The Chem-Dyne site covers 21 acres in Hamilton, Ohio, where the Chem-Dyne Corporation processed and stored chemical wastes from 1974 until operations ended in 1980. The site was added to the Superfund National Priorities List in September 1983 after environmental incidents including fish kills in the Great Miami River and onsite fires. It is currently in the Post-Construction Completion phase, meaning physical cleanup work is done but not all cleanup goals have been fully met.
Thirty-four contaminants of concern have been identified across groundwater, soil, and buildings at the site. Groundwater contains chlorinated solvents such as trichloroethene, tetrachloroethene, benzene, chloroform, and carbon tetrachloride, along with pesticides including chlordane, dieldrin, heptachlor, and DDT, plus arsenic, polychlorinated biphenyls (PCBs), and hexachlorocyclohexane compounds. Soil contamination includes arsenic, asbestos, PCBs, dieldrin, chlordane, and hexachlorobenzene. Buildings on the site contain arsenic, asbestos, PCBs, benzo[a]pyrene, hexachlorobenzene, and dieldrin.
Cleanup actions began with emergency removal work in 1980, including stabilization of 17 potentially explosive drums. Later actions included demolition of all onsite buildings, excavation of contaminated soil in hot spot areas, installation of a protective cap, removal of roughly 9,000 drums, and treatment of 200,000 gallons of liquid and solid wastes from storage tanks. A groundwater extraction-injection system was installed, and the storm drain was plugged to prevent contaminated discharge into Ford Canal. In June 2024, EPA modified the cleanup plan to adjust pumping rates, add a soil vapor extraction system, and decommission portions of the groundwater treatment system.
Human exposure is currently under control, with no unacceptable exposure pathways identified. Groundwater migration has also been stabilized with no unacceptable discharge to surface water. The site remains on the National Priorities List and has not yet achieved sitewide ready-for-anticipated-reuse status. Land-use restrictions and controls are still being put in place.
EPA is now conducting its sixth five-year review, expected to be completed by February 2026. This review is required by law to confirm the cleanup continues to protect public health and the environment. Community members are invited to share comments or concerns with the EPA Remedial Project Manager during this review period. Public records related to Superfund work at the site are available at the Hamilton Municipal Building, 345 High Street, Suite 520, in the Public Works Department.
