Critics of Water Report Fight Back

July 19, 2007
Darci Marchese, WTOP Radio
WASHINGTON - Concerns were raised about the safety of tap water in the Washington area in a recent environmental report. On Thursday, critics of that report fought back. Thomas Miller, a director at the University of Maryland, says there's no scientific proof that the levels of chemical by-products found in tap water in D.C. and northern Virginia pose any health danger. "If you drive on the D.C. beltway, don't worry about your drinking water," says Miller, who is also a former water quality specialist. Rich Giani, a water specialist for the D.C. Water and Sewer Authority, says the water is perfectly safe to drink. "If there was an issue we'd obviously be reporting it to everybody out there."

The report released by the non-profit Environmental Working Group raises concerns about the long-term health effects of drinking the tap water, questions the Washington Aqueduct's decision to change how it disinfects drinking water and calls for more protection of the Potomac River. For the 1.1 million people who drink the water, the report recommends the use of carbon filters to further reduce contaminants. In 2000, the Washington Aqueduct changed how it disinfects the region's drinking water, switching from treating it with chlorine to treating it with chloramines. Both chlorine and chloramines are used to keep water free of deadly pathogens. But the report finds that the chloramines produce an "entirely different set of byproducts" than chlorine and not enough is known about the long-term health effects of those toxic byproducts. The report says: "There is no question that the wide scale use of chemical disinfectants in public drinking water supplies has been one of the greatest public health advances in the twentieth century.

Over time, however, we have become overly reliant on chemical treatment of tap water as we have simultaneously failed to protect and clean up the sources of this water. This has placed water purveyors like the Washington Aqueduct in an intractable bind where the process of purification of polluted source water exposes consumers to unnecessarily high and potentially unsafe levels of toxic chemicals formed during the treatment process." Environmental Working Group took 18 water samples from schools, homes, parks and buildings, including the U.S. Capitol, and tested them for haloacetic acids (HAAs) and trihalomethanes (THMs), chemicals formed during the disinfection process. The samples were taken at the end of month-long "chlorine burn" that's conducted annually to remove sediment and sludge from the Washington Aqueduct's pipes.

The burn temporarily raises toxin levels in the water. Tom Jacobus, general manager of Washington Aqueduct, says under Environmental Protection Agency standards, water samples must be taken during each season of the year, since they fluctuate -- especially in warmer weather. Toxic levels were "well below the federal standards," Jacobus says.
But the Environmental Working Group's water samples revealed that the HAAs were at their highest levels since 2001.
"Forty percent of the samples we took in May of this year had levels of these chlorination byproducts over the annual federal health limit," says Richard Wiles, executive director of the Environmental Working Group.
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