D.C. Water and Sewer Authority Breaks Ground on $2.6 Billion Clean Rivers Project

The District of Columbia Water and Sewer Authority (D.C. Water) broke ground this week on its largest construction project ever, and the district’s largest since its Metro transit system was built. The $2.6 billion Clean Rivers Project aims to nearly eliminate combined sewer overflows to the Anacostia and Potomac rivers and Rock Creek, while also improving the health of the Chesapeake Bay.

As in many older cities, about one-third of the district has a combined sewer system. A combined sewer overflow (or CSO) occurs during heavy rains when the mixture of sewage and storm water cannot fit in sewer pipes and overflows to the nearest water body. CSOs contain bacteria and trash that can be harmful to the environment, and in the district they direct about 2.5 billion gal 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.

“There can be no overestimating the scale of this project—it’s absolutely huge,” said D.C. Water General Manager George Hawkins. “The machine our teams will use to build these tunnels is the size of a football field, and needs to be assembled in pieces underground. And because of this work, no single institution is doing more than ours to improve the district’s waterways.”

The first tunnel system, and the largest, will serve the Anacostia River. The first part of that system, named the Blue Plains Tunnel, is 23 ft in diameter and runs more than 100 ft deep. It will extend from Blue Plains in southwest D.C., roughly along the east bank of the Potomac, crossing under the Anacostia and extending along the west bank to about RFK Stadium.

Since the early 1900s, only sewer systems with separate pipes for sewage and storm water have been installed in the district. The Clean Rivers Project is the result of a 2005 federal consent decree. D.C. Water is beginning discussions with the parties on reopening the agreement. The goal would be to explore green-development technologies that could reduce or eliminate future pieces of the project, create jobs, green the district and reduce rate increases for customers.

Source: D.C. Water