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The New Hampshire Plating Company site was formerly an electroplating operation inMerrimack, Hillsborough County, New Hampshire. Concentrations of cadmium in surfacewater, sludge and soil prior to remedial activities were at levels of public health concern forchildren playing on-site and NHPC workers. Dust samples taken from inside the NHPC buildingcontained cadmium and chromium at levels of public health concern. Indoor air concentrationsof cadmium, chromium and nickel inside the NHPC building prior to sampling may have posedan increased carcinogenic risk.

Exposure to cadmium can damage the kidneys, stomach or intestines. The kidney is the maintarget 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 tocadmium are particularly susceptible to illness or injury. Chromium toxicity is associated withlung, stomach and intestinal damage. Inhalation of chromium is primarily associated withrespiratory toxicity while ingestion can lead to stomach and intestinal effects. Inhalation ofdusts containing cadmium, chromium and nickel compounds have been associated with increasedlung cancer.

Citizens raised several questions about the spread of contamination from the site, and about thesafety of using the Merrimack River and Horseshoe Pond for recreational activities. Detailedanswers to those questions appear in the Public Health Implications section of this public healthassessment.

The Agency for Toxic Substances and Disease Registry (ATSDR) has recommended (1)reducing the presence of and preventing exposure to contaminants; (2) better characterizing thesite; (3) implementing health follow-up and other activities, and (4) addressing community healthconcerns.

ATSDR's Health Activities Recommendation Panel (HARP) has determined that follow-uphealth studies are not indicated because the exposed population cannot be identified, and there isno documented current exposure. HARP has referred the New Hampshire Plating Company siteto the National Institute of Occupational Safety and Health (NIOSH) and the OccupationalHealth and Safety Administration (OSHA) for possible health follow-up of exposed formerworkers. In addition, HARP determined that community health education should be consideredafter public comments on the assessment are evaluated. In response to HARP recommendationsand other considerations, public health actions have been taken by the ATSDR, theEnvironmental 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 tocontaminants at levels that could cause illness or injury. The site is also classified as anindeterminate public health hazard because there are insufficient data to determine whether siterelated contaminants could move through bedrock groundwater beneath the Merrimack River towells in Litchfield, NH.


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 Streetoff Daniel Webster Highway, 500 feet west of the Merrimack River and about 900 feet north ofHorseshoe Pond, which is an oxbow lake in a former channel of the Merrimack River (1). Sincethe Fall of 1991, the site has been surrounded by an eight-foot fence that is topped with threestrands of barbed wire. The site contains the former electroplating operations building, a pavedparking lot, a 6,000-gallon underground storage tank, and a wastewater lagoon system. Thelagoon system is enclosed by a six-foot fence, which was erected in 1986-87. Important on- andnear-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 offour 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 aninfiltration lagoon (Lagoon 1) and three overflow lagoons (Lagoons 2, 3, and 4). Lagoon 1received effluent (wastewater) from the electroplating operations building. Lagoons 1 and 2were connected by an overflow pipe. Lagoon 4 is east of Lagoons 2 and 3, and received wasteoverflowing the embankments of those two lagoons. The lagoon system is in what were oncenatural wetlands, which appear to have been altered by disposal practices at NHPC (2). North ofthe lagoon system, inside the perimeter fence, is a separate, undefined wetlands area thatprobably 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 heavymetals.

In 1980, NHPC officials notified the U.S. Environmental Protection Agency (EPA) that theoperation was a hazardous waste disposal facility as defined by the Resource Conservation andRecovery Act (RCRA). When the property was inspected by the New Hampshire Department ofEnvironmental 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 NewHampshire Division of Public Health Services (NHDPHS). Operations at NHPC ceased in 1985because financial resources necessary to meet compliance standards and to continuehydrogeologic 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 formermanufacturing building. In May 1990, EPA initiated emergency actions at the site; they wereconcluded in November 1991 (3). EPA took the following major remedial actions:

  • fixated 4,500 cubic yards of contaminated soil and 1,110 cubic yards of sludge. The fixedmaterial is secured in an on-site lined holding cell. All remaining sludge (about 990 cubicyards) was disposed at an off-site CERCLA-approved treatment and disposal facility (4);

  • installed an 8-foot chain link fence, with three strands of barbed wire, at the site perimeter (5);

  • pumped 800 gallons of #2 fuel oil from the underground storage tank under the NHPCoperations building--about one foot of sludge that could not be pumped remains in the tank (5);

  • consolidated and capped the highly contaminated soil in Lagoon 1, covered the remaininglagoons and holding cell with 12-18 inches of clean soil, and seeded the clean soil (6,7); and,

  • secured the NHPC building by installing plywood over doors and windows (3).

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 aresummaries of those health consultations:

  1. Health Consultation: Evaluation of Groundwater and Lagoon Sludge Samples, NewHampshire Plating, Merrimack, New Hampshire, April 18, 1990
EPA asked that ATSDR comment on groundwater and surface sludge samples--see AppendixD-1 for conclusions and recommendations of that health consultation.

  1. Health Consultation: Evaluation of Well Water Samples, New Hampshire Plating Site,Merrimack, New Hampshire, April 18, 1990.
EPA asked that ATSDR comment on analysis of well water samples obtained near NewHampshire Plating site--those comments are in Appendix D-2.

  1. Health Consultation: Evaluation of Soil Clean-up Levels at the New Hampshire PlatingSite, January 30, 1991
EPA asked ATSDR to review and comment on proposed soil clean-up levels at the NewHampshire Plating site--those comments are in Appendix D-3.

  1. Health Consultation: Evaluation of Sediment Sampling Results, April 10, 1991.

EPA asked ATSDR to review and comment on the results of sediment sampling of theMerrimack River, which was recommended by ATSDR in its January 30, 1991, healthconsultation. 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 ofmercury in Horseshoe Pond fish. This consult was followed by a Fish Consumption Advisoryissued by NHDPHS in June of 1994. The mercury found in Horseshoe Pond fish is not thoughtto be site related.

The New Hampshire Plating Company site was added to the National Priorities List (NPL) inOctober, 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 groundwaterand will evaluate alternatives for cleaning up the site. A Draft Remedial Investigation Reportwas 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. LouiseHouse, ATSDR regional representative, Boston, Massachusetts, visited the site on September 23,1991. EPA Representatives and their contractors conducted and were present during the sitetour. In addition, a representative of NHDES, the Merrimack Health Officer, and a townselectman were present for the site tour. The following actions were made during the site visit:

  • the main activity at the site was the ongoing EPA removal action;

  • fences were in good condition. Warning signs were posted throughout the site and on lagoonfences. Several gates were secured with padlocks. At the time of the site visit a portion of thefence on the north part of the site, which abuts a school bus parking depot, did not havebarbed wire; however, since that time, the barbed wire has been added to the top of thisportion of the fence. An area north of Lagoon 3, the undefined wetland area, is not inside thelagoon fence, but is inside the site perimeter fence;

  • windows and doors at the former operations building were either boarded or otherwisesealed--additional measures to seal off the building were completed when EPA finished itsremoval action;

  • before the fence was erected, dirt biking and snow-mobiling took place on site. TheMerrimack Health Officer indicated that children were reported to play in and about thelagoon area before the lagoon fence was erected;

  • the lagoons are natural wetlands--surface water from rain drains toward the lagoon systemfrom the NHPC building;

  • surface soils outside the lagoon system fence were found to be contaminated;

  • the school bus parking depot is used for parking, not for loading or unloading children;

  • the underground storage tank once contained #2 fuel oil and currently contains about one footof sludge (i.e., fuel oil #4).

  • raspberries picked and eaten by remedial workers were from plants outside the perimeterfence.

After the site tour, the ATSDR staff toured residential and commercial areas near the site. Thefollowing observations were made:

  • although the property of the Former Avanti Daycare School (closed June 21, 1991) abuts thesite, the playground area behind the day care building is fenced and is separated by severalhundred feet of relatively thick vegetation;

  • several residences abut or are close to the northern site fence. A vegetable garden was seen inone residential yard;

  • one previously identified private well is at a multiplex house;

  • the lagoon system is almost devoid of vegetation. Areas around the lagoons have moderate tothick vegetation.

The site was revisited on May 19, 1994 by Dennis Pinski and Robert Duff (NHDPHS), GregUlirsch (ATSDR/Technical Project Officer) and Ted Bazenas (ATSDR/RegionalRepresentative). The initial EPA removal actions noted above were completed at the time of thisvisit 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 offixated soils taken from the highest areas of contamination in each of the lagoons. Soils from thelower areas of contamination in the lagoons were consolidated in Lagoon 1 and continue to be asource of groundwater contamination. A non-time critical removal action (NTCRA) wasundertaken by EPA in December, 1994 which removed the NHPC building and a 6,000 gallonunderground storage tank (UST)located beneath its foundation. This action was completed bythe end of December, 1994. The area where the building formerly stood was then capped with asynthetic liner to prevent dispersion of contaminants via soil migration and leaching togroundwater.

This information as well as other observations, are incorporated into appropriate sections of thispublic health assessment.

C. Demographics, Land Use, and Natural Resource Use


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 propertyline--two west of the site and one north of the site (Appendix A, Figure 2). Homes near the siteare representative of moderate-income housing. Within a half-mile radius of the site, are thefollowing potentially sensitive sub-populations (7):

  • Emergency Care Facility--St. Joseph's Hospital Walk-In Center--less than one-fourth milefrom site

  • Child Daycare Facilities--one abuts the site, two others are nearby

    • - former Avanti Daycare school--abuts the site--20-30 children once cared for duringbusiness hours.
      - Childrens World Learning Center--less than one-half mile from site--more than 100children are cared for during business hours.
      - Toll House Childrens Center--less than one-half mile from the site--approximately 85children are cared for during business hours.

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, althoughresidential 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 privategardens, 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 fordrinking water and other household uses. Within a half-mile radius of the site are three privatewells; two are believed to be used for domestic purposes (drinking, bathing, watering of lawnsand 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 ofthe site, 43 homes, in areas of Litchfield (across Merrimack River) and Merrimack are not servedby those respective water companies (2). Currently, no institutional controls are in place thatwould prevent installation of a private drinking water well. It is unlikely that a drinking waterwell 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 wellsare located two miles southwest of the site. Appendix A, Figure 3, shows the locations of privateand municipal wells. The municipal wells draw water from the overburden aquifer (no nameassigned) at a depth of 65-99 feet. An aquifer consists of rock or rock materials sufficientlypermeable 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 demandand low production periods. The PWW primary source of water is a system of reservoirs alongthe Pennechuck Brook. In the summer, when the water table is low and demand is high, apumping station on the Merrimack River serves as a supplemental water source. The PWWpumping station is about 2 and a fourth miles downstream of the site (2). Water is pumped fromthe 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 municipaluse (7). Some residents across the Merrimack River in Litchfield and other areas are served by theSouthern New Hampshire Water Company (SNHWC). Five of the six wells operated by thatwater company are within a four-mile radius of the site (2). The nearest SNHWC wells are inLitchfield; the wells are three to four miles from the site and draw water from overburdenaquifers (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 fromtopographic maps; therefore, groundwater was probably the predominant source of water beforeconstruction of several beaver dams in the area. Because of those beaver dams, the NaticookBrook currently flows into the pond rather than into the pond's outlet stream. Groundwater maystill be the predominant source of water for Horseshoe Pond. Because of the configuration of thepond, groundwater and surface water may mix only minimally (11). The Merrimack River is usedfor fishing, boating, and duck hunting (7).

D. Health Outcome Data

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 whythose data were not analyzed are presented in the Health Outcome Data Evaluation subsection inthe Public Health Implications section of this public health assessment.


As part of its investigation of the site, ATSDR staff held two informal, one-on-one publicavailability sessions to learn about citizens' site-related concerns. Sessions were held onMonday, September 23, 1991, and on Tuesday, September 24, 1991. These sessions were held atthe Merrimack New Town Hall. About 14 people, including several town officials, attended oneor the other of the two sessions.

Residents and officials expressed the following health-related concerns:

  1. The primary community health concerns expressed by individuals at the meetinginvolved potential contamination of Horseshoe Pond and the Merrimack River and possiblehealth effects of exposure to contaminants that may have migrated from the site throughgroundwater.

    Is it advisable to swim in, eat fish from, or use water for irrigation from Horseshoe Pond orthe Merrimack River?

  2. Several citizens wondered if it would be safe to build a ballfield on land across from thesite? They are concerned that a migrating plume of contaminants will reach thegroundwater beneath the land, which is owned by the YWCA.
    Who would monitor the groundwater beneath the YMCA property for contamination?

  3. Who will sample monitoring wells and how often, and will the Merrimack HealthOfficer receive a copy of those results?

  4. If the contaminated materials are not removed for 10 years, could something be donemeanwhile to mitigate the contamination? Also, whatever is done, how often and by whowill the site be inspected?

  5. Has there been any appreciable contamination of the air around the site from removaland remedial actions at the site? Residents believe that the air should be monitored,especially because removal and remediation will cause hazardous materials to becomeairborne.

  6. Could the on-site underground storage tank leak and cause further contamination?

  7. Is the former NHPC building a health concern if left standing?

  8. Is drinking water of acceptable quality being provided to residents in the area? Should awell survey be conducted to determine the number of people who use either municipalwater or private well water?

  9. Are other sources of contamination near NHPC contributing to the problem? Are thosecontamination sources contributing to contamination of the Merrimack River?

  10. Is contamination of this area a health concern and should the area be fenced to preventaccess? Another pond (lagoon #5) off the property line also may be contaminated from thesite.

  11. How stable is and what is the life expectancy of the liner covering the contaminatedsoil in the on-site holding cell?

  12. Was it safe for workers to eat the raspberries?

  13. What is the public health impact of residential gardening in areas adjacent to the site?

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