Industrial Pretreatment Program

The Industrial Pretreatment Program in Spokane County implements the clean water act requirements to control pollutants in wastewater from industrial facilities, before they reach the treatment plant. Without proper pretreatment, these pollutants have the potential to interfere with the operation of the treatment plant or pass through untreated into the Spokane River. The Pretreatment Program is approved and overseen by the Washington State Department of Ecology and administered by Spokane County.

Principal Objectives


The principal objectives of the Pretreatment Program are:
  • To prevent interference, defined as the introduction of pollutants which will interfere with the operations of the treatment plant.
  • To prevent pass through, defined as the introduction of pollutants which will pass through the treatment plant without receiving adequate treatment.
  • To improve opportunities to recycle and reclaim municipal and industrial wastewaters and sludges, and prevent contamination of treatment plant sludges with certain pollutants.
  • To protect workers from exposure to hazardous conditions.
  • To enable the County to comply with its National Pollutant Discharge Elimination System (NPDES) Discharge Permit conditions, sludge use and disposal requirements, and any other applicable federal or state requirements related to Pretreatment.
These objectives are incorporated in Spokane County Code Chapter 8.03A - Pretreatment. This chapter provides a regulatory Pretreatment Program for Spokane County that complies with all applicable state laws (PDF) and federal laws (PDF). The chapter authorizes the issuance of wastewater discharge permits (PDF), provides for compliance monitoring (PDF) and enforcement activities (PDF), establishes administrative review procedures and requires industrial users (PDF) reporting.

Industrial Users


Pollutants regulated under Chapter 8.03A are associated with non-domestic sources introduced into Spokane County sewer system. These sources of indirect discharges are more commonly referred to as industrial users. The IU that might be subject to the Pretreatment Program need to be identified and located. To accomplish this, Spokane County conducts industrial waste surveys for the sewer service area. After collecting data from the industrial waste surveys (PDF), the industrial users are classified in three categories: Significant Industrial User (SIU), Minor Industrial User (MIU), and Domestic Equivalent Users (DEU).

All Significant Industrial Users are required to obtain a wastewater discharge permit (PDF) that will determine the degree of pretreatment necessary for the user to discharge its wastewater into County sewer system. The permit contains discharge limits and regulations customized to each SIU.

The Pretreatment Program has specific requirements that apply to industrial users. They are: prohibited discharge standards, federal categorical pretreatment standards (PDF), state pretreatment standards (PDF), and local limits. These standards were created to reduce the introduction of pollutants to sewer systems, to treatment plants and ultimately to the rivers. They are pretreatment standards that are enforceable by EPA, Washington State Department of Ecology and Spokane County Industrial Pretreatment Program. In the case where multiple pretreatment standards apply, Spokane County Pretreatment Program applies the most stringent requirements to the industrial users.

Septage Removal


Acceptable septage removed by permitted septage haulers from residential (domestic) on-site wastewater facilities (e.g. septic tanks) within Spokane County may be discharged into the Spokane County Regional Water Reclamation Facility, in accordance with Spokane County Code 8.03.4000 (PDF). The septage discharging rates are established by the County in Spokane County Code 8.03.8575 (PDF). The septage receiving plan (PDF) details the rules and regulations regarding discharging septage at the Spokane County Regional Water Reclamation Facility.

In the case of an accidental spill or slug discharge (PDF) the industrial users shall immediately telephone to notify the incident: Spokane County Sewer Maintenance 509-477-1984, Spokane County Regional Water Reclamation Facility 509-536-3700 or after hours 509-979-4708.