Congressional District # 8
INTERNATIONAL MINERALS (E. PLANT)EPA ID# INT190010876
Last Updated: December, 2013
Site DescriptionThe IMC East Plant site is located in Vigo County approximately 1.8 miles east of the Wabash River and one mile north of Thompson Ditch in a semi-industrial area of Terre Haute, Indiana. The 37-acre plant site is bordered on the west by the Chicago, Milwaukee, St. Paul, and Pacific Railroads and on the east by the Louisville Railroad. The disposal area encompasses approximately six acres in the northwestern portion of the plant site. In 1946, Commercial Solvents Corporation (CSC) used a six-acre segment of this property for manufacturing, packaging, and warehousing of technical grade benzene hexachloride (BHC-tech). BHC-tech is a mixture of several isomers, primarily alpha, beta, gamma, and delta. BHC-tech produced at this site was not purified to produce the gamma isomer of BHC (known as lindane). This material was sold to insecticide manufacturers as a raw material for the production of an insecticide for control of the cotton boll weevil. Production of BHC-tech at this facility ceased in 1954. CSC was purchased by International Minerals and Chemical Corporation (IMC) in mid-1975.
Site ResponsibilityThis site is being addressed through federal, state, and potentially responsible parties' actions.
Threats and ContaminantsGroundwater and soils were contaminated with volatile organic compounds (VOCs) and low levels of BHC. Due to the nature of this chemical, it is unlikely that it migrated into the local water supply system. During sampling, three residential wells were found to contain chloroform and associated derivatives at or above the maximum contaminant level for safe drinking water. The removal of the source of contamination (described below) resulted in the reduction of contaminants to safe levels. Potential health threats included direct contact with or inhalation of contaminated soils and accidental ingestion of contaminated groundwater.
As a result of a 1979 Remedial Investigation conducted by IMC, the presence of BHC-tech residues at the IMC East Plant site was confirmed. Approximately 18,500 cubic yards of contaminated soil, rubble, piping, and other debris were excavated and placed in a secure clay-capped mound. Soil samples were collected and analyzed to assure removal of all soils containing BHC-tech exceeding 50 milligrams per kilogram (mg/kg).
The U.S. Environmental Protection Agency (EPA) proposed the IMC East Plant site for the National Priorities List (NPL) in October 1984 and finalized the site on the NPL in June 1986. EPA selected a remedy for the site in a Record of Decision (ROD) dated June 22, 1988. The ROD specified groundwater monitoring through December 2010 (30 years following closure of the site), maintenance of cap and site security, deed restrictions, and a performance review every five years.
EPA deleted the IMC East Plant site from the NPL on February 11, 1991.
EPA approved the first five-year review report for the site on September 27, 1996, and the second five-year review report on March 29, 1999. The results of the five-year reviews indicated that the clay cap, fencing, and groundwater monitoring program remained operational and functional. The gamma isomer of BHC-tech (commercially known as lindane) was not detected in the groundwater, indicating that the levels of lindane had declined and were below EPA's established maximum contaminant level goal of 0.2 micrograms per liter (µg/l).
EPA signed the third five-year review report on April 28, 2004, and the fourth five-year review report on January 23, 2009. Both reviews showed that lindane was not detected in groundwater and that the remedy was functioning as intended.
In September 2009, EPA issued an Explanation of Significant Differences (ESD) which documented a significant difference in the site remedy described in the ROD. The ESD outlined the need to include long-term institutional controls (ICs) that run with the land beyond the date established in the ROD for the end of groundwater monitoring (i.e., December 2010). As a result, the potentially responsible parties finalized and recorded a restrictive covenant in January 2011 that established these necessary long-term ICs. Since the required ICs are in place, groundwater monitoring at the site is no longer required. The site monitoring wells were properly abandoned in July 2012, and EPA and the State conducted a site inspection in November 2012 that the work was done properly.
EPA signed the fifth five-year review report on December 27, 2013. The review concluded that the remedy remains protective of human health and the environment.
ContactsRemedial Project Manager, U.S. EPA
demaree collier (email@example.com)
AliasesIMC TERRE HAUTE EAST PLANT
TERRE HAUTE EAST PLT
IMC TERRE HAUTE EAST PLT