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Franklin County, Missouri, consists of 922 square miles located in the Ozark region of Eastern Missouri bordered by the Missouri River to the north. The county is known for steep hills, deep valleys, caves, springs, and sinkholes. The temperate climate of the area is known for hot summers and cold winters. According to the 2000 Census, approximately 101,579 people live in Franklin County. Because Franklin County is located in the very Northwestern portion of the Lead and Barite District of Southeast Missouri, it has been subject to light to moderate historic mining activities and potentially associated areas of residual contamination.
Lead mining areas were confined to the south central portion of the county where lead-bearing mineral deposits of the Cambrian and Ordovician age are located near the surface. Lead, iron, copper, and barite have been mined in the county since the 1800s and the area grew at its peak to include several distinct mines, the largest of which was Virginia Mine. During its operation, Virginia Mine produced more than 25,000 tons of lead. One hundred and seventy-seven mining sites have been identified by the Inventory of Mines, Operations, and Prospects (IMOP) in Franklin County and waste from these mining sites has the potential to be harmful to human and environmental health if not dealt with properly. The waste contamination concerns are primarily with lead, however may also include minerals containing arsenic, cadmium, and/or barium.
In 2006, the EPA START contractor conducted an Integrated Site Assessment (ISA) in Franklin County. In total, 117 residential properties were screened for lead, barium, cadmium, and arsenic contamination. Four properties were found to have lead soil levels above 400 parts per million (ppm), while 15 wells contained lead concentrations greater than the MCL of 15 parts per billion (ppb). In early fall of 2008, the sampling continued this time in the form of a pilot study to compare a couple of different sampling methodologies in terms of analytical accuracy/repeatability and cost-efficiency/time of effort for the methods. During this effort, two more contaminated wells were discovered, bringing the grand total in Franklin County to 17 thus far, and one more property had contaminated soil greater than 400 ppm, for a total of five in the county.
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