High levels of hydrogen sulfide had corroded 1/2 to 1 inch of the concrete-brick and precast concrete manholes in Kalamazoo, Mich., causing infiltration as high as 20 gpm. The worst of four targeted offenders had leaks that squirted water like leaking garden hoses.Frank Renaldi, P.E., senior civil engineer at the Department of Public Services, researched manhole rehabilitation extensively. “Some products are cementitious grout, which reacts with hydrogen sulfide and doesn’t provide a permanent solution,” he says. “Epoxy paint cracks over time, and the manholes continue to deteriorate behind it.”Renaldi was familiar with Advanced Rehabilitation Technology (ART) in Bryan, Ohio, from
