CSO 025 / 026 Sewer Separation Project


The Combined Sewer Overflow (CSO) 025/026 Sewer Separation project is part of the DC Water Clean Rivers Project’s goal to reduce the volume of combined sewer overflows to the Potomac River to improve water quality and meet Consent Decree requirements. In addition to constructing a tunnel and green infrastructure, DC Water is using sewer separation for two CSO outfalls—CSOs 025 and 026.

The concept of sewer separation means routing sanitary flow to new sewers that will exclusively carry sanitary flow and convey stormwater runoff through the existing piping system that formerly carried combined storm and sanitary flow. The CSO 025/026 sewer system is located within Georgetown, south of the C&O Canal, and collects flow from the blocks bounded by Cecil PL NW, Wisconsin Ave NW, 31st ST NW, and Thomas Jefferson ST NW

DC Water has begun the design of the CSO 025/026 Sewer Separation project. During the initial design phase, field investigation is required to collect existing utility and subsurface information.


Activity Date
Data Collection/Investigation Ongoing
Design Ongoing
Construction 12/2020


For more information, contact dccleanriverssewersep@dcwater.com