US EPA Announces a Settlement Agreement for Investigation of the Olin Chemical Superfund Site

July 13, 2007

The US Environmental Protection Agency has reached a settlement agreement with Olin Corporation, American Biltrite Inc. and Stepan Company for the investigation of the Olin Chemical Superfund Site. These companies will conduct a Remedial Investigation/Feasibility Study (RI/FS) at the Olin Chemical Superfund Site in Wilmington, Mass.

EPA believes these parties, among others, are responsible for investigating and evaluating cleanup options for the site under the Comprehensive Environmental Response, Compensation and Liability Act. Under the settlement, there will be a formal investigation of the site and evaluate the means for addressing hazardous contamination found there, under EPA oversight.

EPA assumed primary responsibility for addressing hazardous substances at the site when, based on groundwater contamination, it added the Olin site to its National Priorities List in April 2006. The Massachusetts Department of Environmental Protection (MA DEP) had overseen the performance of several investigations by the parties under the state’s voluntary cleanup program before referring the site to EPA. EPA expects to build on the results of previous investigations moving forward.

The settlement also requires the parties to continue certain activities, including operation of a groundwater extraction and treatment system, maintenance and performance monitoring of a slurry wall containment area, and design and implementation of a field-scale pilot test to evaluate the feasibility of extracting a plume of Dense Aqueous Phased Liquids (DAPL) from area groundwater.

The first phase of the RI/FS process will require the parties to compile existing data into a comprehensive site report. This will provide an overview of current site conditions and will be used by EPA to determine what data gaps need to be addressed by additional field work and studies. The remedial investigation will also include various risk assessments to determine possible risks posed to human health and the environment by any contaminants present in site groundwater, soil, surface water, sediment and air. Lastly, the settling parties will perform a feasibility study under EPA and MA DEP oversight to evaluate various technologies and methods to address any contamination found to pose an unacceptable risk.

Following public outreach, and a period for review and comment by the public and all interested stakeholders, EPA will formally select a remedy for the site.

Chemical manufacturing began at the property in 1953. The facility at the site produced blowing agents, stabilizers and antioxidants, and other specialized chemicals for the rubber and plastics industry. Prior to approximately 1970, chemicals were discharged into several unlined pits and ponds in the central portion of the property.

Principal contaminants found in the groundwater at the site include ammonia, chloride, sodium, sulfate, chromium, and N-nitrosodimethylamine (NDMA). These chemicals were also found to be present in several of Wilmington’s municipal drinking water wells at Maple Meadow Brook. These wells were taken out of service in 2003.

Source: EPA