Mid-Atlantic Wood Preservers, Inc. ran a wood treatment facility in Harmans, Maryland from 1974 to 1993. The facility used chromated copper arsenate, a preservative solution, to treat lumber. A storage tank spill and drippings from the wood-drying area sent arsenic and chromium into the soil and groundwater. A nearby private well became contaminated in 1978, with chromium levels reaching 195 times the federal drinking water standard. EPA placed the site on its National Priorities List (NPL) in 1986.
The contaminants of concern are arsenic, chromium, and chromium(VI), all found in surface soil. Groundwater beneath and downgradient of the site was also affected. EPA determined these substances posed unacceptable risks based on the amounts present and the potential for people or the environment to be exposed.
Cleanup work was finished by September 1993. Workers excavated contaminated soil for off-site disposal and consolidated remaining material on-site under a three-acre asphalt cap. An enlarged roof drip pad was built to prevent future dripping onto the ground. Institutional controls restrict land uses such as residential development to protect the cap and limit exposure to remaining contaminants. EPA deleted the site from the NPL in July 2000. The site reached "sitewide ready for anticipated reuse" status in 2006 and today hosts several businesses, including a boat repair shop, an indoor soccer facility, a trucking service, and a limousine rental business. One on-site business employed 150 people and generated about $6.7 million in annual sales as of December 2024.
Human exposure is under control. The asphalt cap blocks direct contact with contaminated soil, and current groundwater sampling shows no remaining unacceptable health risks. Contaminated groundwater migration is stabilized, with no unacceptable discharge to surface water. EPA continues monitoring to confirm contamination stays within the original area. Institutional controls, including zoning restrictions, remain in place because hazardous substances are still present at levels that do not allow unlimited use and unrestricted exposure.
EPA conducts five-year reviews to make sure the cleanup keeps protecting public health and the environment. The most recent review was completed in August 2023 and confirmed the remedy is still working as intended. The next review is scheduled between August and October 2028. Community members can get involved through EPA's Community Involvement Program. Site records are also available at the Severn Community Library in Severn, Maryland, or at the EPA Region 3 office by appointment.
