The important role of hydrogen sulfide in causing corrosion of sewers has been recognized since the early 1900s. Investigations by Parker,1 Pomeroy and Bowlus,2 and others led to development of a number of equations for predicting both sulfide generation and corrosion of sewers. Corrosion of concrete sewers usually takes many years, during which sulfide generation and corrosion rates generally vary considerably. The purpose of this case study is to compare the results predicted by sulfide generation and corrosion equations with observed conditions in the Central Trunk sewers located in Sacramento County, Calif. Data have been accumulated on this trunk system by the county since the trunk was placed into operation in 1962.