The discovery in drinking water of a chemical used as a degreaser has led the Loudoun County Department of Health to ask some homeowners to stop drinking water from private wells and offer free testing of 50 private wells in the vicinity.
During routine checks of private wells in the easternmost portion of Broad Run Farms, testers discovered unusual levels of trichloroethylene, or TCE, in a few wells. A check of county records led to the discovery that seven wells over the last 16 years have tested positive for higher-than-acceptable levels of TCE.
TCE is a colorless or blue liquid that smells like chloroform and is used to remove grease from auto parts. The Environmental Protection Agency has set an acceptable level of one part per billion of TCE in water; a Broad Run Farms well tested at 20 times that level in the worst case.
TCE consumption at that level has no short-term effects, said Dr. David Goodfriend, director of the Loudoun County Health Department.
"Over years or decades, it might cause a problem," Goodfriend said.
"Some people who are exposed to TCE at certain dosages for a number of years have an increased risk of getting cancer," said Richard Doucette, waste program manager for the Virginia Department of Environmental Quality, which is assisting the health department in its investigation of the wells.
THE CONTAMINATED wells are all adjacent to the 30-acre Hidden Lane landfill, which closed in 1985 — prior to Virginia's solid waste regulations, passed in 1988.
"The landfill next to it is thought to be the source," Doucette said. "We can't say that is the true source until more studies are done."
Goodfriend concurred. "We don't know of any other source," he said.
According to Doucette, TCE is not a common contaminant. The easiest way to treat TCE contamination is to "capture" it by treating landfill material with an air stripper or a granulated carbon stripper and reinjecting it in the ground.
Goodfriend stresses that the problem is very localized. The health department is offering to test 50 wells near the landfill the weekend of March 6. Landowners with potentially affected wells have been contacted.
For landowners with a positive result, Goodfriend recommends avoiding drinking the water until after installing a filtration system. Bathing in TCE-contaminated water is not considered a risk, according to the health department.
The health department and DEQ will enter talks with the landfill owners, said Doucette, and determine how to rectify the situation. If the landfill is determined to be the source, it is required to act.
For more information about TCE, call the Loudoun County Health Department at 703-771-5512, e-mail firstname.lastname@example.org or visit http://www.loudoun.gov/issues/tcefacts.htm.