Third Five-Year Review to Begin, Chemplex Superfund Site, Clinton, Clinton County, Iowa
The U.S. Environmental Protection Agency (EPA) conducts regular five-year checkups, called five-year reviews, on Superfund sites where cleanups have been completed. These regular five-year reviews are required by the Superfund law [42 U.S.C. Section 9621 (c)] to make sure the site remains safe and the cleanup actions continue to protect public health and the environment.
EPA's first five-year review of the Chemplex site was completed in June 1999. The second five-year review was completed in June 2004. Both reviews concluded the remedy continued to be protective.
The Chemplex facility in Clinton County, Iowa, was constructed in 1967 and has been in operation since then. Equistar Chemicals, LP, is the current operator. The facility manufactures high and low-density polyethylene plastics from chemical stock.
Due to past waste disposal practices, ground water and soil at the Chemplex Site were contaminated with volatile organic compounds (VOCs) and polynuclear aromatic hydrocarbons (PAHs). EPA divided cleanup activities at the Site into two phases, called operable units. Operable unit (OU) 1 addressed ground water on a site-wide basis and OU2 addressed contaminated soils and wastes which were sources of ground water contamination.
Status of Site Cleanup
The ground water cleanup included a ground water extraction and treatment system to capture and contain contaminated ground water. It operated from late 1994 until September 2008. In September 2008 it was placed in temporary standby condition as part of a performance test of a revised remedy. The performance test includes allowing the ground water system to return to natural flow conditions, which we believe will both facilitate hot spot treatment and better enable natural attenuation processes to clean up the contaminated ground water. Additional components of the performance test include:
- Enhanced ground water monitoring.
- Hot spot treatment of the most highly contaminated ground water.
- Contingency measures to protect human health and the environment.
- Land use controls to prohibit use of the ground water in the contaminant plume.
- Extension of the City of Camanche municipal water line to residents located downgradient of the site.
EPA will decide at the conclusion of the performance test and after receipt of public comments, whether to implement the remedy being performance tested or another remedy.
The former operators continue to monitor the status of the contaminant plume by collecting and analyzing ground water data. EPA continues to review all monitoring reports and collects and analyzes independent ground water samples to ensure human health and the environment are protected.
The contaminated soils and wastes cleanup addressed source areas for the ground water contamination, including an inactive landfill, the Debutanized Aromatic Concentrate (DAC) Storage/Truck Loading area and other on-site disposal locations. These areas were covered and a soil vapor extraction (SVE) treatment system was used to remove volatile organic chemicals (VOCs). The SVE system is a treatment process that uses vacuum wells to remove hazardous gases from the soil. Construction activities for the OU2 remedy were completed in 1998 and the SVE system operated until 2003, when the specified performance standards were met. The SVE system is no longer in operation.
EPA reviewed all documents related to the design and construction of the system, provided oversight during the construction and testing of the system, and prepared the final report.
The Five-Year Review
The five-year review process includes:
- The review and analysis of existing monitoring and operational data.
- The review of site information.
- The inspection of the site to visually confirm and document the condition of the remedy.
EPA will conduct an inspection of the site as part of the five-year review. Current site information will be reviewed by EPA and the Iowa Department of Natural Resources to make sure the remedy continues to be protective.
We encourage the community to tell us about site conditions or any concerns you my have.
A final report will be prepared at the end of the review and will be available at the site information repositories. The goal is to complete the review and report in June 2009.
Detailed site information, including the first and second five-year review reports, is available at the following locations:
EPA Records Center
901 N. 5th St.
Kansas City, Kan.
Camanche Public Library
102 12th Ave.
Questions or requests for information can be submitted to:
Community Involvement Coordinator
U.S. EPA Region 7
901 N. Fifth St.
Kansas City, KS 66101
Toll free: (800) 223-0425