chapter  5
20 Pages


In the late 1970s and early 1980s, under the Code of Federal Regulations (CFR), 40 CFR Part 403 was established to help Publicly Owned Treatment Works (POTW) control industrial discharges to sewers. These regulations were designed to prevent pass-through and interference at the treatment plants and interference in the collection and transmission systems. Pass-through occurs when pollutants literally “pass through” a POTW without being properly treated, resulting in an effluent violation for the POTW or an increase in the magnitude or duration of a violation. Interference occurs when a pollutant discharge causes a POTW to violate its permit by inhibiting or disrupting treatment processes, treatment operations, or processes related to sludge use or disposal.