District of Columbia Mayor Anthony Williams called on Congress to invest millions of dollars to upgrade the city’s 130-year-old sewer system as part of an overall cleanup of the Chesapeake Bay.

“The combined sewer system discharges over 2.5 billion gallon of untreated wastewater and precipitation into Rock Creek and the Anacostia and Potomac rivers,” said Williams, who also chairs the Chesapeake Executive Council, which sets policy for the Bay cleanup effort.

The problem of combined sewer overflows stems from the D.C. Water and Sewer Authority system originally constructed by the U.S. Army Corps of Engineers in 1870.

During periods of heavy rain, stormwater and wastewater mixes together, enabling raw sewage to flow unimpeded into waterways that ultimately drain into the Bay.

The system serves about one-third of the 61-square-mile city, including the area around the White House, Supreme Court and the Capitol complex.

While WASA is proceeding with its own $1.6 million capital improvement plan, Williams has requested that Congress approve funding for the project as a line item under the EPA’s budget for six to 10 years.

“For 2002, we will need $12 million,” said Williams, warning that without the money, the average district household could see their water and sewer bills triple over the next decade. The higher rates would be in addition to the projected 5 percent rate increases needed to finance WASA’s plans.

The agency wants to build a series of huge holding tanks under parkland near sewage outflow pipes. The system, similar to one installed in Richmond, VA, is designed to retain wastewater until it can be safely pumped to the 63-year-old Blue Plains Sewage Treatment Plant located on the Potomac River.

This could cost $1 billion over the next 20 years, said David J. Bardin, a WASA board member, adding that solving the problem is critical to cleaning up the Anacostia River, which flows into the Potomac. While the 8.4 mile long river is cleaner than it was 10 years ago, District officials have signed an agreement with 30 federal agencies to rehabilitate the area around the waterway with the goal of making it suitable for recreational use.

“Right now you don’t see anybody swimming in that river,” said Robert Boone, president of the Anacostia Watershed Society. “People fish at their own risks.”