INTERIM PUBLIC HEALTH ASSESSMENT
SAVAGE MUNICIPAL WATER SUPPLY
MILFORD, HILLSBOROUGH COUNTY, NEW HAMPSHIRE
The Savage Municipal Water Supply National Priorities List (NPL) site is located along a major highway immediately south of the Souhegan River, in Hillsborough County, approximately 2 miles west of the center of Milford, New Hampshire. Specifically, the site is located in the western portion of the town, along Route 101A (Elm Street), within a half mile of the Savage Municipal Well, and comprises about 0.6 square miles. For the purposes of this interim public health assessment, the site consists of four industries, located along the highway within a half a mile of the Savage Municipal Well, which served as a source of drinking water for the Town of Milford from 1960 to 1983. Due to the diversity of past and present production and disposal operations, the site includes numerous on-site contaminant sources. Site contaminants consist of a variety of volatile organic compounds (VOCs), polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and heavy metals. Site contaminants have been identified in both on-site and off-site surface soil, surface water, sediment, and groundwater (including municipal and private residential wells). There are approximately 30 mobile homes situated in the Milford Mobile Home Park, within a quarter mile of the site, and approximately 20 other homes in the vicinity of the site. Use of the Savage Municipal Well, a well serving the Milford Mobile Home Park, and private residential wells in the area was discontinued when VOC contamination was first identified. Drinking water for residents previously using these sources is currently derived from other municipal water supplies or bottled sources, except for the Milford Drive-In Theater. This site is considered a public health hazard because consumers of water from these contaminated wells probably have been exposed to a variety of carcinogenic and noncarcinogenic VOCs for a number of years.
Exposure pathways of potential concern include direct contact with contaminated soils, surface water, and sediment; inhalation of contaminated soils and VOCs in the air; and incidental ingestion of soils, surface water, and sediment while engaged in recreational activities in area waterways. Potential environmental pathways of contaminant migration include direct discharge of contaminants into soils and into a surface discharge stream which empties into the Souhegan River; discharge of contaminants from industrial subsurface disposal systems into groundwater; leaching of contaminants from soils to groundwater; and discharge of contaminated groundwater to surface waters and migration of contaminated surface discharge to surface waters. Although no information is available on contamination in fish raised at the Milford Fish Hatchery or the Souhegan Valley Aquaculture Facility, both located on the north side of the Souhegan River, this pathway is also of concern since groundwater wells serve as a water source for these hatcheries. Levels of 1,2-dichloroethylene, tetrachloroethylene, and trichloroethylene in residential well waters are of concern because of the risk to public health caused by past exposure and potential future exposure to contaminants via the consumption of contaminated groundwater.
Although there are indications that past exposure to drinking water containing contamination at levels of public health concern has occurred, this site is not being considered for follow-up health activities at this time because the duration and levels of exposure have not been adequately characterized. However, ATSDR recommends that a dose reconstruction analysis be performed to better characterize the duration and levels of exposure. Once the dose reconstruction analysis is complete, the site will be reevaluated for appropriate follow-up health activities.
In 1983, VOCs were detected in the Savage Municipal Well during routine water quality monitoring by the New Hampshire Division of Public Health Services (NH DPHS) - NH Water Supply and Pollution Control Commission (NH WSPCC), now the NH Water Supply and Pollution Control Division (NH WSPCD) of the NH Department of Environmental Services (NH DES). Use of the Savage Municipal Well was discontinued after this contamination was discovered and alternative water supplies were put into use. The Savage Municipal Water Supply Site was placed on the U.S. Environmental Protection Agency's (EPA) National Priorities List (NPL) in 1984. A Preliminary Health Assessment (PHA) for the Savage Municipal Water Supply Site was prepared by the NH DPHS in January 1990 (2). EPA signed a Record of Decision (ROD) for the site on September 27, 1991.
The Savage Municipal Water Supply Site is located in the western portion of the Town of Milford, NH, along Route 101A (Elm Street), within a half mile of the Savage Municipal Well, and comprises approximately 0.6 square miles. For the purposes of this interim public health assessment, the site consists of four industries located along Route 101A (Appendix I). These industries may have contributed to contamination of area groundwater, surface water, and soil with VOCs, PAHs, PCBs, and heavy metals. The four industries identified as Potentially Responsible Parties (PRPs) by EPA are Hendrix Wire and Cable Company, Inc. (Hendrix), Hitchiner Manufacturing Company, Inc. (Hitchiner), New England Steel Fabricators, Inc. (NESFAB), and O.K. Tool Company, Inc. (OK Tool). These four PRPs are located west (Hitchiner and OK Tool) and southwest (Hendrix and NESFAB) of the Savage Municipal Well at distances ranging from approximately 1,600 to 3,400 feet (Appendix II). Since the contamination is associated with four industries spread out along a major roadway, delineation of the actual site is vague. For the purpose of this interim public health assessment, the grounds of the four industries will be considered on-site, while all other areas, including the Savage Municipal Well, will be considered off-site.
The Savage Municipal Well is a gravel packed well with a sustained yield of 180,000-240,000 gallons per day that served as a source of drinking water for the Town of Milford from 1960 to 1983. When in operation, the well supplied approximately 40% of the town's water supply. The water from the Savage Municipal Well was mixed with other groundwater well sources prior to distribution. The amount of mixing varied with the distance from the well. In February of 1983, water quality monitoring by the NH WSPCC detected over 500 parts per billion (ppb) total VOCs in the well water, which included: tetrachloroethylene, 1,1,1-trichloroethane, 1,2-dichloroethylene, 1,1-dichloroethane, and trichloroethylene. This was the first sample of this well ever analyzed for VOCs. Four of these five compounds, the exception being 1,1-dichloroethane, were also present in the nearby Milford Mobile Home Park water supply well, which is located approximately 1,200 feet upgradient of the Savage Municipal Well. Use of both of these water supply wells was discontinued in February 1983, after these VOCs had been identified. The Town of Milford relied on existing water supplies while the Milford Mobile Home Park was connected to the municipal water supply system with emergency funding provided by EPA. The Savage Municipal Well was purchased from the Town of Milford by Hitchiner as a potential future source of industrial process water and the town water supply was subsequently expanded by an interconnection with the Pennichuck Water Works of Nashua, NH. Drinking water for the area is currently derived from municipal sources with the exception of a dug well used by the Milford Drive-In Theater and private wells located on the north side of the Souhegan River on North River Road (3). The only contaminant detected in this well was a low level of tetrachloroethylene (1.07 ppb) in April of 1989. This well is used only during limited nighttime hours, during operation of the Drive-In Theater, in the spring and summer months. Production wells at the Hitchiner and Hendrix facilities continue to utilize local groundwater for industrial process and cooling water. Production wells are also used at the George Brox, Inc./Granite State Concrete property, the Milford Fish Hatchery, and the Souhegan Valley Aquaculture Facility.
Further sampling of surface water and groundwater by the NH WSPCC indicated that contamination was widespread throughout the region around the site. The NH WSPCC, in conjunction with the NH DPHS initiated investigations into the potential sources of the contaminants. Inspection of the facilities of the four PRPs (Hendrix, Hitchiner, NESFAB, and OK Tool) and of several of the smaller commercial establishments in the area was conducted in February 1983 to assess the prevailing waste management practices and the potential impacts on groundwater quality. Subsequently, hydrogeologic investigations were initiated at OK Tool and Hitchiner by privately retained consultants (Normandeau Associates, Inc., Bedford, NH and Roy F. Weston, Inc., Concord, NH). In the summer and fall of 1984, the NH WSPCC implemented a hydrogeological study of the area which resulted in a hydrogeological investigation report being issued in 1985 (4). The data from the two consultant investigations were incorporated into the NH WSPCC report. The following is a brief description of the operational activities carried out at each of the four PRPs, along with the hazardous materials used and the wastes generated at each facility.
Hendrix began operation in 1958 and manufactures high voltage power cable constructed of polyethylene coated wire and cable. Hendrix generates small quantities of the following hazardous wastes: acetophenone, methylene chloride, 1,1,1-trichloroethane, and xylene. Acetophenone is a byproduct of the vulcanization process and methylene chloride is used to clean the polyethylene coating of wire prior to printing identification labels and to periodically clean the printing machines used in the process. Small amounts of 1,1,1-trichloroethane are used to clean the ends of cables prior to electrical testing. Xylene is used in small amounts in the chemical testing laboratory. Current Hendrix waste management procedures were found to be satisfactory by the State of NH on February 23, 1983. However, in a memo from the NH Bureau of Hazardous Waste Management (NH BHWM), now the Waste Management Division of the NH DES, it was reported that past disposal practices may have included disposal of waste into the drain system or on the ground outside the facility (5). Hendrix has a gravel packed production well which withdraws approximately 150,000-225,000 gallons of water per day which is used for contact cooling water purposes and was ultimately discharged into the Hitchiner-Hendrix discharge stream via permitted outfalls (NPDES Permit Number NH0001571). As of March 1990, Hendrix instituted a closed loop water system and no longer discharges water to the discharge stream (6).
Hitchiner began its operations around 1946 and is an investment casting facility which produces ferrous alloy metal parts. The only VOCs currently used by the company are 1,1,1-trichloroethane and acetone, however, tetrachloroethylene and methyl isobutyl ketone were formerly used. 1,1,1-Trichloroethane is used by the company to clean and degrease metal parts and to etch wax molds prior to receiving the initial coating of casting material. During the February 24, 1983 State inspection of the facility, it was noted that a vapor degreaser in the heat treatment room was located adjacent to a floor drain which was connected to the surface water discharge system (7). Two dip tanks, one in the etch and rinse process area and the other in the non-destructive testing area, also used 1,1,1-trichloroethane and were located near floor drains which were connected to the surface water drainage system. Hitchiner withdraws approximately 400,000 gallons of water per day from a gravel packed well for non-contact cooling and process water which, is ultimately discharged into the facility drainage system and subsequently into the Hitchiner-Hendrix discharge stream via permitted outfalls (NPDES Permit Number NH0001376). In June, 1980, Hitchiner was found to be in violation of NPDES permit conditions for pH, sludge deposits, and metals. The NH WSPCC ordered Hitchiner to cease discharge and remove the sludge deposits from the Hitchiner-Hendrix discharge stream (8). The sludge was removed to the now closed and encapsulated landfill south of Old Wilton Road, and the company instituted a pretreatment program for its wastewater discharge.
NESFAB began operation in 1977 and manufactures steel components for the machine tool and building industries. Hazardous wastes generated by the company are limited to paint sludges and liquid from the water curtain of its painting facility. The liquid from the water curtain contains paint thinner, methyl ethyl ketone (MEK), toluene, and methyl isobutyl ketone (MIBK). 1,1,1-Trichloroethane is used by the company to clean metal pieces prior to applying a primer coat of paint and the paint thinner is used in the painting process. Non-contact cooling water is discharged to a small stream south of the facility. The source of this water is a local public water supply. There is no NPDES permit number for this discharge. A reinforced concrete inground storage tank is utilized as a sump for the water curtain associated with the painting process and to collect paint overspray and sludges. In 1984 the NH BHWM inspected the tank and determined it to be intact. In correspondence with the NH BHWM, NESFAB revealed that on one occasion, approximately 4,000-6,000 gallons of liquid waste from the inground storage tank was discharged in a gravel area at the rear of the facility (9). Prior to this episode, NESFAB had obtained a septic hauler to remove and dispose of its liquid waste.
OK Tool, which operated in Milford, NH, from the 1940's to 1987, manufactured machine tools and machine tool parts and used tetra- chloroethylene as a degreasing and cleaning solvent. An inspection of OK Tool by NH WSPCC and the NH DPHS on February 16, 1983 revealed the following: 1) a pipe was observed to connect the discharge of a vapor degreasing tank to a drain in the plant floor; 2) the area located north of the plant showed signs of the disposal of oily waste and other materials onto the ground; and 3) cooling water used within the facility flowed into an open tank located near the vapor degreaser before it was ultimately discharged to the Souhegan River (NPDES Permit Number 0001104) (10). The inspection led to the issuance of a notice of violation and order of abatement which required the cessation of all discharges of waste and the implementation of a hydrogeological investigation (11). In response to the notice of violation and order of abatement, OK Tool had initiated several water quality monitoring investigations and a hydrogeological investigation was conducted.
As indicated above, the ROD for the site was signed on September 27, 1991. The ROD remedial measures to address groundwater contamination include:
- Installation of a groundwater extraction and treatment system at the concentrated plume area. The system will contain and remove highly contaminated groundwater for treatment using air stripping and ultraviolet oxidation;
- Installation of a groundwater and treatment system within the extended plume area. The system will remove contaminated groundwater from two locations near the middle of the plume and two locations near the end of the plume for treatment using ultraviolet oxidation;
- Reliance on natural attenuation of contaminated groundwater to lower contaminant concentrations through physical, chemical, and biological processes until ground water cleanup levels are met;
- Utilization of institutional controls to reduce the risk to public health from consumption of the groundwater. Institutional controls may include deed restrictions and zoning ordinances to restrict the use of contaminated groundwater. Institutional controls shall be imposed in the area where the risk to public health is outside EPA's acceptable risk range; and,
- Implementation of an environmental monitoring program initiated during remedial design and continuing for three years after attaining groundwater cleanup levels to access the effectiveness of remediation and to confirm that contaminant concentrations in the groundwater have attained cleanup levels. The program will include monitoring of ground water, surface water, sediment, and existing households obtaining drinking water from the aquifer.
A site visit to the Savage Municipal Well Site was conducted by the NH DPHS on January 24, 1990 under the direction of the NH DES Site Manager. The current status of the site and surrounding area, since the 1990 site visit, was updated based on information from the EPA Remedial Project Manager.
Since the majority of the site is spread out along a major highway, a driveby tour of the site and surrounding area was conducted. The grounds of the four industries considered on-site were pointed out. Locations of monitoring wells (both on- and off-site), the Savage Municipal Well, the Hitchiner-Hendrix discharge stream, the Milford Drive-In Theater, the Milford Mobile Home Park, and residences in the vicinity of the site were also noted. The entrance to the OK Tool property is on the north side of Route 101A. An area directly west of this property consists of vacant State-owned land on which the New Hampshire Department of Transportation (NH DOT) began bridge construction in December 1991 (3). The main entrance to the Hitchiner property is on the south side of Route 101A and located to the east of the former OK Tool property. A side entrance to the Hitchiner facility is located on Hollis Street. The former Hitchiner Corporate Offices, which were located on the north side of Route 101A, directly across from the main Hitchiner facility, is now the headquarters of the Milford Police Department. The Hitchiner Landfill is located off of Perry Road, directly south of the main Hitchiner facility. The Hendrix property is situated on the south side of Route 101A, directly east of the Hitchiner property, with two entrances located on Old Wilton Road. The NESFAB property is situated directly south of the Hitchiner property, with an entrance on Old Wilton Road.
Site access by the general public is for the most part unrestricted. The former OK Tool property is not fenced and access is unrestricted. There is limited fencing around portions of both the Hitchiner and Hendrix facilities, however, access to the rest of these properties is essentially unrestricted. Access to the NESFAB property is restricted to the public by fences and a locked gate at the main entrance to the facility.
No noticeable evidence of trespassing was observed at the site. The only potential physical hazards observed at the site were the buildings situated on the properties of the four industries. At the time of the site visit, the site was not undergoing remediation.
The area surrounding the site is characterized by a variety of uses ranging from agricultural to heavy industrial interspersed with commercial and residential development. The area immediately northwest and east of the site is utilized for agricultural purposes. The Savage Municipal Well is located east and northeast of the site at distances ranging from approximately 1,600 to 3,400 feet from the properties of the four PRPs. The Milford Mobile Home Park and Milford Drive-In Theater are located east and northeast of the site, respectively, between the Souhegan River and Route 101A. Residential properties exist along Old Wilton Road, Perry Road, North River Road (3), and the eastern end of Route 101A.
There are three principal surface water features that traverse the site. The Souhegan River flows from west to east along the northern edge of the site area. Recreational use of the river for fishing and canoeing was indicated by the NH DES Site Manager. Tucker Brook flows from the southwest corner of the site, through the southern portion of the site, and eventually discharges into the Souhegan River to the east. The Hitchiner- Hendrix discharge stream originates from process water outflow discharging from the Hitchiner and Hendrix facilities. This discharge stream starts at a small discharge pond on the northern border of the Hitchiner property, along the south side of Route 101A past the Hendrix facility, and under Route 101A to the north. The discharge stream then runs to the northeast past the Milford Mobile Home Park, through farmland, eventually discharging into the Souhegan River. Visual evidence of possible contamination observed during the site visit was indicated by the appearance of vapors or steam coming from the surface of the discharge water along the entire length of the Hitchiner-Hendrix discharge stream.
Subpopulations potentially at risk would be children playing on-site near the properties of the four PRP industries. Children could potentially be exposed to contaminated soils in the area by direct contact, ingestion, or inhalation of fugitive dusts from the site. The probability of exposure via these routes is unlikely and could only occur if on-site subsurface soils were to be disturbed.
The approximately 12,000 residents of the Town of Milford may be potentially affected by contaminants present at the Savage Municipal Water Supply Site. The employees at the three PRP facilities still in operation at the site (Hendrix, Hitchiner, and NESFAB) could be potentially affected by contaminants present on-site. The only potentially sensitive populations in the vicinity of the site would be children playing on the properties of the four PRP industries. Land uses within the site area are varied and include residential, agricultural, commercial, light industrial, and heavy industrial uses. Heavy industrial uses are concentrated on-site along Route 101A, on the properties of the four PRPs. A number of smaller commercial and light industrial operations are located throughout the length of Route 101A. Agricultural uses consist of cornfields and a sod farm situated to the east and northeast of the site and extending from Route 101A northward to the Souhegan River. An area comprising the sod farm and adjacent farmland (Hayward Farms) is being proposed for development as a golf course and driving range. Other land uses, across from the site, on the north side of the Souhegan River include, residential and agricultural properties, the Milford Fish Hatchery, and the Souhegan Valley Aquaculture Facility (a privately owned fish hatchery). The water supply wells for both fish hatcheries are north of the Souhegan River about 1,000 feet east of where Purgatory Brook enters the river (3).
The predominant landform feature of the Savage Municipal Water Supply Site is the floodplain of the Souhegan River Valley, a relatively flat land surface extending throughout the majority of the area of the site. The site is underlain by thick (up to 130+ feet) sequences of glacial and fluvial sand and gravel deposits that comprise an aquifer which formerly supplied water to the Savage Well and currently supplies production wells at the Hitchiner and Hendrix facilities and other businesses (3). Several small hills, glacial depositional features, are present within the floodplain. These include a landform located near the center of the site, immediately southwest of the Savage Municipal Well, which has been used for sand and gravel quarrying.
Three principal surface water features traverse the site: 1) the Souhegan River, which flows from west to east through the northern portion of the study area; 2) Tucker Brook, which flows from the southwest corner of the site, through the southern portion of the site where it is associated with several wetland areas, and eventually discharges into the Souhegan River at the eastern end of the site; and 3) a process water discharge stream (the Hitchiner-Hendrix discharge stream), originating from the Hitchiner and Hendrix facilities, which flows southwest to northeast, through a farmland area, across the central portion of the site and into the Souhegan River. This farmland surrounding the Savage Municipal Well is planted with feed corn intended for silage (Appendix II).
An evaluation of the New Hampshire Vital Statistics--1988 Annual Report, related to the cancer incidence rate in the Town of Milford, NH, was performed for this interim public health assessment.
Health concerns in the area of the site were reportedly initiated as a result of the death of two cows that had grazed on the farmland (Savage Farm) that surrounds the Savage Municipal Well (2). A veterinary examination was performed on the animals with inconclusive results and there being no documented evidence to connect the deaths of these animals to exposure to contaminants from the site (13). The Milford Town Health Officer has indicated that, to his knowledge, there are no known public health concerns or complaints by area residents regarding the Savage Municipal Water Supply Site at the present time (14).
The EPA and the NH DES held a public meeting on August 8, 1990, at the Milford Town Hall to discuss the preliminary results of the RI (1) and the Risk Assessment (15) for the Savage Municipal Water Supply Site. The RI/FS was released in the summer of 1991 (3). The main findings of the RI included 1) a plume of VOCs in groundwater running from the site towards the Souhegan River, 2) VOC contamination of bedrock wells on both sides of the Souhegan River, 3) VOC, PAH, PCB, and metal contamination of soil, 4) VOC contamination in the Hitchiner-Hendrix discharge stream, 5) VOC, PAH, PCB, and metal contamination of sediments, 6) the presence of low levels of VOCs in ambient air near the site, and 7) the determination of groundwater flow rates across the site to estimate travel times for VOCs in groundwater. The major results of the Risk Assessment included 1) an examination of both the current site use and exposure pathways, as well as, future site use and future exposure pathways; particularly household use of groundwater for consumptive purposes and 2) the identification of the four principal environmental pathways for human exposure to contaminants of concern at the site, which are, a) direct contact and ingestion of contaminated soil, b) direct contact and ingestion of contaminants in surface water and sediments, c) inhalation of vapors or dust, and d) potential future exposure to contaminants in groundwater via ingestion, direct contact, or inhalation.
Issues raised at the public meeting included the extent of groundwater contamination, explanations of the Superfund process, proposed construction of the NH DOT bridge near the OK Tool property, timeframes for site cleanup activities, and the future uses of the site after cleanup is completed. Questions asked at the meeting were mainly related to site cleanup activities. The only health related question asked was whether the Risk Assessment's exposure scenario for the household use of contaminated groundwater was based on treated or untreated groundwater. EPA responded that the assumptions for this exposure scenario were based on the use of untreated groundwater at an unremediated site. Since no households currently use any of the contaminated groundwater for consumptive purposes, this is considered to be a potential future risk and not a present health risk.
On May 28, 1991 EPA held a public informational meeting to present the Proposed Plan and more than 200 people attended. Public comments at that meeting focused on economic issues (ROD).