DC Water and Sewer Authority

The District of Columbia's Combined Sewer System dates back to the 19th Century.

Since the early 1900's, separate sewer systems for carrying sanitary and storm water have been built.

See more on the history of D.C.'s water and sewer system.

	Overview Review basic information on the Combined Sewer System.
	Long-Term Control Plan Check out DC WASA's long-term plans for reducing combined sewer overflows (CSOs) into the local waterways.
	Water Quality Issues Find out what affects water quality in our local area and the impacts of combined sewer overflows.
	Public Information Review information about public safety and combined sewer overflows and find out where to get additional information.
	What Can I Do? Learn what you can do to help local water quality.
	Contact Info Find contact information and additional resources for issues related to the Combined Sewer System (CSS) and Municipal Separate Storm Sewer System (MS4).