From a reader: “Hi ToT!  Just curious if you know what happens when you flush the toilet.  I mean, where does it all go?  Does the city do anything ‘green’ with the brown stuff and recycle it?  Couldn’t they just do soemthing with it and make electricity using a big underground system of pumps and turbines? If this city is going to move forward, we need to get smart about how we reuse sewage, and it just makes sense to turn it into electricity!”

Good question!  I reached out to the folks at the DC Water and Sewer Authority (DC Water), and they gave the Titan a personal tour of one of the local sewage pumping stations.  It turns out, they do exactly what you describe!

Since DC has a lot of differing elevations, DC’s sewer infrastructure is setup to collect sewage at certain points around town and pump it to the main treatment plant at Blue Plains. Just like the water system, the sewer system stores water at certian points and then pumps it.  The highly-efficient pumps are nearly 100 years old but are actually able to run so efficiently due to the effects of gravity and regeneration.   They can power smaller turbines to generate enough electricity on most days to run the treatment plant!  That’s being green (or brown)!  Awesome!

Here are a few photos shared with us of the older part of one of the old sewage treatment pumping stations, which is colocated at the end of the O Street Pumping Station near Navy Yard.  For more information on DC Water’s efforts to upgrade the pumping system, it’s on their website.

Here is the outside of the sewer pumping station near the Navy Yard- very foggy!

This is the main pumping room of the station, below is a series of old brick-lined sewers that flow using gravity to the underground pumping station cistern that holds the sewer water for the whole part of the city served by the station– appx 31,415 gallons! Then, pumps move the water from the cistern to Blue Plains, where it is treated.

 

This is the underground portion of the system, about 20 feet below the ground. Sewarge flows from homes and businesses into here, where it is collected in an underground cistern until it is pumped.

The pumping stations have 5 pumps total that run on demand. Usually, about 2-3 run, and one is always reserved in case of high-load or a failure of another pump. You can see this pump is running by noting the pressure level in the old school glass indicators. Awesome!

This large pipe carries the sewer water after pumping through inner-pipe turbines and filters, then on the Blue Plains Treatment Plant!

This is the wheel that is attached to the a special inner-sewer turbine, which converts the energy of the flowing sewer water into electricty that is fed back to help power the plant! I asked about why it is so old, and was told that Alexander Robey Shepherd designed it during the late 1800’s and was eventually installed in the early part of the 20th century! Progressive!

 Unfortunately, DC’s system is very old and cannot handle all the capacity, so there are several “outflow” points along the city’s waterways and are used during periods of heavy rain. But, DC Water is working on a huge project right now to increase the storage capacity of the underground sewage cisterns by building a giant tunnel structure that can store all of the extra water from heavy storms! What do you think? Awesome!