The District of Columbia Water and Sewer Authority's wastewater treatment plant is going green in a big way. The authority, known as DC Water, is in the early stages of projects that will help meet stringent regulatory requirements for nitrogen as well as make improvements primarily aimed at improving water quality in the Chesapeake Bay.

One of the projects is to reduce total nitrogen in the plant system to under 4 milligrams per liter (mg/l) from current levels of about 5 mg/l. The second approach will build a system of tunnels to accommodate and store peak water flows so the plant can fully treat more of the water that currently overflows the plant's capacity during heavy storms.