Unwell water in South Carolina. (Metal Toxicity).

Last February, South Carolina health and environmental officials found that three wells used for drinking water by residents in the Simpsonville area contained fifty times the federal government's 30 ppb maximum allowed level of uranium. In the next seven months, the state tested 948 public and private wells in Pickens, Greenville, and Oconee counties for uranium and found that 92 of the 616 private wells and 7 of the 327 public wells tested also didn't meet the federal drinking water standard for uranium. Public wells are sunk by the state and must meet stricter federal and state regulations.

"The South Carolina Department of Health and Environmental Control's [DHEC] Bureau of Environmental Services is still studying the problem," says Stephanie Brundage, district health director for the Appalachia II Public Health District. "We really don't know how extensive it is."

The uranium contamination is from a natural source and not the result of industrial pollutants. Uranium occurs in most rocks, usually in concentrations of about 2-4 ppm, and is relatively common in the earth's crust. Geologists believe the contamination arose because uranium is a naturally occurring radioactive metal present in bedrock formations of the South Carolina Piedmont region. "Similar geological features extend from Alabama to Virginia, so we can't rule out the possibility of similar uranium concentrations in other states," says David G. Baize, an official with DHEC's Bureau of Water.

Last July, DHEC released the results of urine analyses conducted on 105 people who had been drinking the contaminated well water; 94 of them had elevated levels of uranium that exceed the state and federal maximum contaminant level (MCL) for public water, which is 30 ppb. Although this MCL does not govern private wells, it is used as a benchmark to gauge well water quality, says Robert Olive, an environmental scientist with the U.S. Environmental Protection Agency (EPA) Water Management Division, Region IV, in Atlanta. "We have advised people with contaminated wells to stop drinking the well water or to filter their water to remove the uranium," says Brundage.

As a heavy metal, uranium can cause health problems. "Uranium doesn't give off much radiation, and it's not known as a carcinogen, but it's a heavy metal, and so it can have an effect on the kidneys," says Daphne Neel, who is assistant bureau chief of the DHEC Bureau of Environmental Services.

Brundage adds that South Carolina health officials don't expect serious health effects to result from the uranium contamination. "In fact," she says, "we haven't been able to identify any people who have developed kidney problems."

The state of South Carolina has earmarked $5.64 million to deal with the problem. The state plans to spend $2 million for a geologic study, $2 million on infrastructure (mostly public water lines), $1.25 million for sampling, analysis, and public education, and $500,000 for a public health investigation. The South Carolina congressional delegation is seeking $1.5 million from the EPA to help the state study the local geology to identify reasons for the contamination.

Meanwhile, researchers at Clemson University are studying filtration systems to see how effective they can be in ensuring the safety of the water supply. "I have done a lot of experiments, and the use of activated carbon filters seems to work the best," says Jim Navratil, a professor of environmental engineering and science at Clemson. "They cost a few hundred dollars, only have to be changed occasionally, and can be thrown out with the regular household waste."

South Carolina officials have also been encouraging residents in the contaminated area to have their well water tested. "For a twenty-five dollar charge, they can be sure that their drinking water isn't going to make them sick," Brundage says.