Ouachita Nevada Wood Treater

Overview

The Ouachita Nevada Wood Treater is a former wood-treating facility covering about 5 acres near Reader, in Ouachita County, Arkansas. It operated from 1946 to 1987. The site was added to the EPA's National Priorities List (NPL) in May 2000, marking it as a priority for federal cleanup. It remains on the NPL today.

The facility treated wood with pentachlorophenol (PCP) and other chemicals that contaminated both soil and groundwater. EPA has identified 32 contaminants of concern at the site. These include metals such as arsenic, chromium, and copper. Organic compounds include polycyclic aromatic hydrocarbons (PAHs) like benzo[a]pyrene, as well as naphthalene and pentachlorophenol. Volatile organic compounds such as toluene and xylene were also found, primarily in groundwater.

EPA took its first major action from March to June 2000, excavating about 4,065 tons of contaminated soil and removing tanks, drums, and impoundments. A formal cleanup plan, called a Record of Decision, was signed in September 2005. That plan called for recovering light non-aqueous phase liquid (LNAPL), using enhanced bioremediation, installing a slurry wall along the western property boundary, and applying monitored natural attenuation. Institutional controls were put in place to restrict use of shallow groundwater. Construction of the cleanup work finished in September 2006. In 2016, contamination was found west of the slurry wall. EPA responded by testing in situ chemical oxidation (ISCO), a process that breaks down contaminants in place using chemical reactions. Pilot studies run from July to November 2020 showed most wells reached cleanup targets after treatment. An additional investigation into the source areas and groundwater began in September 2022.

Human exposure at the site is currently under control, meaning no unacceptable pathways exist for people to contact contamination. Groundwater migration is also under control, with contaminated water stabilized in its original area. The most recent five-year review, completed in August 2021, confirmed the remedy remains protective. The next review is estimated between August and October 2026. The site has not yet been deleted from the NPL and has not achieved sitewide readiness for full anticipated reuse.

Community members with questions can contact the EPA Community Involvement Coordinator or the Remedial Project Manager. For state-related questions, contact the Arkansas Department of Environmental Quality (ADEQ).