Shaw expands TCE cleanup efforts Published April 12, 2006 By 2nd Lt. Bryan Cox 20th Fighter Wing Public Affairs SHAW AIR FORCE BASE, S.C. -- Shaw is expanding its environmental cleanup effort of a once-common industrial chemical found in groundwater beneath the base and off the western edge. The 20th Civil Engineer Squadron is drilling additional extraction wells to enhance removal of the chemical trichloroethylene. Since 1997, the 20th CES has removed more than 1,300 pounds of TCE from groundwater, and reduced the off-base affected area from 211 acres to 105. "Shaw is committed to its environmental restoration effort, and we have a comprehensive plan that has already had great success in reducing TCE contamination," said Col. Michael Beale, 20th Fighter Wing Vice commander. Base drinking water is treated and is completely safe to drink, said Mr. Zollie Green, 20 CES project chief. The 20 CES employs a pump-and-treat method that pumps up to a million gallons of water per day from the aquifer beneath Shaw and treats it to remove TCE before allowing it to flow back into the Wateree River, said Mr. Green. The base has treated a total of more than 500 million gallons of water using this method. Shaw maintains and operates six drinking water wells to supply the potable water needs of the base. These six wells draw water from the Upper Black Creek, Lower Black Creek, and Upper Middendorf aquifers. Each well is monitored for TCE. TCE-affected water lies in an aquifer approximately 150 feet below the western edge of the base. The only way to come in contact with this water is by pumping it from a well, said Mr. Green. According to Mr. Green, the 20 CES has conducted well surveys from 1992 to the present to notify landowners off-base that may be using contaminated wells that they should cease doing so. It's unclear exactly how the chemical entered the groundwater beneath Shaw, but before TCE was banned by the Air Force in 1986 it was commonly used as a solvent to degrease metal and it also is a byproduct of dry cleaning. The South Carolina Department of Health and Environmental Control first discovered TCE in groundwater in an off-base mobile home park in 1989, and the Air Force took the lead for cleanup in 1990. South Carolina DHEC samples the wells at Shaw for chemical contamination. The most recent sampling for TCE took place in 2005 and returned a TCE content of 1.9 parts per billion. The maximum allowable contaminant level for TCE in drinking water is 5.0 parts per billion, which places Shaw's drinking water well within the safe range. As part of the ongoing cleanup, Shaw recently began a thorough well survey to ensure that no one is using well water that may be contaminated above the safe exposure limit. This well survey was mailed to approximately 120 landowners whose property is within 1,000 feet of the largest known contaminated plume. The base also invited these landowners to the semi-annual Restoration Advisory Board meeting on February 6 to receive information on the clean-up progress. "This meeting was a great opportunity for us to listen to public concerns and also to ensure we provide as much information as possible," said Col Beale.