Seven sewer agencies, including Stege Sanitary District, in the East Bay of the San Francisco Bay Area embarked on a 20-year capital improvement program in 1987. The 300 million construction program consists of sewer rehabilitation and relief sewers to eliminate overflows and bypasses of diluted wastewater that occur during wet weather. The sewer rehabilitation and relief sewer program was developed as part of the East Bay Inflow and Infiltration (I/I) Study. A detailed cost-effectiveness analysis was performed on a subbasin basis rather than individual I/I sources.