Case Summary: $13.6 Million Order for Additional Cleanup Work at South Municipal Water Supply Well Superfund Site
On September 17, 2012, EPA issued a First Modification to Administrative Order and Statement of Work to New Hampshire Ball Bearings, Inc. (NHBB) and Minebea Co for cleanup work at the South Municipal Water Supply Well Superfund Site in Petersborough, N.H. EPA initially issued a unilateral administrative order (UAO) to NHBB and Minebea Co. in June 1990 to conduct the cleanup work associated with the Record of Decision (ROD) issued on September 27, 1989.
The activities described in the First Modification to the Order and Statement of Work are based upon EPA’s amendment to the ROD, that was signed by the Region 1 Administrator on September 30, 2010. NHBB and Minebea have both agreed to comply with the UAO as modified and the estimated cost of the ROD amendment cleanup work is $13.6 million.
NHBB is a manufacturer of bearings and complex bearing assemblies for the aerospace, defense, medical, dental, and high technology markets. Based in Chatsworth, CA, NHBB operates three manufacturing facilities in the United States and employs over 1,400 people. The company was founded in Peterborough, N.H. in 1946 and was purchased by Minebea Co., Ltd. in 1985. NHBB operates under NMB (USA), Inc., the North American headquarters of the Minebea Group of Companies.
The South Municipal Water Supply Well Superfund Site covers 250 acres in a rural portion of the Contoocook River Valley. The well was installed in 1952 and provided water to the Town of Peterborough, N.H. for nearly 30 years. The well served approximately 4,600 people. In 1982, the state conducted a routine sampling of their water supply and found contaminants in the South Well, at which time it was shut down. The source of the contamination was thought to be the NHBB facility, located 1,200 feet west of the well. In 1955, NHBB purchased the 24 acres it now occupies off of Route 202 in Peterborough. Major source areas on the property include discharges from three drainage outfalls, an inactive leachfield, and drainage from a tank truck used to haul waste from the facility. A brook located 200 feet from the facility drains into a wetland area and Noone Pond before emptying into the Contoocook River. In 1972 the facility connected to the town sewer line and discharges to the leach field and sump ceased. Periodic on-site dumping of a 275-gallon tank truck containing waste solvents ceased in the late 1970s. Floor drains in the plant were sealed in 1983. The population of the Town of Peterborough is over 6,000. Less than 100 single-family residences are located within a 1-mile radius of the Site, and the nearest private residence is located approximately 1,000 feet from the NHBB facility.
The soils near the NHBB facility and surface water in the adjacent wetlands were contaminated with volatile organic compounds (VOCs) including chloroform, benzene, and toluene. Wetland sediments also were contaminated with VOCs and polychlorinated biphenyls (PCBs). Groundwater is contaminated with VOCs. Additional information about the South Municipal Water Supply Well Superfund Site is available on the Region 1 website.
People who accidentally ingest or come into direct contact with contaminated groundwater may be at risk. However, the Town of Peterborough has passed a zoning ordinance which prohibits the pumping or use of groundwater within a Groundwater Protection Overlay Zone that includes the site, and NHBB has placed a deed restriction on its property that restricts the extraction of groundwater from the premises.
The ROD amendment changed the original remedy set forth in the 1989 ROD for the site. Both the original 1989 selected remedy and the ROD amendment selected remedy included a combination of technologies to provide a comprehensive approach for site remediation by targeting treatment of contaminants in soil and ground water located within high concentration source areas. The ROD amendment also eliminates the extraction and treatment requirements for contaminated groundwater, which has failed to provide a level of hydraulic control required to protect the South Municipal Water Supply Well.
Specifically, the ROD amendment selected remedy will include the following major components:
- in-situ thermal treatment of contaminated soil and groundwater in identified source areas;
- in-situ bioremediation of contaminated soil and groundwater after the in-situ thermal treatment program;
- in-situ treatment of contaminated groundwater via a permeable reactive barrier (PRB);
- monitoring and maintenance of existing institutional controls (ICs) that prohibit the use of groundwater;
- long-term monitoring of site groundwater; and
- Five-Year Reviews to ensure that the selected remedy remains protective of human health and the environment.
For more information contact:
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., NW
Washington, DC 20460
Senior Enforcement Counsel
U.S. Environmental Protection Agency
5 Post Office Square
Boston, MA 02109-3912