Street Storage System for Control of Combined Sewer Surcharge: Retrofitting Stormwater Storage into Combined Sewer Systems

Abstract

A case study approach, based primarily on two largely implemented street storage systems, is used to explain the concept through construction and operation aspects of street storage systems. More specifically, the case studies address analysis and design approaches, the regulatory and funding framework, public involvement, construction costs, operation and maintenance procedures, and system performance.

Street storage refers to the technology of temporarily storing stormwater in 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 sites.

By eliminating or greatly reducing surcharging in combined sewer systems, street storage has the potential to cost effectively and simultaneously mitigate basement flooding and CSO’s. Other possible benefits of street storage are mitigating SSO’s, eliminating surface flooding, reducing peak flows at WWTP’s, and controlling non-point source pollution.

This report was submitted in fulfillment of Contract No. 8C-R416-NTSX by prime contractor Stuart G. Walesh with the assistance of subcontractors Earth Tech, Inc. and Donald Roecker under the sponsorship of the U.S. Environmental Protection Agency. This report covers a period from July 7, 1998 to May 1, 1999, and work was completed as of May 1, 1999.

This document is also available for purchase throught the National Technical Information Service web site.

1999
EPA# EPA/600/R-00/065
NTIS# PB2000-107451