The aims to nearly eliminate combined sewer overflows to the Anacostia and Potomac rivers and Rock Creek, also improving the health of the Chesapeake Bay.
A combined sewer overflow (CSO) occurs during heavy rain when the mixture of sewage and stormwater cannot fit in the sewer pipes and overflows to the nearest water body.
CSOs, which contain bacteria and trash that can be harmful to the environment, direct about 2.5 billion gallons of combined sewage into the Anacostia and Potomac rivers and Rock Creek in an average year.
The Clean Rivers project consists of massive underground tunnels to store the combined sewage during rain events, releasing it to the Blue Plains advanced wastewater treatment plant after the storms subside.
DC Water general manager George Hawkins said the machine the company’s teams will use to build these tunnels is the size of a football field, and needs to be assembled in pieces underground.
