The Allied Chemical and Ironton Coke site is a 129-acre former industrial property in Ironton, Ohio. It was added to the EPA's National Priorities List (NPL) in September 1983 because coke plant and tar plant operations had contaminated soil, sediment, and groundwater. The site is divided into three cleanup areas: the Goldcamp Disposal Area, the Coke Plant and Lagoon Area, and the Tar Plant Area.
Contaminants found across these areas include polycyclic aromatic hydrocarbons (PAHs), benzene, naphthalene, toluene, ethylbenzene, xylene, styrene, phenolics, arsenic, cyanide, and ammonia. These substances appear in soil, groundwater, sediment, air, and solid waste. EPA determined they posed unacceptable risks to human health and the environment and required cleanup action.
Cleanup ran from 1993 to 2016. The Goldcamp area got a slurry wall and capping system finished in 1995. The Coke Plant and Lagoon Area went through demolition, soil removal, and conversion to wetlands, with construction done by 2001. The Tar Plant was closed in 2000, decommissioned by 2003, and capped in place, with final construction wrapping up in March 2016. In August 2020, EPA removed most of the site from the NPL after confirming completed actions and monitoring showed no remaining threat. The site has not been fully deleted from the NPL. A pump-and-treat system continues to manage contaminated groundwater, and a 2.3-acre solar array completed in 2022 now supplies all of the treatment plant's electricity while offsetting about 817 tons of carbon emissions each year.
EPA's September 2024 five-year review confirmed the remedy still protects human health and the environment. Human exposure is currently under control across the entire site. However, groundwater migration is not yet stabilized, so monitoring continues to track movement and keep contamination within the original zone. The review also identified needed improvements: adding an extraction well to restore pumping capacity to around 300 gallons per minute, installing extra wells to address dense non-aqueous phase liquid (DNAPL) contamination at the Coke Plant and Lagoon Area, and sampling groundwater for per- and polyfluoroalkyl substances (PFAS). Land-use restrictions remain in place, blocking residential and other incompatible uses. As of December 2024, nine businesses operate on the site, employing 125 people and generating about $24.9 million in annual sales.
Community members with questions can contact the EPA's Community Involvement Coordinator or Remedial Project Manager.
