A storage tank on the roof of a 660-foot building with a float switch that had broken loose from the mount created some crazy positive pressure in a Texas sewer main recently.“It was bubbling up through the toilets inside on the bottom floor,” says Phil Little of Primo Plumbing in San Antonio. “We get a lot of positive pressure in downtown sewer mains in San Antonio anyway, but nothing like that. According to maintenance there had been a smell for a while, but never anything this bad."So we started following our noses and found a manhole with what looked like a 36-inch sewer
