EPA Superfund Site

WASHINGTON COUNTY LEAD DISTRICT - OLD MINES

MO | EPA ID MON000705027

About this site’s exposure pathways: As of March 2025, the Washington County Lead District – Old Mines site is considered Human Exposure Not Under Control because lead contamination in soil exceeds health based cleanup criteria at multiple residential and other high incidence child use properties.

Remedial investigation is ongoing for mine waste, sediments, floodplain soils and surface water. The lead concentration in private drinking water wells also exceeds the federal drinking water standard at numerous properties. Individuals may be exposed to lead contamination through the ingestion and inhalation of soil, dust, and groundwater. A Record of Decision (ROD) was finalized for residential soil in September 2011, with remedial action ongoing and anticipated to continue for many years. In addition, an Interim ROD for groundwater was finalized in September 2022 that will provide safe drinking water to residents with contaminated wells until a final remedy for the cleanup of groundwater is selected. A previous time-critical removal action provided point-of-use (POU) water filtration systems. More properties will be provided POU systems under the newly commenced remedial action for groundwater.

As part of its ongoing response activities, EPA meets with the public on a frequent basis and has provided a health education and outreach grant to the Washington County Health Department to promote habits to minimize exposures of residents to mine waste contaminated media at the site. Current Human Exposure is estimated to be under control by 2044.