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Waste Site Cleanup & Reuse in New England
  Serving Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont & 9 Tribal Nations
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 Site Type: Long Term/National Priorities List (NPL) Click to see more about Site Type and how it is used?


Map this site in Cleanups in My Community
 Winthrop,  Maine
 Kennebec County
 Zip Code: 04364

 EPA ID #: MED980504435
 Site ID #: 0101012
 Site Aliases:

 Site Responsibility: Federal, Municipal, Potentially Responsible Parties

 Proposed Date 10/23/1981
 Final Date 09/08/1983

Site Description
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The Winthrop Landfill is a 13-acre site located next to Lake Annabessacook and consists of two adjacent properties, the Winthrop Town Landfill and the privately owned Savage Landfill. The site initially was used in the 1920s as a sand and gravel pit. In the 1930s, parts of the site received municipal, commercial, and industrial wastes. The site accepted hazardous substances between the early 1950s and mid-1970s. It is estimated that more than 3 million gallons of chemical wastes, mostly complex organic compounds including resins, plasticizers, solvents, and other process chemicals, were disposed of at the site. Late in 1979, the Town attempted to expand the landfill, but this revealed numerous rusting and leaking barrels. The Town decided to close the landfill and construct a transfer station on the site. The Savage Landfill contracted to accept municipal solid waste and debris from two small neighboring towns and also accepted wastes from Winthrop to extend the life of the town landfill. Wastes were openly burned until 1972, and landfilling occurred from 1972 until 1982. There are 63 residences within 1/2 mile of the site. Wetlands are located near the site, and Lake Annabessacook is used for recreational purposes.

Threats and Contaminants
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Volatile organic compounds (VOCs) from the landfill were found to be migrating off site into the groundwater. The soil was contaminated from drums containing inorganic and organic chemicals and municipal wastes. Potential risks exist if contaminated soil or groundwater is accidentally ingested. The area is fenced and capped to protect against direct contact with contamination. Wetlands located near the site are potentially at risk from site contamination.

Cleanup Approach
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The site is being addressed in three stages: immediate actions and two long-term remedial phases focusing on cleanup of the entire site as well as groundwater and surface water.

Response Action Status
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Immediate Actions The potentially responsible parties and the Town of Winthrop extended the municipal water supply to residents previously on well water drawn from a contaminated aquifer below the landfill.

Entire Site An impermeable clay cover was built over the landfill to contain the landfilled wastes, thereby reducing the quantity of contaminated leachate entering the groundwater. A fence was erected around the landfill to protect against direct contact with site contamination. Deed restrictions were imposed prohibiting the use of the landfill for activities other than the cleanup actions, prohibiting excavation in the area of the landfill, and prohibiting groundwater use in the area. Long-term monitoring of groundwater, surface water, and sediments is ongoing on a quarterly basis to ensure the effectiveness of the clay cover.

Groundwater and Surface Water Treatment The potentially responsible parties installed a vapor extraction and treatment system to remove contamination from the landfill waste to keep it from infiltrating the groundwater. The vapor extraction plant began operating in late 1994. In 1995, the potentially responsible parties began operating a groundwater extraction and treatment system to contain, treat, and eliminate groundwater and surface water contamination. The vapor extraction system reached the limit of effective remediation and was discontinued in 2000. In 2002, the groundwater extraction and treatment system (GWETS) was shut down to allow for a rebound evaluation. In 2007, EPA issued an Explanation of Significant Differences outlining permanent decommissioning of the GWETS and a requirement to monitor, evaluate, and if warranted, remediate, contaminants at points of exposure. The GWETS has since been removed, and the Town of Winthrop accepted ownership of the treatment buildings in October 2008.

Enforcement HighlightsA Consent Decree ordering the potentially responsible parties to perform the above actions was signed by the EPA and the parties and filed with the U.S. District Court in 1986.

Environmental Progress
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Provision of an alternative water supply to affected residences, installation of a fence to restrict site access, construction of a clay cap over landfill wastes, and operation of a vapor extraction system and a groundwater extraction and treatment system to reduce contamination within the landfill is preventing further migration of contaminants into the groundwater and reduced the threat of direct contact with contaminants at the Winthrop Landfill site while remaining cleanup actions are underway. EPA issued an Explanation of Significant Differences (ESD) in 2007 allowing for the decommissioning of the groundwater extraction and treatment system, and requiring monitoring, evaluation, and if warranted, remediation of contaminants at points of exposure.

Current Site Status
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A cap has been placed over the former industrial waste landfill. The soil vapor extraction system began operation in 1994 while the groundwater pump and treatment began in 1995. The oversight of the treatment systems is ongoing. A public meeting was held at the site on August 21, 2002, to discuss a proposed conceptual rebound evaluation for the groundwater extraction and treatment system; this evaluation will study the water levels and chemistry of groundwater as it responds to unstressed conditions while the system is shut down. EPA and the Maine Department of Environmental Protection approved a work plan to implement this plan, and the treatment system was shut down on November 19, 2002.

At the end of the evaluation, EPA and ME DEP determined that continued operation of the groundwater extraction and treatment system (GWETS) was no longer effective in reducing levels of arsenic, the only remaining groundwater contaminant that remains significantly above cleanup levels. In August 2006, EPA released a draft Explanation of Significant Differences (ESD) for public review and comment, and conducted a public meeting on August 28, 2006 to outline the ESD. EPA finalized the ESD in February 2007. The ESD allows for decommissioning of the GWETS, and provides additional measures to monitor, evaluate, and if necessary, remediate contaminants that may pose an unacceptable risk. In November 2007, EPA and ME DEP approved a GWETS Decommissioning and Equipment Removal Plan. Major equipment removal began in mid-December, and all equipment removal work was completed by March 2008. In October 2008, the Town of Winthrop accepted ownership of the treatment plant buildings from United Technologies Corporation.

In 2009-2011, EPA, ME DEP, and the responsible parties continued to develop plans to monitor and evaluate human health and ecological risk at the two major points of exposure, the Annabessacook Lake Seep Area and the Hoyt Brook Seep Area, and to also evaluate the implementability of remedial technologies at the Hoyt Brook Seep Area. Sampling at the lake and brook areas continues through the present. Sampling efforts include surface water, sediment and algae/flocculent sampling at the Annabessacook Lake Seep Area and/or the Hoyt Brook Seep Area.

Site Photos
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Links to Other Site Information
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Disclaimer Instructions about PDF

Newsletters & Press Releases:
Press Release about this project  
Community Update: Groundwater Treatment Plant Being Decommissioned and New Location for Public Information Repository, December 1, 2007 (122.36 KB)  
Community Update, July 2015  

Federal Register Notices:
Final NPL Listing  

Administrative Records:
Index Only: Administrative Record, Explanation of Significant Differences (ESD), February 14, 2007 (468 KB)  

Reports and Studies:
Preliminary Close Out Report (PCOR), September 1, 1997 (543.6 KB)  
Second Five Year Review Report, September 30, 1997 (208KB)  
Construction Completion Memorandum, December 16, 1997 (59.93 KB)  
Preliminary Close Out Report (PCOR) Amendment Page, December 23, 1997 (76.81 KB)  
Third Five Year Review Report, September 30, 2002  
Fourth Five Year Review Report, September 21, 2007 (4.92 MB)  
Fifth Five Year Review Report, September 19, 2012 (15.9 MB)  
Final Hoyt Brook Seep Pilot Study Work Plan, August 18, 2015   

Decision Documents:
View Records of Decision (RODS) on-line (EPA HQ)  
Explanation of Significant Differences (ESD), February 14, 2007 (1MB)  
Institutional Controls at this Site  

Other Links:
NPL Site Narrative at Listing:  
Site Progress Profile  

Site Repositories
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The local site repository is currently located at the Winthrop Town Offices at 17 Highland Avenue, Winthrop, ME 04364. Viewing of the repository can be arranged by contacting the Town Manager, Jeff Woolston, at 207-377-7200, ext. 423.

OSRR Records and Information Center, 1st Floor, 5 Post Office Square, Suite 100 (HSC), Boston, MA 02109-3912 (617) 918-1440

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EPA Remedial Project Manager: Terry Connelly
Address: US Environmental Protection Agency
5 Post Office Square, Suite 100
Mail Code: OSRR07-1
Boston, MA 02109-3912
Phone #: 617-918-1373
E-Mail Address: connelly.terry@epa.gov

EPA Community Involvement Coordinator: Pamela Harting-Barrat
Address: US Environmental Protection Agency
5 Post Office Square, Suite 100
Mail Code: ORA20-1
Boston, MA 02109-3912
Phone #: 617-918-1318
E-Mail Address: harting-barrat.pamela@epa.gov

State Agency Contact: Rebecca Hewett
Address: Maine DEP
State House Station 17
Augusta, ME, 04333
Phone #: 207-287-8554
E-Mail Address: rebecca.L.hewett@maine.gov


Serving Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont, & 10 Tribal Nations
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Last updated on Tuesday, November 3rd, 2015
URL: http://www.epa.gov/region1/superfund/sites/winthrop