Patuxent River Naval Air Station sits on a 6,400-acre peninsula in Lexington Park, St. Mary's County, Maryland. The Navy added it to the EPA's National Priorities List (NPL) on May 31, 1994, after historical landfills and disposal areas released hazardous chemicals into soil, sediment, groundwater, and surface water. The site is divided into 51 operable units, each addressing a specific contaminated area or contamination type. Construction is not yet complete across the whole site, and it has not been deleted from the NPL.
More than 100 chemical substances have been identified as contaminants of concern. Volatile organic compounds (VOCs) such as tetrachloroethene, trichloroethene, and vinyl chloride appear in groundwater near a former sanitary landfill, a dry cleaning facility, and a tire shop. Heavy metals including arsenic, lead, cadmium, chromium, and beryllium contaminate soil and groundwater in several areas. Pesticides such as DDT and its breakdown products, aldrin, dieldrin, and endrin are found in soil and sediment near a former pesticide shop. Polychlorinated biphenyls (PCBs), specifically Aroclor 1260, are present in soil and sediment at transformer storage and boatyard areas. Some areas also contain unexploded ordnance.
The U.S. Navy is the lead agency responsible for cleanup, with the EPA overseeing compliance with federal requirements. Several areas have been remediated. A landfill cap and gas collection system were installed at Site 11. Soil excavation at the former Pesticide Shop was finished in 2012. Sites 1 and 12 received soil covers and shoreline stabilization, completed in 2002. Shallow groundwater treatment for chlorinated solvents began at the Tire Shop in July 2017 and is expected to run 10 to 12 years. Work at a dry cleaning facility finished in December 2010, and marsh remediation was completed in December 2008. Some operable units, including drum disposal areas and unexploded ordnance sites, have estimated completion dates ranging from 2027 to 2028.
Human exposure is currently under control, meaning assessments show no unacceptable pathways for people to contact contamination at this time. Groundwater migration status remains unclear due to insufficient data. The most recent five-year review was completed in April 2024. Five-year reviews are conducted by the Navy and EPA to confirm that cleanup remedies protect public health and the environment.
Community members can get involved through the public Restoration Advisory Board (RAB), which holds meetings where attendees can learn about the site and remediation progress. The RAB also maintains a community outreach webpage with meeting minutes and additional information. The EPA encourages early and meaningful participation throughout the cleanup process.
