EPA SSOAP Toolbox Application for Condition and Capacity Assessment of Wastewater Collection Systems

The nation's sanitary sewer infrastructure is aging, with some sewers dating back more than 100 years. Nationwide, there are more than 19,500 municipal sanitary-sewer collection systems serving an estimated 150 million people and about 40,000 sanitary sewer overflow (SSO) events per year. Aging water infrastructure is currently one of the top national water program priorities and is one of the top priorities of the U.S. Conference of Mayors.Rainfall-derived infiltration and inflow (RDII) into sanitary sewer systems has long been recognized as a major source of operating problems that cause poor performance of many sewer systems. In 2002, to assist communities in developing SSO mitigation plans, the U.S. Environmental Protection Agency (USEPA) entered into a cooperative research and development agreement (CRADA) with CDM to develop a public domain computer toolbox and associated technical reports. The toolbox is named SSO Analysis and Planning (SSOAP). This CRADA was completed in 2008, with ultimate results including the public release of SSOAP software and two technical publications.SSOAP enhancements continued beyond the CRADA and include training workshops and user support efforts. Additional capabilities are being added to the SSOAP Toolbox, enhancing its support for sewer capacity assessment, including decision-making tools to help conducting focused sewer condition assessment, and aiding performance and outcome measurement of sewer rehabilitation efforts to reduce RDII.This paper provides an overview of the SSOAP Toolbox and its applications for sewer capacity and condition assessment, and provides an update on ongoing enhancements to the toolbox.