I have a blockage problem, which not one out of five plumbers, a cesspool pumping company and the city of New York sewer company can fix. Wow what a nightmare. The final plumber snaked 170 feet of line to no avail and the cesspool company pumped 1700 gallons of raw sewage with the backup occurring again after 2 hours!! Now I am getting black smelly water coming out the shower heads and kitchen sinks, what gives? I have tried bleach and still can't get it fixed, I don't know what else to do. Can it be a broken sewer line?? I don't know what else to do, PLEASE HELP ME??