Fairfax Supervisor Audrey Moore (D-Annandale) told her colleagues on the Fairfax County Board this week that she didn't know "whether to laugh or cry" when she received a letter from one of her constituents questioning the safety of drinking water in her district and complaining about the management of the county's drinking water supply.

To Moore, whose hard-line stance on environmental issues often makes her a lone vote on the Fairfax board, it was ironic, to say the least, that the critical letter should come to her.

"It just killed me," Moore said. "But the guy was concerned and he deserves some answers. We do have a problem."

The letter from the Annandale resident resulted from an article he read in this month's issue of Good Housekeeping magazine. The article said the Environmental Protection Agency rated Annandale's drinking water supply as one of 10 in the United States with extremely high levels of chemical contamination that is potentially cancer-causing. The EPA had rated 113 drinking water supplies around the country, and the magazine listed the 10 jurisdictions with the worst ratings.

What enraged Moore was that the poor rating really applied to all drinking water that comes from the Occoquan Reservoir and serves approximately 600,000 people in Fairfax County, Prince William County and Alexandria. The EPA had measured the drinking water near its source in the Occoquan but used the former Annandale mailing address of the Fairfax County Water Authority to define the location.

"It's unfair that Annandale should be singled out like this," Moore said. "The same problem affects the whole county."

As a result of her complaints, the board unanimously decided Monday to send letters explaining the error to the EPA and Good Housekeeping.

The magazine reported that an EPA study done about a year and a half ago found that Annandale's drinking water (actually all drinking water from the Occoquan) contained a concentration of organic materials suspected of causing cancer that equaled 200 parts per billion parts of water. The group of organic materials, called trihalomethanes, includes chloroform.

Since the study was done, said Fairfax County Water Authority spokesman James Warfield, the trihalomethane (THM) level in the water has been somewhat reduced due to changes in water treatment and more sophisticated water testing methods.

"It was true, we did have a problem a couple of year ago," he said. "But the counts now are nowhere near 200 parts per billion."

In March, the highest THM count was found in drinking water in the Dumfries area at 150 parts per billion. The lowest was in Alexandria at 79 parts per billion, and Annandale water showed 82 parts per billion, Warfield said.

He added that the counts all are probably over 100 parts per billion now, because the THM level increases in warm weather.

The EPA has established 100 parts per billion gallons of water as the maximum THM level that should be allowed in drinking water supplies and is in the process of trying to get the standard put into law.

The Fairfax County Water Authority is expected to "reach a concensus" at its Aug. 3 meeting on its reaction to EPA's recommended standard and other water quality regulations the agency is proposing to reduce trihalomethanes, Warfield said.

Previously, members of the water authority board have not been able to agree on the EPA's proposed regulations.

"Even if some board members feel that 100 parts per billion is not a good standard, nobody wants to vote against it because it looks like you're voting for cancer," Warfield said.

The Board of Supervisors this week voted support for the EPA standards, a move that Warfield said probably will greatly influence the water authority's response to the EPA.