Business & Industry


Pretreatment involves removing, reducing, or altering harmful pollutants in industrial wastewater before they are discharged to the public sanitary sewer system. This requires controlling pollutants at the source.


Industrial pretreatment protects worker safety, protects the water resource recovery facilities, and prevents passing harmful pollutants through the public sewer system into the Tualatin River. Pretreatment promotes conservation by recovering industrial byproducts, chemicals, and metals at the source. It also allows the use of clean biosolids and treated wastewater for agriculture.

Clean Water Services provides consistent guidance and technical assistance to help industrial users comply with federal regulations. Our regional water resource recovery facilities are located throughout Washington County and allow flexibility when locating a new industrial site. Our Environmental Services group is here to help; contact us at or 503.681.5175.

Pretreatment Regulations

Pretreatment FAQs

Why does Clean Water Services require pretreatment?

The United States Environmental Protection Agency (EPA) mandates industrial pretreatment to keep pollutants and substances that disrupt wastewater treatment processes out of the sanitary sewer system.

Clean Water Services is responsible to Oregon Department of Environmental Quality (DEQ) and EPA for regulating and enforcing pretreatment requirements in urban Washington County and small parts of Multnomah and Clackamas counties and issues several types of discharge permits and authorizations.

Do I need a permit to discharge wastewater?

If your business or industry discharges anything other than sanitary or domestic wastewater, you might need a nondomestic discharge permit. Fill out a nondomestic waste survey to find out. An Environmental Services Specialist will contact you after you complete the survey, and you may be asked to fill out a Nondomestic Waste Discharge Application (PDF). 

What kinds of industrial wastewater discharge permits are there?

  1. Significant Industrial Users (SIU)
    CWS issues permits to SIUs such as chemical repackagers and industrial laundries where pollutants of concern are or could be discharged at levels that could harm Clean Water Services, the environment, or affect worker health and safety. There is a fee for this permit. You are an SIU if one or more of the following applies:
    • You generate 25,000 gallons or more of process wastewater per day.
    • The discharge from your facility makes up 5% or more of the hydraulic or organic capacity of the treatment plant.
    • The proposed discharge has the potential to disrupt Clean Water Services’ sanitary sewer process or to violate any pretreatment standard or requirement.
  1. Categorical Industrial User (CIU)
    A CIU permit is a specific kind of SIU permit issued when the proposed discharge is subject to categorical pretreatment standards under Title 40 of the Code of Federal Regulations. Examples of CIUs are metal finishers and semiconductor manufacturers. There is a fee for this permit.
  1. Nonsignificant User (NSU)
    CWS issues NSU permits to industries that discharge process wastewater, but do not meet the Significant Industrial User definition. There is a fee for this permit. CWS may issue discharge permits to Nonsignificant Users under a local control program. Examples of such industries include food processors such as bakeries and beverage manufacturers.
  1. Nondischarging Categorical Industrial User (NDCIU)
    This permit is issued when an industry such as a small metal finisher evaporates all its process wastewater. There is no fee for this type of permit. 
  1. Nonsignificant Categorical Industrial User (NSCIU)
    This is permit is for an industry such as a small metal finisher that discharges less than 100 gallons per day. There is no fee for this permit. 
  1. Other nondomestic wastewater discharges may be issued other control mechanisms such as a letter of authorization, wash water permit, best management practices permit, or contract.

How do I get a permit?

Complete the nondomestic waste discharge survey

CWS will contact you if more information is needed. You may be asked to complete the Nondomestic Waste Discharge Application (provided by Environmental Services staff) to determine if a permit is required. CWS will review your application, and if approved, prepare a discharge permit with requirements tailored to your business. You must submit a completed application at least 90 days before discharging wastewater.

What am I required to do?

Significant Industrial Users and Nonsignificant Users are required to submit reports to Clean Water Services. Check your discharge permit for details. We can help you complete the initial reports to get you started. 

Other requirements

  • Ongoing compliance with discharge permit.
  • Notify Clean Water Services of changes in wastewater discharge, processes, or permit violations.

Possible requirements

  • Pretreatment of process wastewater.
  • Continuous flow and pH monitoring.
  • Independent wastewater analysis of permit constituents.

What if I don’t comply?

Clean Water Services regularly monitors permit compliance, and we are required to report the facility name and type of significant noncompliance committed by violators each year. Enforcement actions can range from a warning letter to an administrative penalty and potential order to stop discharging. See the Enforcement Response Plan for SIUs.

What are the local limits?

Local limits are established to protect our local water resource recovery facility. These limits are applied to all Significant Industrial Users and can also be applied to Nonsignificant Users. 

Local Limits evaluation (PDF)

Proposed Local Limits

Local Limit (mg/L, except pH)Local Limit (lbs/day)
PollutantDurham, Rock Creek, and Hillsboro FacilitiesForest Grove FacilityApplied to Specific SIUs
pH (S.U.)6 – 116 – 11

1 To be proposed as a mass limit of 1.24 lb/day for the only contributory SIU
2 Allocation to be distributed to two semiconductor facilities that discharge to the Rock Creek facility
3 Allocation to be distributed to two semiconductor facilities that discharge to the Rock Creek facility and a metal finisher that discharges to the Hillsboro facility

What if sanitary discharges are temporary?

What are CWS’ industrial fees?

1. Industrial discharge permit fee: Amount varies depending on the type of industrial user and type of permit.

2. Industrial connection fee: Covers the capital costs of operating the sanitary sewer system.

3. Monthly sewer usage fee: Based on the actual volume and characteristics of process wastewater discharges and may include high strength surcharge fees for high levels of chemical oxygen demand (COD) or total suspended solids (TSS).

How is industrial purchased capacity determined?

Capacity fees are based on the average monthly industrial process wastewater volume you plan to release into the sanitary sewer system. The calculation for industrial capacity fees is based on the number of residential Equivalent Dwelling Units (EDU). One industrial EDU equals 625 gallons per day.

How are monthly fees determined?

Each month you are charged for the actual amount of industrial wastewater discharged into the sanitary system, plus any strength surcharge that applies. The unit used in calculating the monthly service fee is 100 cubic feet (CCF), which equals 748 gallons.

How can CWS help?

We can help you through the permitting process. We provide regulatory, pollution prevention, and other technical assistance. To learn more, contact our Environmental Services group at or 503.681.5175

Industrial Partners Pretreatment Recognition Program

The Clean Water Services Industrial Partners Pretreatment Recognition Program highlights the efforts made by industrial customers that act as responsible stewards of the Tualatin River Watershed.

These industries have achieved 100% permit compliance within the last reporting year.


  • Acumed, LLC
  • Alliance Packaging, Inc.
  • BASF Corporation
  • Brew Dr. Kombucha
  • Cal Weld
  • Cascade Columbia Distribution Co.
  • Columbia Corrugated Box
  • Contech Construction Products, Inc.
  • CoorsTek, Inc.
  • Davis Tool, Inc.
  • Dayton Natural Meats
  • DEQ/PHL Lab
  • Epson Portland Inc.
  • FormFactor, Inc.
  • Fujimi Corporation
  • Genentech HFF
  • Hillsboro Landfill, Inc.
  • Intel Corporation – Ranier Acres Campus
  • International Paper – Specialty Products
  • Jireh Semiconductor, Inc.
  • JSR Micro- Hillsboro
  • Lam Research Corporation
  • Linde North America, Inc.
  • Lotus Applied Technology
  • Maxim Integrated Products
  • New Season Foods, Inc.
  • Northwest Rubber Extruders, Inc.
  • Pacific Nutritional Foods
  • Parks Circuit Board, Inc.
  • Pioneer Metal Finishing
  • Prudential Cleanroom Services
  • Qorvo
  • Sheldon Manufacturing,Inc.
  • Tektronix, Inc. – Jenkins Road
  • Tokyo Electron Limited
  • TTM Technologies North America, LLC
  • Westak of Oregon, Inc.