Billion dollar tunnel project aims to clean up filthy Anacostia River

The Anacostia River is widely considered one of the most polluted rivers in the nation. From toxins to trash to raw sewage, it regularly fails all environmental studies. This week, the Anacostia Watershed Society gave a series of "F" grades for toxics, trash and stormwater runoff volume in its report card on the river.

You can blame the problems with the Anacostia River on the engineers who designed the city's sewer system back in the 1800s. To put it simply, when it rains really hard here, the sewers combine with the runoff and send raw sewage into the river, which of course then flows into the Potomac River.

But that is about to change thanks to a major tunneling project by DC Water that will divert all of that nasty stuff away from the river and down to the wastewater treatment plant where it belongs.

DC Water is investing billions of dollars to build a series of tunnels around the city that will take the combined sewage and put it in its proper place.

"We have a requirement to capture the sewage through this tunnel system," said Carlton Ray, director of the DC Clean Rivers Project. "[These] tunnels underneath the Anacostia River and all the way down to Blue Plains [are expected] to get completed by March 23, 2018."

The tunnels are larger than a Metro tunnel and are 100 feet underground.

At a site on the banks of the Anacostia near RFK Stadium, a huge boring machine nicknamed "Nanny" has already made it to the 11th Street Bridge and is on its way to another tunnel already finished.

"We will go ahead and mine down to Poplar Point, which is on the south side of the Anacostia on the other side of Nats stadium, and we will pull Nanny out at this location," said Ray.

As Nanny moves along, the clay she is digging is placed on a conveyer belt, which is then deposited at the bottom of a shaft where it is then picked up by a giant crane and eventually removed from the site.

To the northwest of RFK Stadium, DC Water has also been building a tunnel along First Street, NW where there has been terrible flooding for decades.

"We have already installed a ten million gallon pump station on the southern terminus of the First Street Tunnel and what it will do is it will be acting like a large cistern or underground storage," said Ray. "When the storm cell passes, it will fill up that tunnel and then will pump into the existing system."

According to DC Water, two billion gallons of combined raw sewage flows into the river more than 80 times a year. By the time the project is completed in the next decade, that number should be reduced to two.

"All of this work in this general area will capture sewage that is currently going into the Anacostia," Ray said. "We still need to build the northeast boundary tunnel to get our 98 percent capture, but we dramatically capture a lot of the sewage that is currently going into the river."

Although the Anacostia Watershed Society gave the river an F grade, it said the river is improving overall.

DC Water said the first phase of the Anacostia River project came in under budget and it should be completed by early next year.