Mound Plant (USDOE)

Overview

The Mound Plant in Miamisburg, Ohio operated as a research, development, and production facility for U.S. weapons and energy programs starting in 1948. It was added to the National Priorities List (NPL) in 1989 after volatile organic compounds (VOCs) were found in groundwater used for production and drinking water. The EPA (Environmental Protection Agency) and DOE (Department of Energy) signed a Federal Facilities Agreement in 1990 to coordinate cleanup. The DOE owns the facility and holds primary responsibility for remediation, while the EPA serves as the lead regulatory agency.

Contaminants are present in soil, groundwater, leachate, and soil gas. VOCs include trichloroethene, tetrachloroethene, benzene, and vinyl chloride. Heavy metals such as lead, cadmium, arsenic, and chromium are also present. The site contains radioactive materials including plutonium-238, tritium, strontium-90, and multiple uranium, thorium, and radium isotopes. Pesticides, dioxins, polycyclic aromatic hydrocarbons (PAHs), and other industrial chemicals round out the list of contaminants of concern.

Cleanup work included pumping and treating contaminated groundwater, soil vapor extraction, landfill excavation, and removal of radioactive and petroleum-contaminated soils from several areas. The DOE received $50 million in congressional and economic stimulus funding, and the overall cleanup cost reached $1 billion. Construction was completed in 2009, and the site achieved ready-for-anticipated-reuse status in September 2012. Groundwater treatment and monitoring continue today. Institutional controls prohibit residential use and restrict installation of drinking water wells in affected areas. Several parcels have been transferred to the Miamisburg Mound Community Improvement Corporation and redeveloped as the Mound Business Park.

The most recent five-year review, completed in September 2021, confirmed that cleanup actions protect public health and the environment. Human exposure is under control, and contaminated groundwater migration has been stabilized with no unacceptable discharge to surface water. The site has not yet been fully deleted from the NPL. The next five-year review is estimated between September and November 2026.

Community members can contact the EPA Community Involvement Coordinator or Remedial Project Manager assigned to the site. Additional agency contacts at the Ohio EPA and DOE are also available. The Administrative Record is accessible through the DOE as the lead agency and through the site's Public Information Repository.