The Jefferson County Lead District Site consists of high concentrations of lead contamination from mining. The ore would normally be hauled from the mines to the concentrators (also known as mills) where it was formed into lead concentrate. Lead concentrate at the site was/is derived from the physical concentration of lead sulfide ore and is typically 70 to 80 percent (700,000 to 800,000 parts per million [ppm]) lead sulfide.
The primary problem areas at this site that require action are lead-contaminated soils in yards, drinking water wells contaminated with metals, and lead-contaminated dust in homes along the roadways.
EPA has documented total lead concentrations in soil in residential yards at levels exceeding 1,200 ppm. EPA has currently identified 22 residential yards in Jefferson County that exceed 1,200 ppm. In addition, EPA has sampled numerous mining areas and mine waste disposal areas that had soil concentrations exceeding 1,200 ppm. Drinking water samples collected by EPA indicate a significant release of heavy metal contaminants, particularly lead, into the groundwater. EPA sampling documented 36 private drinking water wells that exceeded 15 micrograms/liter (ppb) for lead. Of those 36 wells, 16 were greater than 30 ppb for lead and two wells exceeded 5 ppb for cadmium.
