EPA Superfund Site
BIG RIVER MINE TAILINGS/ST. JOE MINERALS CORP.
MO | EPA ID MOD981126899
About this site’s exposure pathways: As of June 2025, the Big River Mine Tailings superfund site is considered 'Current Human Exposure Not Under Control' because lead-contaminated yard soils and sediment remain unaddressed. Contaminated soil and sediments pose a direct contact and ingestion threat to young children and pregnant women. The planned activities to address this pathway were a series of removal actions to stabilize waste piles, replace highly contaminated surface soil in residential yards and child highuse areas, and complete two remedial actions to address remaining yard soils (OU 1) and watershed sediments (OU 2). A total of 7,130 yards have been sampled. Of those 5,179 had one or more areas > 400 parts per million lead. Over 2500 properties have been remediated where high levels of lead were found in residential properties or where children with elevated blood lead were identified. Six of the seven mine waste piles are stabilized. Surface water, sediment, and various forms of biota contain elevated concentrations of lead throughout the mining area. Fish in Big River have shown elevated concentrations of lead. Fish advisories have been in place at the site since 1981. EPA has worked with the St. Francois County Watershed Group, a group of local concerned citizens and other federal and state agencies, to help educate the community on the effects of lead contaminated soil, sediment, and surface water. Additionally, EPA plans to complete an Interim Record of Decision in 2025 to address lead-contaminated floodplain soil, surface water, and sediment in the Big River watershed from Leadwood to the confluence with the Meramec River. The planned activity to address the pathway for OU 1 is the continuation of ongoing remediation of lead contaminated soils. Additionally, the planned activities to address the pathway for OU 2 will be determined in the Interim Record of Decision for OU 2. Human Exposure is expected to be under control by 03/19/2057.