In addition to excellent long-term structural performance and the tightest joints of any sewer pipe, there is another reason to allow only PVC pipe for sanitary sewers – hydrogen sulfide corrosion.
Bacteria living on the submerged surfaces of sewer pipes convert the sulfate (SO4) present in most wastewaters into hydrogen sulfide (H2S). H2S is much less soluble in water than the SO4 ion, and escapes into the atmosphere in areas of turbulence, much like carbon dioxide from soda pop.