Ammonia to Be Used in Treating D.C., Va. Water

By Carol D. Leonnig

The U.S. Army Corps of Engineers will begin using ammonia next month to treat drinking water in the District and Virginia, a move that officials believe will reduce the risk of cancer linked to a lifetime of drinking chlorinated water.

The new treatment, which is to be announced today, also is expected to make drinking water smell less like a swimming pool when customers tilt a glass of it to their noses.

But the addition of a new treatment chemical will require some special precautions for people who own fish tanks and patients who need kidney dialysis treatment.

On Nov. 1, the Washington Aqueduct will begin using a compound of chlorine and ammonia to clean water from the Potomac River, the source of drinking water for the District, Arlington County and the Falls Church area. The change is geared to meet tougher federal water treatment rules that will go into effect in December 2001. The Corps of Engineers, which owns the aqueduct, is scheduled to announce the treatment plan at the Dalecarlia Water Treatment Plant in the Palisades neighborhood of Northwest Washington.

Tom Jacobus, the aqueduct chief, said he recognizes that some water users will worry about the addition of a new chemical. "Science has shown no evidence that this process is at all risky," Jacobus said. "The reason we're doing this is to lower the chronic health effects that might be linked to the presence of these disinfectant byproducts."

The compound, chloramine, was first devised for water treatment in the 1960s. Fairfax County has been using it for six years.
The U.S. Environmental Protection Agency recognizes chloramine as an appropriate strategy for reducing reliance on straight chlorine treatment. The EPA is lowering the maximum amount of chlorination byproducts it will allow in treated drinking water, from 100 parts per billion to 80 parts per billion.

Cynthia Dougherty, director of the EPA's Office of Groundwater and Drinking Water, said the stricter rules are needed because studies suggest a relationship between cancer and the byproducts of chlorine disinfection.
Those byproducts, called trihalomethanes, are formed when chlorine reacts with water that contains a large amount of organic material, she said. "We're regulating to be on the conservative side," she said.

Jacobus said most residents will not be affected by the new treatment. "Water users out to the west of us have been using this and never really noticed it," he said.

But fish will die if the chemical passes through their gills. To remove chloramine, tank water must be chemically treated.
Similarly, dialysis machines must be able to remove chloramine before treating patients with kidney problems.

Jacobus said hospitals, health care providers, pet shop owners and pet associations have been notified about the change.