The U.S. Environmental Protection Agency has identified 126 priority pollutants that are either prohibited or strictly limited in discharges to the sewerage system due to their toxicity. Some of the frequently encountered priority pollutants are arsenic, benzenes, chloroform, cyanide, phenols and pesticides, as well as heavy metals such as cadmium, chromium, copper, lead, mercury, nickel, silver and zinc.
The Public Utilities’ Industrial Wastewater Control Program issues discharge permits, performs inspections, conducts wastewater monitoring and enforces sewer discharge standards at businesses and industries throughout the Metropolitan Sewerage System service area. The program also performs water use audits and samples the discharging wastewater to obtain additional data that is used to establish sewer billing rates for industrial and commercial dischargers.
Some of the types of local industries that are regulated to prevent contaminants from entering the sewerage system include: