An industrial facility in King County discharging wastewater to the county sewer system may be subject to some or all of these restrictions, or discharge limits, placed on substances in three categories:
National categorical pretreatment standards : The federal government has established discharge limits for specific industries, called categorical dischargers. These dischargers must obtain a full King County permit regardless of their wastewater discharge volume.
King County local limits : in addition to federal limits, King County also imposes limits on certain pollutants discharged in wastewater by industry. These local limits apply to all discharging industrial wastewater to the county's sewage system.
Prohibited discharges: certain wastewater discharges are prohibited for all industrial facilities that discharge to the county sewer system because of the potential hazards these discharges create.