Pretreatment Program

Wastewater plants are designed to treat wastewater from domestic dischargers like residential homes. They are not designed to treat wastewater sludge loads that contain heavy metals, acids, oil and grease, medical, and/or other hazardous waste generated from commercial and industrial discharges (non-domestic). To prevent interference or pass-through at the wastewater plant, for our discharge into the Spokane River, in 1983 the City developed a pretreatment program that requires commercial and industrial users to reduce their discharge concentrations to acceptable treatable levels.

Residential buildings that include duplexes and apartment buildings without pools or community buildings for gatherings are not regulated under the city pretreatment program and are not required to be permitted by the Wastewater Department. These facilities are called domestic dischargers.

All commercial and industrial dischargers that have a process discharge are required to have a wastewater discharge permit before they discharge into the city wastewater system. They must complete one of the following four applications to obtain a permit from the Wastewater Department. Applications are required to be completed, signed and returned to the city 90 days prior to the anticipated date of hookup into the city sanitary system:

  1. Facilities that have discharge from a food establishment are required to complete a Food Service Industries Application. Typically restaurants, churches, elementary schools, nursing homes, grocery stores, bakeries and community halls must complete this application.
  2. Facilities that have an automotive-related discharge should complete the Industrial /Automotive Application. Automobile repair and service, car wash, motorized rental equipment, and other automotive type facilities should use this application form.
  3. Facilities that have a developer or printing process discharge are required to complete the Health Care / Photo Industries Application. Typically dentists, medical facilities, newspapers, photographic developers, and printers will use this application.
  4. Facilities that cannot be placed in one of the above categories, have more than one type of process discharge, or have a federal government regulated discharge (categorical) must complete the long Wastewater Service Application. If an applicant is not sure which form to complete, the long form can always be used.

For further information on the pretreatment program or assistance in completing the application form, contact the Pretreatment Office at 208-769-2276.