COPPER BASIN MINING DISTRICT, OPERABLE UNIT 1
COPPERHILL, POLK COUNTY, TENNESSEE
BACKGROUND AND STATEMENT OF ISSUES
The U.S. Environmental Protection Agency - Region IV (EPA) asked the Agency for Toxic Substances and Disease Registry (ATSDR) to assess the public health impact of environmental contamination at the Copper Basin Mining District site. This consultation will address only the human health impact of contamination at the site. Although mining activities and related contamination have dramatically affected the environment and biota at the site, these issues are outside the scope of ATSDR.The Copper Basin Mining District Site is located in Polk County, Tennessee. Commercial mining operations began in the region in the mid 1800s. A large complex mining and production facility operated in the basin for years and included mining, milling, floatation, roasting, smelting, and producing bulk chemicals (primarily sulfuric acid).
The subject area covers 30 square miles and includes the now defunct Tennessee Chemical Company (TCC) and other areas that have been impacted by mining activities. The TCC ceased mining activities in the basin in 1987 and declared bankruptcy in 1989. Much of the land formerly owned by TCC was auctioned off and is now in private hands.
The EPA divided the site into six operable units. This health consultation will address contamination in Operable Unit 1. The most prominent geophysical features in Operable Unit 1 include the Tailings Pond, Bura-Bura Mine, Hiawassee Mine, McPherson Mine and the headwaters of North Potato Creek and Bura-Bura Creek. Several other prominent features inside Operable Unit 1 (i.e.; the London Mill Flotation Plant and the Isabella and Eurkea Mines) are evaluated separately as Operable Units 3 and 4.
The Tailings Pond occupies an area of about 160 acres. It was created by damming Bura-Bura Creek and a portion of North Potato Creek. From 1945 until 1987, the Tailings Pond was used as a disposal area for mine tailings and waste products from the flotation process at the London Mill Flotation Plant (LMFP). In 1979, the London Mill Waste Water Treatment Plant was constructed to treat runoff water from the tailings pond that was being discharged to Bura-Bura Creek. Acid mine drainage from the McPherson and Eureka Mines is also treated at the LMWWTP.
In 1997, PRC Environmental Management, Inc., a contractor for EPA, conducted environmental sampling at the site. This consultation will focus on the results of this environmental sampling, since these data provide the most recent characterization of environmental contamination at the site.
Samples of waste materials, surface soil, sediment, and surface water were collected from the tailings pond and analyzed for metals and organic chemicals. The primary contaminants of concern detected in the environmental media were copper, lead, and manganese. The maximum concentrations of contaminants detected are presented in Table 1.
One surface soil sample contained lead at an estimated concentration of 1,100 parts per million (ppm). However, none of the other surface soil, sediment, or waste samples contained lead at a concentration in excess of 180 ppm. Therefore, lead contamination at the tailings pond does not appear to be widespread.
Table 1: Maximum concentrations of contaminants in environmental media in the
Tailings Pond (Operable Unit 1)(a)
|surface soil||2,200 J||1,100 JN||5,000|
(a) surface soil, waste, and sediment - parts per million (ppm)
surface water - parts per billion (ppb)
J - estimated value
N - presumptive evidence of presence of material