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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 requiring 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 and delivery of bottled water to residents with contaminated drinking water wells is ongoing. Excavation has been completed on eleven properties, backfilling is complete on nine of those. Residences with a child showing an elevated blood lead level were excavated first. Excavated soil thus far is 9,934 yd3. Eighty-seven wells have been found with lead contamination over the action level and bottled water is being offered to those residents.
Sampling of residential properties and drinking water wells will continue. Excavation of contaminated soil and delivery of bottled water is ongoing.
Seeding of peoperties excavated in the late fall and winter will take place in the spring.
An unusual amount of rain has fallen in the last month, accounting for eight days of missed work.
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