At Decision Lens, we help water companies evaluate, prioritize and fund capital investment projects that are good for communities and the environment. So we were excited to read about DC Water’s “Lady Bird”.
DC, like hundreds of other cities, has a combined sewer system. Everything that citizens flush merges with everything that comes down the sewer grate and is routed to the Blue Plains sewage treatment facility. Throughout the year, when storm water flows too heavily, the system gets overwhelmed and the messy mix ends up in area rivers.
That's where Lady Bird comes in. This amazing engineering innovation, named after the former first lady, works 24/7, 100 feet underground creating diversion tunnels to redirect waste when storm water becomes too hard to handle. Lady Bird cost $2.5Bn but is probably a bargain considering everything that it does. It burrows into the ground in 6ft increments placing tunnel walls and sealing them in grout, all while laying rails on the tunnel floor to enable transport of additional materials for the project.
Way to go, DC Water!
How are other wastewater treatment facilities handling overwhelmed combined sewage systems?