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The Washington 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 which require action are lead contaminated soils in yards, contaminated drinking water, and lead contaminated dust in homes along roadways.
The Washington County Lead District – Old Mines Site is located in a heavily mined region of eastern Missouri known as the Washington County Lead District. The Old Mines Site primarily includes residential areas within and around the communities of Old Mines, Kingston, Fertile, Tiff, and other smaller communities. It is only a portion of the larger Washington County Lead Mining District.
Mines in the Old Mines Area include the following:
Pfizer Kingston School
Mobar Star Mine
Milchem Whale-Scott Mine
AW Wood Mine
DeSoto Mining Company – Fertile Mine
Dresser Minerals Big River
Milchem Sun Mine
General Barite Blackwell
Dresser Minerals Mine #44
Dresser Minerals Racola
H&P Mining Company
General Barite Old Mines
Terrace Mines
Pfizer Arnault School
Dresser Minerals Breton Creek #3
Dresser Minerals Mine #11
NL Bariod Blackwell
Dresser Minerals Mine #6
In August 2005, EPA began an integrated assessment which included soil and groundwater sampling in the Old Mines area. During this sampling event EPA sampled the soil at 85 residences located on or near mining or mine waste disposal areas. Based on this data, approximately 47% of these residential properties had soils which exceeded 400 ppm and roughly 13% had soils which exceeded 1200 ppm for lead. EPA also sampled approximately 77 private drinking water wells in the Old Mines area beginning in August 2005. Of these 77 wells sampled, 7 exceeded 15 parts per billion (ppb) for lead, and one well exceeded 3030 ppb for barium, which exceeds the Maximum Contaminant Levels (MCLs) for lead and barium in drinking water.
Excavation of lead contaminated soil at the Old Mines Site began October 2. Properties with children showing an elevated blood lead level are being excavated first. The contaminated soil is being transported to a Doe Run owned mine tailings site that was permitted by the state to accept the contaminated yard soils. Sampling of drinking water wells continues with 549 wells sampled thus far. Of those sampled, eighty wells have been found with lead levels above the action level of 15 parts per billion (ppb). Bottled water is being provided to fifty-seven residences. Thirteen residences have declined.
Approximately 500 homes have yet to be sampled and EPA continues to attempt to gain access to complete the sampling.
EPA will continue to excavate residential properties with lead levels above 1200 ppm. EPA will continue to provide bottled water to those residences with drinking water lead levels above 15 ppb.
Clarify if barrier needs to be placed at the base of the excavation if the depth is two feet or greater and the lead levels are 1200 ppm or greater.
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