Industrial waste disposal at a former sand and gravel quarry in Elkton, Maryland left soil and groundwater contaminated with dozens of chemicals. The 150-acre site was added to the National Priorities List (NPL) in September 1983. Physical construction of the cleanup is now complete, and the site reached "ready for anticipated reuse" status on January 25, 2022. A five-year review is underway, with a final report expected by September 2026.
The site contains over 80 distinct chemical contaminants. Shallow groundwater holds heavy metals such as arsenic, cadmium, chromium, lead, and mercury, along with volatile organic compounds (VOCs) including benzene, trichloroethene, tetrachloroethene, and toluene. Deep groundwater contains several of the same VOCs plus phenol. Contaminants have also been detected in soil, sediment, surface water, and solid waste. Key health risks come from ingesting or touching these substances.
EPA is overseeing cleanup work conducted by responsible parties. The site is divided into operable units targeting shallow groundwater, deep groundwater, and soils and source areas. A groundwater extraction and treatment facility built in 1996 has treated over 331 million gallons of groundwater as of July 2021. About 57,500 tons of heavily contaminated soil were treated on-site using thermal desorption in 2010, and 10,000 more tons were shipped off-site to approved hazardous waste facilities. A bioventing system ran from 2011 through 2016 to help break down remaining soil contaminants.
The final phase of groundwater cleanup began in March 2020. Chemical oxidation, finished in April 2020, cut contaminant concentrations by 93%, focusing on 1,4-dioxane and chlorobenzene. Bioremediation injections started in September 2021 to reduce contaminant levels further. Groundwater extraction, treatment, and residential well sampling will continue until groundwater restoration goals are met. EPA performance measures show human exposure is currently under control, with no unacceptable exposure pathways identified. Groundwater migration is stabilized, with no unacceptable discharge to surface water.
Community members can get involved through EPA's Community Involvement Program. Fact sheets from March 2020 and August 2021 are available with site updates. Site documents can be reviewed at the Cecil County Library at 301 Newark Avenue, Elkton, MD 21921, or at EPA Region 3 at 1600 John F. Kennedy Boulevard, Philadelphia, PA 19103. Call ahead to schedule a visit. For questions about the five-year review or to share information, contact the site's community involvement coordinators or the remedial project manager.
