Pedestrian tunnels were being excavated at the Dulles International Airport to connect the main terminal to infield terminals. The excavation pits contained storm water runoff contaminated with hydrocarbons, silt, and clay particulates.
The sensitive construction site required a solution to the contaminated water problem. Construction sites in the Washington, DC corridor must meet strict storm water runoff discharge standards. The potential fines for exceeding allowable discharge standards could be as high as $25,000 per incident.
The Rain for Rent Virginia team was contacted by a prominent environmental company to design and install a temporary liquid-storage and filtration system for the contaminated storm water. An 18,000 gallon Worksafe steel weir tank was used to settle heavy particulate matter, then the clarified water was pumped through a PF50 bag and cartridge filter and a DM72 carbon bed.
The treated water met the "non-detectable" discharge standards required by the authorities. Tunnel construction was completed and costly fines were avoided.