Koppers Co., Inc. ran a wood treating facility in Morrisville, North Carolina from 1968 to 1975. Wastewater from that operation contaminated soil, groundwater, and surface water. The site was added to the Superfund National Priorities List (NPL) in 1989. EPA and the state of North Carolina have overseen cleanup led by the potentially responsible party, Beazer East, Inc.
Contaminants of concern include dioxins and dibenzofurans, 2,4-dichlorophenol, pentachlorophenol, and phenol. These have been found in groundwater, soil, and surface water across the site's one operable unit, OU01. Health risks come from ingesting or touching contaminated materials.
Major cleanup work was completed by the mid-1990s. That work included removing and incinerating 775 tons of contaminated soil off-site, backfilling two on-site ponds with clean soil, installing a groundwater pump-and-treat system, and mitigating wetland loss. EPA partially deleted the site from the NPL in 1997 after construction of the remedy was finished. A 2012 update to the cleanup plan added chemical oxidation as an in-situ treatment method and modified institutional controls.
Despite that progress, dioxin remains a concern. A 2012 EPA reassessment of dioxin toxicity set lower protective levels than those used during the original cleanup. A 2014 soil sampling study confirmed that dioxin and furan concentrations in some surface soil exceed direct contact screening levels for commercial or industrial use. The September 2022 Five-Year Review found the site still needs groundwater and land use institutional controls, a dioxin risk assessment for industrial use, and a decision on addressing elevated dioxin in the former lagoon and process area. A new combined remedial investigation and feasibility study for OU01 began in November 2024, with completion estimated between November 2027 and January 2028. The pump-and-treat system continues to operate, and EPA plans to issue an action document on groundwater contamination and additional source areas. The site has not yet achieved sitewide ready-for-reuse status. One business, Unit Structures, Inc., currently operates a wood processing facility on part of the site.
Community members can stay involved through public notices, public meetings, and interviews that EPA conducts throughout the cleanup process. The most recent Five-Year Review was published in September 2022, and the next is estimated for completion between August and October 2027. Physical records are available at the Morrisville Chamber of Commerce at 260 Town Hall Drive.
