The Nease Chemical site covers 44 acres near Salem in Columbiana County, Ohio. From 1961 to 1973, the facility made cleaning compounds, fire retardants, and pesticides, including mirex, a probable human carcinogen. Chemical operations left soil and groundwater on the property heavily contaminated. Surface runoff also carried pollution into the Middle Fork of Little Beaver Creek. The site was added to the National Priorities List, which guides EPA cleanup decisions, in September 1983.
Mirex is the primary concern. It has been found in soil, sediment, fish tissue, and floodplains along the Miami-Erie Canal near the site. The Ohio Department of Health issued fishing and swimming advisories for parts of the canal in the late 1980s, and those advisories are currently under review. Dairy herds on nearby farms were exposed to mirex through contaminated creek water, but mirex has not been detected in dairy herds since access restrictions were put in place. Beyond mirex, source areas and groundwater contain a range of chlorinated solvents and benzene, including trichloroethene, tetrachloroethene, vinyl chloride, chloroform, benzene, and several other related compounds.
Cleanup is organized into three operable units covering source areas, groundwater, and sediments. The remedy for source areas and groundwater, selected in 2005, includes soil mixing, air stripping, solidification, engineered caps, and groundwater extraction and treatment. The sediment remedy, selected in 2008, included excavation, dredging, and containment in Feeder Creek and nearby floodplain areas. Remedial action started in April 2017. Physical construction across the site finished in December 2021. A five-year review, which checks whether the cleanup continues to protect health and the environment, was conducted in August 2022. The next five-year review is estimated for August through October 2027.
Despite construction being complete, the site is not fully cleaned up. Groundwater contamination has not yet stabilized, meaning contaminated groundwater is still moving. The site does not meet all goals needed for unrestricted future use. A 2004 assessment found no unacceptable human health risks at that time, but noted that future exposure could pose risks if controls fail. Current human exposure status cannot be confirmed due to insufficient data. EPA estimates a partial deletion from the National Priorities List between August and October 2028.
Community members who want to learn more or ask questions can contact EPA directly. Site documents are also available for public review at the Lepper Library in Lisbon, Ohio and the Salem Public Library in Salem, Ohio.
