Center in December 2001. Investigations are well underway at the Lower Sub base Area and for the groundwater throughout the base. The first Five Year Review was completed in December 2001 and the second and third Five Year Reviews were completed in December 2006 and December 2011, respectively.
Links to Other Site Information
Maps and Photos:
Newsletters & Press Releases:
Federal Register Notices:
Reports and Studies:
|First Five-Year Review Report, December 7, 2001 (162KB)   |
|Proposed Plan for Site 3 - New Source Area Soil (Operable Unit 03) July 2004 (504KB)   |
|Proposed Plan for Site 7 - Torpedo Shops, and Site 14 - Overbank Disposal Area Northeast Soil (Operable Unit 08) July 2004 (467KB)   |
|Proposed Plan for Site 16 - Hospital Incinerators and Site 18 - Solvent Storage Area Soil (Operable Unit 11) July 2004 (311KB)   |
|Proposed Plan for the Groundwater at Sites 3, 7, 14, 15, 18, and 20 (Operable Unit 9), September 2004 (2,617KB)   |
|Second Five-Year Review, December 21, 2006 (30.89 MB with link to external PDF file)   |
|Proposed Plan for Sediment at Area A Wetland, Site 2B, (Operable Unit 12), June 01, 2010 (1.16 MB)    |
|Third Five-Year Review Report, December 1, 2011 (49.5 MB)   |
|Proposed Plan for Lower Subase (Operable Unit 4), March 1, 2012 (6.91 MB)   |
|View Records of Decision (RODS) on-line (EPA HQ)   |
|Record of Decision for Site 7 - Torpedo Shops and Site 14 - Overbank Disposal Area Northeast Soil, Operable Unit 08, September 30, 2004 (5,35MB)   |
|Record of Decision for Site 16 and 18 Soil, Operable Unit 11, September 30, 2004 (4,984KB)   |
|Record of Decision for Site 3 - New Source Area Soil, Operable Unit 03, November 9, 2004 (2,398KB)   |
|Interim Record of Decision for Sites 3, 7, 14, 15, 18, and 20 - Groundwater, Operable Unit 09, December 30, 2004 (four linked files; opening file 1,118KB)    |
|Record of Decision for Site 6 Soil and Groundwater, December 20, 2006 (18.7 MB)   |
|Explanation of Significant Difference (ESD) for the Record of Decision (ROD), Operable Unit 3, May 5, 2007 (1.01 MB)   |
|Record of Decision for Operable Unit 9, Basewide Groundwater, September 30, 2008 (Opening file is 30.6 MB with link to external PDF file)   |
|Record of Decision (ROD) for Operable Unit 12, Site 2B - Area A Wetland, September 2, 2010 (9.62 MB)   |
|Record of Decision (ROD) for Operable Unit 4, Lower Subase Zones 1 through 7, Sites 10, 11, 13, 17, 19, 21, 22, 24 and 25, August 23, 2012 (34.9 MB)   |
Town of Groton Public Library, 52 Route 117 Newtown Rd., Groton, CT 06340
Bill Library, 718 Colonel Ledyard Highway, Ledyard, CT 06339
Public Works Office, Naval Submarine Base, New London, Groton, CT 06349
|EPA Remedial Project Manager: ||Kymberlee Keckler |
|Address: ||US Environmental Protection Agency|
5 Post Office Square, Suite 100
Mail Code: OSRR07-3
Boston, MA 02109-3912
|Phone #: ||617-918-1385 |
|E-Mail Address: ||firstname.lastname@example.org |
|EPA Community Involvement Coordinator: ||Sarah White |
|Address: ||US Environmental Protection Agency|
5 Post Office Square, Suite 100
Mail Code: ORA20-1
Boston, MA 02109-3912
|Phone #: ||617-918-1026 |
|E-Mail Address: ||email@example.com |