| Site Type: Long Term/National Priorities List (NPL) |
SAVAGE MUNICIPAL WATER SUPPLY WELL
Map this site in Cleanups in My Community
| Milford,  New Hampshire|
| Hillsborough County
| Street Address: ||Elm Street |
| Zip Code: || 03055 |
| Congressional |
| EPA ID #: ||NHD980671002 |
| Site ID #: ||0101145 |
| Site Aliases: ||OK Tool|
| Site Responsibility: ||Federal, State, Potentially Responsible Parties |
| NPL LISTING HISTORY |
| Proposed Date ||09/08/1983|
| Final Date ||09/21/1984 |
The Savage Municipal Water Supply Well 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 Municipal 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.
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, following closure of the contaminated water supply wells, the EPA provided bottled water to 75 residents at the Millhaven Mobile Home Park who were affected by contaminated well water. 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 OU1 (OK Tool Source Area). The design was completed in 1996 and a contract for the construction was awarded in November 1997. Construction of the slurry wall 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 OU2 Extended Plume Area. The remainder of the OU2 groundwater plume area would be allowed to cleanse itself through natural attenuation. Design of the pump and treat system was completed in December 2003; construction 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 recent and historic drought conditions as well as 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 Source Area ||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 a 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 and newly installed wells within the slurry wall, EPA and NHDES have conducted several 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 2-3% and injected into the ground where it destroys the PCE through an oxidation chemical reaction. The first injection consisted of 8000 pounds of potassium permanganate in September, 2003. A second injection consisted of 24,000 pounds of potassium permanganate in October, 2004. A third injection of 111,773 pounds of sodium permanganate was completed in November 2008, and a fourth injection of 149,031 pounds of sodium permanganate was completed in the November 2009. |
|Operable Unit 2 - Extended Plume Area ||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 expedite the overall clean up time of the OU2 remediation.|
In 2011 and 2012, samples were collected from the shallow groundwater in the vicinity of the Millhaven Mobile Home Park. The samples were collected to investigate the potential for vapor intrusion within occupied buildings in this particular area of OU2. The sampling results were compared against applicable vapor intrusion screening levels and were found to be within acceptable risk-based criteria. It was determined that no further investigation would be required.
|Operable Unit 1 - Vadose Zone Excavation and Treatment ||EPA and NHDES investigated newly identified areas of high contaminant concentrations located at shallow depths within the slurry wall in 2006 and 2007. The investigations led to the excavation, in 2008, of about 20,000 tons of highly contaminated soil above the water table. The soil was treated in 2009 using an ex-situ chemical treatment process together with a vapor extraction. The treated soil was placed back into the original area from which it was excavated in the fall of 2009. |
|Bedrock Investigation ||In 2010, investigation of the extent of VOC contamination within the deeper bedrock underlying the Site was initiated. The investigation included drilling bedrock boreholes, collecting water quality samples, conducting pumping tests and characterizing bedrock fractures. In July 2012, EPA published a Technical Memo detailing the bedrock investigation data collected to date. Concentrations of VOCs in the bedrock fracture zones were detected during all bedrock sampling events. The investigation of the extent of contamination in bedrock has been completed and a RI Report was published in March 2014. Results of the investigation were used to evaluate the feasibility of remedial alternatives to address the contamination. EPA is considering a ROD amendment to the current OU1 remedy to address contamination in the bedrock aquifer. |
|Operable Unit 1 - Groundwater Treatment ||Groundwater from OU1 is successfully being extracted from the source area and treated to remove the contaminants of concern. The treated ground water is returned to the subsurface via a recharge gallery.|
|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. |
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 Well site. Groundwater cleanup at OU1 is continuing, including the pumping and treating of contaminated groundwater, as well as treatment with permanganate injection. Operation of the groundwater pump and treatment facilities at OU2 began in late November 2004 and is ongoing. Monitoring is frequently conducted at both OU1 and OU2 to track the concentration of contaminants remaining in the groundwater.
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 and sodium permanganate were done in 2003, 2004, 2008 and 2009 within the slurry wall of OU1 to further reduce the amount of contamination in groundwater through treatment.
Remediation of 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. The OU 2 treatment system has operated continuously, except for scheduled maintenance, since 2006, and has successfully reduced the level of contaminants in groundwater in the Extended Plume.
An investigation into the extent of contamination in deep bedrock included the drilling of several bedrock boreholes, collecting water quality samples, conducting a pumping test and characterizing bedrock fractures has been conducted. These investigations were documented in an RI Report that was published in March 2014. EPA is currently evaluating the feasibility of various remedial alternatives for addressing contamination in deep bedrock, as well as enhancing remediation in the overburden aquifer, within OU1. To date, no contamination has been detected in any of the residential bedrock wells that have been sampled within and in close proximity to the site area.
OU 2 Treatment Plant
Links to Other Site Information
Newsletters & Press Releases:
Federal Register Notices:
Reports and Studies:
|Additional Reports and Studies   |
|Progress Reports   |
|Preliminary Closeout Report (PCOR), OU 01, September 12, 2006 (388 KB)   |
|2008 Annual Report, March 1, 2008 (59 MB with links to other files)   |
|Annual Groundwater Quality Monitoring Report for January 2007 - January 2008, July 23, 2008 (32 MB with links to other files)   |
|Draft 2009 Annual Report, May 1, 2010 (75.4 MB)   |
|Revised Proposed Fall 2010 Annual Groundwater Quality Monitoring Plan, December 13, 2010 (42.7 KB)   |
|Conditional Approval of Workplan for Assessing Vapor Intrusion (VI), June 2, 2011 (723 KB)   |
|Shallow Groundwater Sampling and Analysis Plan, OU2 - December 27, 2011 (159 KB)   |
|2011 Annual Report, June 2012 (36.6 MB)   |
|Bedrock Investigation Technical Memorandum, July 1, 2012 (Opening file is 69.7 MB with a link to an additional PDF file)   |
|Shallow Groundwater Quality Assessment Sampling and Analysis Results, September 11, 2012 (242 KB)   |
|Conditional Approval of the 2011 Annual Groundwater Quality Monitoring Report for OU 2, September 25, 2012 (245 KB)   |
|Final Feasibility Study (FS) Report, July 1, 2015, (7.67 MB)   |
|Final Technical Impractibility Evaluation Report, June 1, 2015, (20.7 MB)   |
Wadleigh Memorial Library, 21 Nashua Street, Milford, NH 03055
OSRR Records and Information Center, 1st Floor, 5 Post Office Square, Suite 100 (HSC), Boston, MA 02109-3912 (617) 918-1440
|EPA Remedial Project Manager: ||Richard Hull |
|Site Responsibilities: ||Remedial Project Manager |
|Address: ||US Environmental Protection Agency|
5 Post Office Square, Suite 100
Mail Code OSRR07-1
Boston, MA 02109-3912
|Phone #: ||617-918-1882 |
|E-Mail Address: ||firstname.lastname@example.org |
|EPA Community Involvement Coordinator: ||Rodney Elliott |
|Address: ||US Environmental Protection Agency|
New England Regional Laboratory
11 Technology Drive
Chelmsford, MA 01863-2431
|Phone #: ||617-918-8372 |
|E-Mail Address: ||email@example.com |
|State Agency Contact: ||Robin Mongeon |
|Address: ||29 Hazen Drive|
PO Box 95
Concord, NH 03302-0095
|Phone #: ||603-271-7378 |
|E-Mail Address: ||firstname.lastname@example.org |