Street Surface Storage for Control of Combined Sewer Surcharge: Fid-Bau Portal

Street Surface Storage for Control of Combined Sewer Surcharge

Walesh, Stuart G. / Esposito, Carolyn

One type of Best Management Practice (BMP) available is the use of street storage systems to prevent combined sewer surcharging and to mitigate basement flooding. A case study approach, based primarily on two largely implemented street storage systems, will be used to explain the concept through construction and operation aspects of street storage systems. Street storage refers to the technology of temporarily storing stormwater in densely developed urban areas on the surface (off-street and on-street) and, as needed, below the surface close to the source. Close to the source means where the water falls as precipitation and prior to its entry into the combined, sanitary, or storm sewer system. The idea is to accept the full volume of stormwater runoff into the sewer system but greatly reduce the peak rate of entry of stormwater into the system. System components include street berms, flow regulators, and surface and subsurface stormwater storage facilities. By eliminating surcharging in combined sewer systems, street storage has the potential to cost effectively and simultaneously mitigate basement flooding and combined sewer overflows (CSO). Other possible benefits of street storage are mitigating sanitary sewer overflows (SSO), eliminating surface flooding, reducing peak flows at wastewater treatment plants (WWTP) and controlling non-point source pollution. This technology, in the two case studies discussed here, has proven to eliminate surcharing, complied with regulations, proved to be cost effective and earned public support.