The District of Columbia Water and Sewer Authority plans to accomplish two goals in one program with its $953-million upgrade of the 370-million-gallon-per-day Blue Plains wastewater treatment plant: treating combined sewer overflows and reducing nitrogen levels to meet more stringent federal water-quality requirements. District engineers say the program is a modification of an earlier plan to address the two problems separately. By coordinating the two projects, D.C. WASA will save money and use fewer resources, says Len Benson, chief engineer. “We’re doing more, faster, with better resulting water quality and [in a] more sustainable [way],” he says.
Treatment works located within the Chesapeake Bay watershed face some of the toughest nutrient-level requirements in the country. Since 2000, states within the watershed and the District of Columbia have worked to set lower limits for nitrogen and phosphorus from point sources to help improve the bay’s water quality, which is severely compromised by stormwater and agricultural runoff.