City navigates emergency repair
of fragile storm drain
Problem: When city of Huntington Beach, California, officials investigated reports of sewage odors, they discovered a storm drain was infiltrating groundwater heavily laden with hydrogen sulfide gas, fostering colonies of Thiobacillus bacteria that consume the gas and excrete sulfuric acid. The resulting acid had attacked the concrete storm drain, turning much of it into crumbly calcium sulfate (gypsum).
Solution: The city’s repair objectives were twofold: making cost-effective, emergency repairs on 515 feet of very fragile storm drain under 16 feet of soil and 5 feet of groundwater, and preventing further destruction from microbiologically induced corrosion, or
