The Koppers Co., Inc. Charleston Plant covers 102 acres along the Ashley River in Charleston, South Carolina. Wood treatment and phosphate fertilizer operations left behind widespread contamination in soil, sediment, groundwater, and surface water. EPA added the site to the National Priorities List (NPL) in 1994. A partial deletion from the NPL was completed in August 2022, though the site remains on the list overall.
EPA identified 26 contaminants of concern at the site. These include creosote, polycyclic aromatic hydrocarbons (PAHs), benzo[a]pyrene, arsenic, lead, dioxins, benzene, pentachlorophenol, dieldrin, chromium, and copper. Creosote was also found as free-phase non-aqueous phase liquid (NAPL) in groundwater. Arsenic and lead turned up in soil, sediment, and surface water. The site does not currently threaten people living and working nearby, because residents and businesses connect to the public water supply rather than using groundwater from the site.
The responsible party, Beazer East, Inc., carried out most of the early cleanup work. From 1997 to 2003, the company excavated and removed 22,000 tons of contaminated soil, placed caps over contaminated areas, rebuilt drainage ditches, and restored tidal marshes. Creosote and groundwater recovery systems operated from 2003 to 2010. In February 2018, EPA approved a Record of Decision Amendment authorizing an additional 30 million dollars in work to upgrade the remedy and support future mixed-use development, including residential use. Final remedial action ran from September 2019 through January 2022. EPA has determined that human exposure is under control, groundwater migration is stabilized, and all cleanup goals for current and anticipated future land uses have been met. The most recent Five-Year Review was completed in August 2023, with the next review estimated between August and October 2028.
Institutional controls limit land use at the site. A 2003 deed restricts parcels purchased by Ashley LLC, prohibiting residential development and groundwater use. A private developer is now pursuing a large mixed-use redevelopment project covering more than 200 acres along the Ashley River, including the Koppers site. EPA and the South Carolina Department of Health and Environmental Control are working with the developer to protect human health and the environment throughout that process. As of December 2024, two on-site businesses employed 50 people and generated about 9.8 million dollars in annual sales.
Community members can stay involved through public notices, meetings, and interviews that EPA conducts throughout the cleanup process. A public comment period on the partial NPL deletion proposal ran through May 2022. For questions, residents can contact EPA's Community Involvement Coordinator or Remedial Project Manager directly using the contact information below.
