Parsons Chemical Works, Inc. sits on about 6 acres in Oneida Township, Grand Ledge, Michigan. The site operated as an agricultural chemical mixing, manufacturing, and packaging facility from 1945 through 1979. Waste disposal from those operations contaminated soil, sediments, surface water, and groundwater. The site was added to the National Priorities List (NPL) in March 1989 and has one cleanup area, called Operable Unit 01, focused on final cleanup of those contaminated areas.
EPA identified 14 contaminants of concern in groundwater at the site. Thirteen are metals: aluminum, antimony, arsenic, cadmium, chromium, cobalt, iron, lead, manganese, nickel, sodium, vanadium, and zinc. The fourteenth is dieldrin, a pesticide. Health risks involve people ingesting or coming into contact with contaminants in soil, sediments, surface water, and groundwater.
The Michigan Department of Environmental Quality led cleanup with EPA funding. Contaminated soil was removed in 1990, 1998, and 1999. A final remedy was selected in September 1997 and called for in-situ vitrification, a process that melts and solidifies contaminated soil in place, along with groundwater monitoring starting in 2003. Construction of the remedy was completed in March 1999. In May 2024, EPA issued an Explanation of Significant Differences to add institutional controls to the remedy, protecting the treated area from future unacceptable use.
Cleanup goals have been achieved. Human exposure is under control, meaning no unacceptable exposure pathways remain. Contaminated groundwater migration is stabilized, and there is no unacceptable discharge to surface water. Monitoring continues to confirm that affected groundwater stays within its original contamination area. EPA's most recent five-year review, completed in September 2024, confirmed the remedy remains protective of human health and the environment in the short term. The long-term remedy requires connecting nearby homes to an alternate water supply if existing supplies become threatened. The site reached construction completion and is ready for anticipated reuse, with one business currently operating on site as of December 2024, employing 10 people and generating an estimated $640,000 in annual sales. The site remains on the NPL.
Community members with questions about the site can contact the EPA's Remedial Project Manager. Site documents, including the administrative record, are available through EPA's Superfund database for public review.
