The Mallinckrodt site, formerly known as the HoltraChem Manufacturing Company, in Orrington, Maine is located on a 235-acre site on the banks of the Penobscot River. Approximately 77 acres were affected by site operations including 50 acres that are developed and include the manufacturing facility, five landfills, a surface impoundment and a waste pile. The immediate plant area is approximately 12 acres. It opened in 1967 and manufactured chlorine, caustic soda (sodium hydroxide) and chlorine bleach (sodium hypochlorite) used by paper mills. The plant also manufactured hydrochloric acid and the pesticide chloropicrin. The plant closed in September, 2000. In early 2014 the site was split into two properties, one owned by Mallinckrodt US LLC and one owned by the Town of Orrington.
The plant used a chlor-alkali process to separate sodium and chlorine from salt water. In this process, elemental mercury was used as a cathode to collect the sodium from the water. The chlor-alkali process is an older technology and has been replaced by mercury-free production techniques at newer plants and some converted older plants. When it stopped operations in 2000, HoltraChem was one of 13 chlor-alkali plants left in the country. There were as many as 30 chlor-alkali plants in the United States at one time.
This particular plant has been owned and operated by three different companies. The plant began operation in 1967, and was first owned by International Minerals and Chemical Corporation (IMC), which in the 1990's became known as the Mallinckrodt Group. In 1974 IMC sold the plant to Sobin Chemical, a subsidiary of Mallinckrodt that was absorbed back into the parent company in 1977. IMC then sold the plant in 1982 to LCP Chemical and Plastics Inc. In 1988 LCP changed its name to the Hanlin Group. Hanlin filed for bankruptcy in 1991. HoltraChem purchased the property in 1994.
A site investigation determined that the Mallinckrodt site, including parts of the Penobscot River, is contaminated. The site contaminants include mercury, chloropicrin, volatile organic compounds, semi volatile organic compounds, and polychlorinated biphenols (PCBs).
Specifically, the following contaminants at a minimum are present on site:
- Soils: chloropicrin, arsenic, barium, cadmium, chromium, lead, mercury, and PCBs.
- Groundwater : 1,1 dichloroethane, acetone, bromodichloromethane, bromoform, carbon disulfide, carbon tetrachloride, chlorobenzene, chloroform, chloromethane, chloropicrin, dibromochloromethane, methylene chloride, tetrachloroethene, trichloroethene, manganese, mercury, potassium, and sodium.
- Surface Water: carbon tetrachloride, chloroform, mercury, sodium, and pH.
- Sediment: mercury
- Biological samples: mercury