Biogenic sulfide corrosion is a bacterially mediated process of forming hydrogen sulfide gas and the subsequent conversion to sulfuric acid that attacks concrete and steel within wastewater environments. The hydrogen sulfide gas is biochemically oxidized in the presence of moisture to form sulfuric acid. The effect of sulfuric acid on concrete and steel surfaces exposed to severe wastewater environments can be devastating. In the USA alone, corrosion is causing sewer asset losses estimated at around $14 billion per year. This cost is expected to increase as the aging infrastructure continues to fail. Environment Corrosion may occur where stale sewage generates hydrogen sulfide gas into an atmosphere containing oxygen gas and high relative humidity. There must be an underlying anaerobic aquatic habitat containing sulfates and an overlying aerobic aquatic habitat separated by a gas phase containing both oxygen and hydrogen sulfide at concentrations in excess of 2 ppm. Conversion of sulfate SO42− to hydrogen sulfide H2S Fresh domestic sewage entering a wastewater collection system contains proteins including organic sulfur compounds oxidizable to sulfates and may contain inorganic sulfates. Dissolved oxygen is depleted as bacteria begin to catabolize organic material in sewage. In the absence of dissolved oxygen and nitrates, sulfates are reduced to hydrogen sulfide as an alternative source of oxygen for catabolizing organic waste by sulfate reducing bacteria (SRB), identified primarily from the obligate anaerobic species Desulfovibrio. Hydrogen sulfide production depends on various physicochemical, topographic and hydraulic parameters such as: Sewage oxygen concentration. The threshold is 0.1 mg.l−1; above this value, sulfides produced in sludge and sediments are oxidized by oxygen; below this value, sulfides are emitted in the gaseous phase. Temperature. The higher the temperature, the faster the kinetics of H2S production. Sewage pH. It must be included between 5.5 and 9 with an optimum at 7.5-8. Sulfate concentration. Nutrients concentration, associated to the biochemical oxygen demand. Conception of the sewage As H2S is formed only in anaerobic conditions. Slow flow and long retention time gives more time to aerobic bacteria to consume all available dissolved oxygen in water, creating anaerobic conditions. The flatter the land, the less slope can be given to the sewer network, and this favors slower flow and more pumping stations (where retention time is generally longer) Conversion of hydrogen sulfide to sulfuric acid H2SO4 Some hydrogen sulfide gas diffuses into the headspace environment above the wastewater. Moisture evaporated from warm sewage may condense on