The D.C. Water and Sewer Authority has asked a Superior Court judge to dismiss a class action lawsuit against the agency over its management of lead contamination of some drinking water, arguing that a court order would impose burdensome and unnecessary costs.

In a lengthy court briefing filed this week, WASA attorneys argued that the agency already has taken numerous steps to protect public health until it can solve the lead leaching problem.

The documents are WASA's first public response to a lawsuit filed two months ago on behalf of two D.C. families by Paul, Hastings, Janofsky & Walker, a law firm. That suit asked the court to order WASA to take immediate steps -- including distributing water filters or bottled water -- to protect every city resident whose home has water with high lead levels.

WASA attorneys said the agency would have to test the water at every household or give each residence a free filter, which is unfeasible. Thus, the agency has focused on the most vulnerable populations and has distributed about 27,000 filters to homes with lead service lines.

WASA is uncertain what kind of service lines provide water to another 22,000 homes. But the agency, at the urging of city and congressional leaders, offered free water tests to those residents and promised a free water filter to any home that has water with excessive lead levels.

A court order is unnecessary, the attorneys said, because it would impose excessive costs on a quasi-independent public agency whose funds are drawn from ratepayers. According to WASA's calculations, court-ordered remedies, including water tests and filters, for all 345,000 WASA households could cost $48 million in six months, attorneys said. That could add $60 a month to each resident's water bill.

Furthermore, the health risk from the water has not been established as significant, the attorneys said.

"The requested injunctive relief would have a detrimental effect on WASA's ability to quickly and effectively complete the other (and, in WASA's view, more beneficial) aspects of its program to reduce lead levels in the District's water supply," the attorneys wrote. An injunctive court order "would not only cause serious financial problems for WASA in the short-term, but could also damage WASA's long-term financial health."

A representative for Paul, Hastings said yesterday that the firm intends to file a response to WASA's briefing by Wednesday.

When they filed the lawsuit, the lawyers maintained that WASA is putting the burden of proof on most city residents to show that their water has high lead levels before the utility will give them a filter. Instead, the court should require WASA to prove a house does not have an excessive lead level before it can deny a filter, the Paul, Hastings lawyers argued.

In making their case, WASA attorneys lauded the agency's handling of the lead problems since the agency officially reported high lead levels to the Environmental Protection Agency in 2002.

"WASA has consistently surpassed the regulatory requirements regarding public education and outreach," they wrote.

Many D.C. residents and government leaders, including Mayor Anthony A. Williams (D), have complained that WASA failed to alert the public promptly to the extent of the lead problems and potential health risks. The EPA, in a preliminary finding, said it appeared that WASA violated federal law by failing to follow some federally mandated disclosure regulations. The EPA has not issued a final ruling.

But WASA attorneys said the agency sent brochures to residents and ran advertisements in the local media that mentioned the lead problem.

Noting that congressional and city leaders, as well as reporters, have debated the agency's handling of the lead crisis, WASA attorneys wrote that "in this cacophony of public comment, truth, reason and objective analysis have sometimes been drowned out by a chorus of hyperbolic, oversimplified sound-bites."