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Site Type: Long Term/National Priorities List (NPL)  |
SAVAGE MUNICIPAL WATER SUPPLY |
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| Milford, New Hampshire |
Hillsborough County
| Street Address: | NEAR RTE. 101 |
| Zip Code: | 03055 |
Congressional
District(s): |
02 |
| EPA ID #: | NHD980671002 |
| Site ID #: | 0101145 |
| Site Aliases: |
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| Site Responsibility: | Federal, State, Potentially Responsible Parties |
| NPL LISTING HISTORY |
| Proposed Date | 09/08/1983 |
| Final Date | 09/21/1984 |
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Site Description
The Savage Municipal Water Supply site covers approximately 235 acres, is located about 5 miles west of the center of Milford, and consists of a municipal well and the underlying aquifer. The Savage Well operated from 1960 to 1983, during which it supplied approximately 45 percent of Milford's drinking water, averaging about 200,000 gallons per day. The remainder of the Town's water supply was provided by the Keyes and Kokko Wells. Land uses within the site area include residential, agricultural, heavy and light industry, commercial enterprises, and aquaculture. Contamination was first discovered at the site as a result of a State-wide drinking water sampling program in 1983. The Savage Municipal Well and a nearby contaminated well supplying drinking water to a trailer park were later closed. At that time, the State began investigations to locate the source of contaminants that were also present in the wastes of nearby industries. Industry and fish hatcheries also withdraw water from the aquifer. A stream that receives discharge from Hitchiner Manufacturing and previously from Hendrix Wire and Cable flows through the site prior to entering the Souhegan River. Hitchiner Manufacturing has purchased the Savage Municipal Well property from the Town of Milford and also owns 65 acres of farm land which has been protected from development by the purchase of development rights by the NH Department of Agriculture.
Threats and Contaminants
The groundwater is contaminated with volatile organic compounds (VOCs) including tetrachloroethylene (PCE), trichloroethylene (TCE), 111-trichloroethane, and vinyl chloride; and heavy metals including lead, chromium, and nickel. The soil is also contaminated with VOCs. Trespassers who may come into direct contact with or accidentally ingest contaminated soil or groundwater may be at risk.
Cleanup Approach
The site is being addressed in two stages: immediate actions and a long-term remedial phase focusing on cleanup of the entire site.
Response Action Status
| Immediate Actions | In 1983, the EPA provided bottled water to 75 residents at the Milford Mobile Home Park who were affected by contaminated well water in the area. Subsequently, the EPA connected the park to the municipal water supply. |
| Entire Site | The parties potentially responsible for site contamination conducted an investigation into the nature and extent of the contamination. A final cleanup remedy was selected in 1991 that entailed the construction and installation of a groundwater pump and treatment facility. As a result of negotiations, the site was divided into two operable units (OU). OU1 is known as the OK Tool Source Area and OU2 is known as the Extended Plume Area.
In the fall of 1993, under EPA supervision, the state began the design of a slurry wall and pump and treatment system for the OK Tool Source Area. The design was completed in 1996. A contract for the construction was awarded in November 1997. Construction was completed in March 1999.
In the spring of 1994, the potentially responsible parties began designing the pump and treat system for a portion of the Extended Plume Area. A portion of the OU2 area will be left to cleanse itself through natural attenuation. Design of the OU2 remedy was completed in December 2003. Construction of the Extended Plume Remedial Action began in the Spring of 2004 and was completed in the fall of 2004. |
| Water Supply | The critical importance of this aquifer has been highlighted by the recent drought in Southern New Hampshire and the pressure from increasing populations and industrial growth on water resources in Southern New Hampshire. The Milford Souhegan aquifer is highly prolific in terms of water yield. Using water yield as a measure of this aquifers potential, it ranks in the highest 10% for the entire state. The restoration of the aquifer for use as a drinking water supply will ensure self sufficiency for the town of Milford and possibly provide drinking water for regional use. |
| Operable Unit 1 - DNAPL Remediation | EPA and NHDES have been implementing an aggressive program to destroy contamination in the subsurface within the slurry wall. The contamination is in the form of Dense Non-Aqueous Phase Liquid (DNAPL), which means the contamination is not dissolved into the ground water but exists as a free phase product. Using existing wells within the slurry wall, EPA and NHDES have begun in-situ chemical oxidation treatments of this subsurface contamination using potassium permanganate. The permanganate is mixed with water from the treatment plant to a strength of about 2.6% and injected into the ground where it destroys the PCE through an oxidation chemical reaction. The first injection consisted of 8000 pounds of permanganate in September, 2003. A second injection consisted of 24,000 pounds of permanganate in October, 2004. Current groundwater monitoring shows that 17 of 34 monitoring wells outside of the slurry wall are either clean or below the clean up standards for the contaminants of concern. Progress inside the slurry wall continues; however, monitoring continues to identify areas of high contamination which still needs some form of aggressive remediation. |
| Operable Unit 1 - Bioremediation Evaluation | EPA began evaluating the potential for bioremediation of subsurface ground water contamination in 2003. This continued in 2004 and looks promising for use as a polishing step in the future for clean up of the ground water contamination after permanganate injection is completed. As of 2007, it appears that continued aggressive in-situ treatment is still necessary inside the slurry wall. |
| Operable Unit 2 | Operable Unit (OU) 2 is successfully extracting ground water and treating it to remove the contaminants of concern. The treated ground water is either discharged to three injection wells and/or into the Souhegan River depending on the ground water levels in the aquifer. The purpose of injecting the treated ground water into the aquifer is to speed the clean up time of the OU2 remediation. |
| Enforcement Highlights | In 1987, the EPA and the parties potentially responsible for the contamination of the site signed a Consent Order in which the parties agreed to conduct an investigation at the site. Two Consent Decrees were entered in the U. S. District Court of New Hampshire in 1994. The first, entered in June, required the settling potentially responsible parties to clean up the groundwater. The second, entered in December, is for financial assistance from the potentially responsible parties. |
Environmental Progress
Providing bottled water and connecting residents to the municipal water supply reduced the immediate, potential for exposure to hazardous materials at the Savage Municipal Water Supply site. Groundwater cleanup at OU1 is continuing. Operation of the groundwater pump and treatment facilities at OU2 began in late November 2004, were shutdown in December 2004, and were restarted in 2005.
Current Site Status
The slurry wall and groundwater extraction and treatment system for the OK Tool Source Area (i.e., OU1) was completed and placed into operation in 1999. Data shows that there has been significant reductions in groundwater contamination levels within OU1. Injections of potassium permanganate were done in 2003 and 2004 within the slurry wall of OU1. This is an aggressive way to speed up groundwater restoration which began in 1999.
Remediation of Operable Unit 2 (OU2 or the Extended Plume Area) is the responsibility of the several settling parties. The design for clean up of the contaminated groundwater plume in OU2 was completed in December 2003. The design was for a 450 gallon per minute treatment plant using air stripping as the technology to remove the contamination from the ground water. The treated water is to be injected back into the ground to assist in cleaning up the aquifer. A construction contract to build the OU2 treatment facility was awarded in March 2004. Construction was completed in the November 2004. The plant began operation in late November 2004, and was shut down in December 2004 due to problems which caused the injection wells to malfunction. Modifications were constructed in 2005 which included the addition of metals treatment and a surface water outfall to the Souhegan River. Extraction and treatment operations were restarted in 2005 with permanent modifications completed in 2006.
Site Photos
OU 2 Treatment Plant
Links to Other Site Information
Newsletters & Press Releases:
Federal Register Notices:
Administrative Records:
Reports and Studies:
Decision Documents:
Other Links:
Site Repositories
Wadleigh Memorial Library, 21 Nashua Street, Milford, NH 03055
EPA New England Records Center, One Congress Street, Boston, MA 02114 (617) 918-1440
Contacts
| EPA Remedial Project Manager: | Richard Goehlert |
| Address: | |
| Phone #: | (617) 918-1335 |
| E-Mail Address: | goehlert.dick@epa.gov |
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| State Agency Contact: | Thomas Andrews |
| Address: | 29 Hazen Drive
Concord, NH 03301 |
| Phone #: | (603) 271-2910 |
| E-Mail Address: | tandrews@des.state.nh.us |
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