Water toxins at unsafe levels in D.C. tap water samples

WASHINGTON - A study released Thursday found unsafe levels of toxic chlorine pollutants in 40 percent of District of Columbia tap water samples tested during a spring chlorine surge.

The Environmental Working Group conducted the tests from May 1 to 4, at the end of a month long "chlorine burn" the Washington Aqueduct conducts annually to remove sludge and sediment from pipes. The tests were done at private homes, a school, the U.S. Capitol and the Environmental Protection Agency.

The national nonprofit organization measured levels of toxins that could cause cancer, reproductive problems and developmental delays in children. The toxins are a byproduct of the reaction between chlorine and organic matter in Potomac River water.The Washington Aqueduct began conducting the annual "chlorine burn" after switching from chlorine to the less-potent chloramine to treat water at the EPA's urging in 2000. Many utilities have found that the chloramines are not strong enough to kill microbes throughout their vast distribution systems.

The Environmental Working Group recommends that the U.S. Army Corps of Engineers, which operates the aqueduct, switch to carbon filtration to remove more chlorine byproducts. Residents are urged to use home water filters until then.
Washington Aqueduct General Manager Thomas P. Jacobus said the study results were probably temporary. He said D.C. water meets EPA safety standards because test results for the concentration of chlorination compounds are averaged over the year.

The EPA's regional office in Philadelphia is responsible for overseeing the city's water quality. A water official there said EPA regulations focus on limiting risks from long-term exposure, not short-term spikes.
"A couple of months of higher numbers - we don't have any information that shows conclusively that that causes health risks," Rick Rogers said.But the Environmental Working Group said the district's water issues reflect national water treatment problems."It's time to face up to the fact that it's impossible to take the Potomac River in its current polluted state, put it through a very old, rudimentary treatment system and get water that people can safely drink," said the group's executive director, Richard Wiles.The Washington Aqueduct provides water to 1.1 million customers in the district as well as Arlington and Falls Church in northern Virginia.