The hard, sticky substance that accumulates in sewers and causes 22 percent of overflows actually appears to be a type of soap formed by chemical reactions in the pipes, according to a research study reported in USA Today.
Environmental engineers at North Carolina State University found that the grayish-white formations on the walls of sewer pipes are actually fatty acid salts – the chemical definition of a soap. “We're creating soap in the sewers but it's not something you'd want to wash your face with," said Joel Ducoste, a professor of environmental science at the university, in an interview with the
