Fairfax tops others in tap water report

A report by an environmental group says that the Fairfax County Water Authority is among the best in the nation at keeping pollutants out of tap water -- and that a utility serving Montgomery and Prince George's counties is worse than average.

The report, released Saturday by the Environmental Working Group, ranks Fairfax Water eighth out of 100 large water utilities for its success in eliminating trace-level chemicals from fertilizer and pesticides and chemical leftovers from the water-treatment process.

It ranks the Washington Suburban Sanitary Commission 82nd, saying tests had shown higher levels of these chemicals. The group did not rank the Washington Aqueduct, the utility that provides water to the District and Arlington County, saying it had provided incomplete records.

At none of these utilities did tap water violate Environmental Protection Agency standards. And all of them said there is no reason for customers to worry or to filter their tap water before drinking it. The utilities addressed the report Friday, before they had seen the data.

"We've never had any drinking-water violations," WSSC spokesman Jim Neustadt said. "Our water is perfectly safe to drink."

But the environmental group said that some EPA standards are lax and that even tiny amounts of pollution can be harmful over years of consumption. It said that samples from all three of the Washington area's big water utilities had at times exceeded pollutant levels posing a cancer risk of 1 in 1,000,000, if the water was consumed over a lifetime.

"This is water that meets all federal standards, but it still contains residues" of some pollutants, said Jane Houlihan, senior vice president for research at the group. Houlihan recommends that WSSC customers filter their water and says others should not rule it out.

The group examined data from 20 million tests of tap water conducted across the United States since 2004. Nationally, 92 percent of utilities met EPA standards, the group said. But the group also said it was concerned about the 8 percent out of compliance -- and by the fact that the EPA has not set standards for several dozen chemicals commonly found in water.

"What that means is that we can't say for sure that tap water is safe," Houlihan said. An EPA spokesman said Friday that his agency had not yet seen the report.

Locally, the test results did not address the District's problems with lead in tap water or the hormone-mimicking pollutants that might be harming fish in the Potomac River, which is a major source of drinking water.

The group found traces of chemicals that are byproducts of the disinfection process in water from all three major Washington area utilities. Most treatment plants add chlorine-based chemicals to their water after it has been filtered to kill remaining germs. But sometimes the chemicals react with others and form new pollutants, which research has linked to cancer, the group said.

In most tests, the pollutants were found only in tiny amounts, measured in parts per billion. In samples from Fairfax Water and from the utility that provides water in Arlington and the District, the tests showed these chemicals were present -- but did not exceed the EPA's recommended limits.

In suburban Maryland, the study showed that WSSC water exceeded federal standard for the byproducts in two months since 2004. But the results did not violate EPA rules, which are based on annual averages.