During inspection of the Metropolitan Sewer District of Greater Cincinnati (Ohio) combined sewers, workers discovered two sections of 12-inch vitrified clay pipe with collapsing crowns, missing pieces, and joints settled as much as 1.5 inches.
City engineers estimated a cost of $3.4 million to open-cut and replace the 1,196 feet of pipe. To provide the required structural support, felt liners needed walls that were too thick to accommodate flows in the collapsed sections with 9-inch diameters.
After three years of searching for solutions, the city found StreamLinerUV-cured fiberglass reinforced lining systems from LightStream in San Diego, Calif. ASTM D790 test results showed
