PUBLIC HEALTH ASSESSMENT
NEW HAMPSHIRE PLATING COMPANY
MERRIMACK, HILLSBOROUGH COUNTY, NEW HAMPSHIRE
SUMMARY
The New Hampshire Plating Company site was formerly an electroplating operation in Merrimack, Hillsborough County, New Hampshire. Concentrations of cadmium in surface water, sludge and soil prior to remedial activities were at levels of public health concern for children playing on-site and NHPC workers. Dust samples taken from inside the NHPC building contained cadmium and chromium at levels of public health concern. Indoor air concentrations of cadmium, chromium and nickel inside the NHPC building prior to sampling may have posed an increased carcinogenic risk.
Exposure to cadmium can damage the kidneys, stomach or intestines. The kidney is the main target organ of cadmium toxicity which is often indicated by the presence of protein in the urine. Protein in the urine has been noted to persist after exposure has ceased. Smokers exposed to cadmium are particularly susceptible to illness or injury. Chromium toxicity is associated with lung, stomach and intestinal damage. Inhalation of chromium is primarily associated with respiratory toxicity while ingestion can lead to stomach and intestinal effects. Inhalation of dusts containing cadmium, chromium and nickel compounds have been associated with increased lung cancer.
Citizens raised several questions about the spread of contamination from the site, and about the safety of using the Merrimack River and Horseshoe Pond for recreational activities. Detailed answers to those questions appear in the Public Health Implications section of this public health assessment.
The Agency for Toxic Substances and Disease Registry (ATSDR) has recommended (1) reducing the presence of and preventing exposure to contaminants; (2) better characterizing the site; (3) implementing health follow-up and other activities, and (4) addressing community health concerns.
ATSDR's Health Activities Recommendation Panel (HARP) has determined that follow-up health studies are not indicated because the exposed population cannot be identified, and there is no documented current exposure. HARP has referred the New Hampshire Plating Company site to the National Institute of Occupational Safety and Health (NIOSH) and the Occupational Health and Safety Administration (OSHA) for possible health follow-up of exposed former workers. In addition, HARP determined that community health education should be considered after public comments on the assessment are evaluated. In response to HARP recommendations and other considerations, public health actions have been taken by the ATSDR, the Environmental Protection Agency, the New Hampshire Department of Public Health Services, and the New Hampshire Department of Environmental Services.
ATSDR considers this site a public health hazard because of evidence of past human exposure to
contaminants at levels that could cause illness or injury. The site is also classified as an
indeterminate public health hazard because there are insufficient data to determine whether site
related contaminants could move through bedrock groundwater beneath the Merrimack River to
wells in Litchfield, NH.
BACKGROUND A. Site Description and History
The 13.1-acre New Hampshire Plating Company (NHPC) site, a former electroplating operation, is in the City of Merrimack, Hillsborough County, New Hampshire. The site is on Wright Street off Daniel Webster Highway, 500 feet west of the Merrimack River and about 900 feet north of Horseshoe Pond, which is an oxbow lake in a former channel of the Merrimack River (1). Since the Fall of 1991, the site has been surrounded by an eight-foot fence that is topped with three strands of barbed wire. The site contains the former electroplating operations building, a paved parking lot, a 6,000-gallon underground storage tank, and a wastewater lagoon system. The lagoon system is enclosed by a six-foot fence, which was erected in 1986-87. Important on- and near-site features are shown in Appendix A, Figures 1 and 2.
Between 1962 and 1985, large volumes of electroplating wastes were discharged into a system of four unlined lagoons. Electroplating operations at NHPC used assorted metals, including gold, silver, tin, copper, nickel, cadmium, chromium, and zinc. Cyanide wastes, metal plating sludge, acids, and solvents were routinely discharged to the lagoon system, which consists of an infiltration lagoon (Lagoon 1) and three overflow lagoons (Lagoons 2, 3, and 4). Lagoon 1 received effluent (wastewater) from the electroplating operations building. Lagoons 1 and 2 were connected by an overflow pipe. Lagoon 4 is east of Lagoons 2 and 3, and received waste overflowing the embankments of those two lagoons. The lagoon system is in what were once natural wetlands, which appear to have been altered by disposal practices at NHPC (2). North of the lagoon system, inside the perimeter fence, is a separate, undefined wetlands area that probably received some wastewater from the lagoon system overflow (Appendix A, Figure 2). The interior of the NHPC operations building was contaminated with high levels of heavy metals.
In 1980, NHPC officials notified the U.S. Environmental Protection Agency (EPA) that the operation was a hazardous waste disposal facility as defined by the Resource Conservation and Recovery Act (RCRA). When the property was inspected by the New Hampshire Department of Environmental Services (NHDES) and the EPA in April of 1982, several violations were noted. As a result, a Notice of Violations and Order of Abatement were issued to NHPC by the New Hampshire Division of Public Health Services (NHDPHS). Operations at NHPC ceased in 1985 because financial resources necessary to meet compliance standards and to continue hydrogeologic investigations at the property were lacking (2).
In June 1987, a contractor for NHDES conducted interim remedial activities at the NHPC site:
treatment of the lagoon system with lime and sodium hypochloride solution, removal of debris,
drums, and plating tank liquids from the property, and some cleaning of the former
manufacturing building. In May 1990, EPA initiated emergency actions at the site; they were
concluded in November 1991 (3). EPA took the following major remedial actions:
During 1990 and 1991, the Agency for Toxic Substances and Disease Registry (ATSDR) performed several health consultations for NHPC using data provided by EPA. Following are summaries of those health consultations:
EPA asked ATSDR to review and comment on the results of sediment sampling of the Merrimack River, which was recommended by ATSDR in its January 30, 1991, health consultation. The results of that evaluation are in Appendix D-4.
A fifth health consultation is included as Appendix D-5 which addresses the separate issue of mercury in Horseshoe Pond fish. This consult was followed by a Fish Consumption Advisory issued by NHDPHS in June of 1994. The mercury found in Horseshoe Pond fish is not thought to be site related.
The New Hampshire Plating Company site was added to the National Priorities List (NPL) in
October, 1992. In September, 1992 EPA initiated a Remedial Investigation/Feasibility Study
(RI/FS). The RI/FS will further characterize the extent of contamination in soil and groundwater
and will evaluate alternatives for cleaning up the site. A Draft Remedial Investigation Report
was issued as part of the RI/FS by EPA in September, 1994.
B. Site Visit
Dr. Adrienne Hollis and Mr. Gregory V. Ulirsch, ATSDR, Atlanta, Georgia, and Ms. Louise House, ATSDR regional representative, Boston, Massachusetts, visited the site on September 23, 1991. EPA Representatives and their contractors conducted and were present during the site tour. In addition, a representative of NHDES, the Merrimack Health Officer, and a town selectman were present for the site tour. The following actions were made during the site visit:
After the site tour, the ATSDR staff toured residential and commercial areas near the site. The following observations were made:
The site was revisited on May 19, 1994 by Dennis Pinski and Robert Duff (NHDPHS), Greg Ulirsch (ATSDR/Technical Project Officer) and Ted Bazenas (ATSDR/Regional Representative). The initial EPA removal actions noted above were completed at the time of this visit and a large soil pile was visible on the site. The fence appeared to be in good condition. Several people were observed fishing in the nearby Horseshoe Pond.
Later discussions with the NHDES site manager revealed that the large soil pile consisted of fixated soils taken from the highest areas of contamination in each of the lagoons. Soils from the lower areas of contamination in the lagoons were consolidated in Lagoon 1 and continue to be a source of groundwater contamination. A non-time critical removal action (NTCRA) was undertaken by EPA in December, 1994 which removed the NHPC building and a 6,000 gallon underground storage tank (UST)located beneath its foundation. This action was completed by the end of December, 1994. The area where the building formerly stood was then capped with a synthetic liner to prevent dispersion of contaminants via soil migration and leaching to groundwater.
This information as well as other observations, are incorporated into appropriate sections of this
public health assessment.
C. Demographics, Land Use, and Natural Resource Use
Demographics
Residential populations within one-, two-, and three-mile radii of the site are approximately 860, 15,000, and 23,760 persons, respectively (2,7). Three residences abut the NHPC property line--two west of the site and one north of the site (Appendix A, Figure 2). Homes near the site are representative of moderate-income housing. Within a half-mile radius of the site, are the following potentially sensitive sub-populations (7):
No other potentially sensitive sub-populations are believed to be near the site.
Land Use
The NHPC site is in an area where land use is primarily commercial and industrial, although residential developments and undeveloped lots are found near the site (1). Appendix A, Figure 2, shows all facilities/businesses and residences abutting the NHPC site. Except for private gardens, land near the site is not used for agriculture.
Natural Resource Use
Residents near the site use groundwater from either private wells or public water supplies for drinking water and other household uses. Within a half-mile radius of the site are three private wells; two are believed to be used for domestic purposes (drinking, bathing, watering of lawns and gardens), and one is used by the Jones Chemical Corporation for non-contact cooling water (7). That well is not used for drinking water. NHPC operated a water supply well, at one time, that is not believed to have been used for drinking water (8). Within a half- to one-mile radius of the site, 43 homes, in areas of Litchfield (across Merrimack River) and Merrimack are not served by those respective water companies (2). Currently, no institutional controls are in place that would prevent installation of a private drinking water well. It is unlikely that a drinking water well would be installed, however, because water from the Merrimack Village Water District (MVWD) is available. Businesses near NHPC get their drinking water from MVWD (9).
MVWD operates four municipal wells located within an approximate two-mile radius of the site. Two production wells are located one mile north of the site; the remaining two production wells are located two miles southwest of the site. Appendix A, Figure 3, shows the locations of private and municipal wells. The municipal wells draw water from the overburden aquifer (no name assigned) at a depth of 65-99 feet. An aquifer consists of rock or rock materials sufficiently permeable to conduct groundwater and to yield sufficient quantities of water to wells or springs. MVWD provides about 3.5 million gallons of water per day to the town of Merrimack, NH. About 6,800 units (one per family) are connected to the system. The Pennechuck Water Works (PWW), Nashua, New Hampshire, is used as an emergency water supply during peak demand and low production periods. The PWW primary source of water is a system of reservoirs along the Pennechuck Brook. In the summer, when the water table is low and demand is high, a pumping station on the Merrimack River serves as a supplemental water source. The PWW pumping station is about 2 and a fourth miles downstream of the site (2). Water is pumped from the Merrimack River into several mixing ponds where it is mixed with production well water. The water is treated by chlorination, clarification, and filtration before discharge for municipal use (7). Some residents across the Merrimack River in Litchfield and other areas are served by the Southern New Hampshire Water Company (SNHWC). Five of the six wells operated by that water company are within a four-mile radius of the site (2). The nearest SNHWC wells are in Litchfield; the wells are three to four miles from the site and draw water from overburden aquifers (10).
Horseshoe Pond is an oxbow lake used for various recreational purposes, including boating, swimming, and fishing. The pond is a very limited watershed, according to information from topographic maps; therefore, groundwater was probably the predominant source of water before construction of several beaver dams in the area. Because of those beaver dams, the Naticook Brook currently flows into the pond rather than into the pond's outlet stream. Groundwater may still be the predominant source of water for Horseshoe Pond. Because of the configuration of the pond, groundwater and surface water may mix only minimally (11). The Merrimack River is used for fishing, boating, and duck hunting (7).
Health outcome data were not evaluated for this site because the population of concern
(approximately 50-75 people) is too small to yield reliable results. Additional details of why
those data were not analyzed are presented in the Health Outcome Data Evaluation subsection in
the Public Health Implications section of this public health assessment.
COMMUNITY HEALTH CONCERNS
As part of its investigation of the site, ATSDR staff held two informal, one-on-one public availability sessions to learn about citizens' site-related concerns. Sessions were held on Monday, September 23, 1991, and on Tuesday, September 24, 1991. These sessions were held at the Merrimack New Town Hall. About 14 people, including several town officials, attended one or the other of the two sessions.
Residents and officials expressed the following health-related concerns:
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