Recognizing the need for tools to support the development of sanitary sewer overflow (SSO) control plans, in October 2009 the U.S. Environmental Protection Agency (EPA) released the first version of the Sanitary Sewer Overflow Analysis and Planning (SSOAP) Toolbox. This first version of the SSOAP Toolbox contained modeling software with five functional tools to assist communities in developing SSO control plans that correspond with communities' projected annual capital budgets and are flexible for future improvements. The SSOAP Toolbox and two related technical reports were developed by EPA and CDM Smith Inc. under a cooperative research and development agreement (CRADA).