Koppers Co., Inc. (Texarkana Plant)

Overview

The Koppers Co., Inc. Texarkana Plant is a 62-acre former wood treatment facility in Texarkana, Texas. Operations ran from 1903 to 1961 and left behind widespread contamination. The site was added to the EPA's National Priorities List (NPL) in June 1986. A residential subdivision with 79 homes was built on the northern portion of the property in 1964, which made early cleanup actions urgent.

Contaminants found in soil, groundwater, surface water, and sediment include polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, anthracene, pyrene, and benzo[a]pyrene. Metals include arsenic, chromium, copper, lead, and zinc. Volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylene are also present, along with pentachlorophenol and tetrachlorodibenzo[b,e][1,4]dioxin (TCDD). No measurable contamination was detected in the public water supply.

Cleanup has happened in several phases. Between 1985 and 1986, clean soil and sod were placed in yards of 24 affected homes. The U.S. Army Corps of Engineers completed the buyout and relocation of all affected residents by 1993. Around 3,000 tons of contaminated soil were removed and replaced by 1996. A groundwater and dense non-aqueous phase liquid (DNAPL) treatment system was built and finished in 2002. In-place treatment and natural attenuation of DNAPLs are ongoing. The site has been divided into three operable units covering home purchases and relocation, soil removal, and groundwater. Physical construction of the cleanup is complete across the entire site.

Human exposure is currently under control sitewide, with no unacceptable exposure pathways identified. Contaminated groundwater is stabilized and not discharging unacceptably to surface water. The site is not yet ready for full anticipated reuse, as some cleanup goals and land-use restrictions have not been completely achieved. Zoning now limits the land to commercial use only. Protectiveness depends on keeping fencing in place, honoring deed restrictions on excavation and drilling, and continuing to monitor sediment and oily sheens. A groundwater remedial investigation is underway, with an estimated finish date of August 2025. The most recent five-year review was completed in September 2021, and the next is expected between September and November 2026. The site is estimated to be ready for reuse between June and August 2028. The City of Texarkana plans to develop a baseball park on the property once cleanup allows it.

Community members with questions can contact the EPA's Community Involvement Coordinator. The Texas Commission on Environmental Quality (TCEQ) also oversees the site and has staff available for both technical and community relations questions.