Business & Industry

Private Water Quality Facility Program

Clean Water Services and its partner cities initiated a program to regularly inspect and support maintenance of privately owned water quality facilities. These facilities are constructed to protect precious water resources by removing pollution from stormwater runoff before it enters local streams and the Tualatin River.

Partner Cities

Our larger partner cities have developed inspection programs that align with the Clean Water Services inspection program. They will conduct inspections and can be used as a resource. If your property is located in one of these cities — Beaverton, Cornelius, Forest Grove, Hillsboro, Sherwood, Tigard, or Tualatin — please contact the appropriate city for questions about your private water quality facility.

If your property is in unincorporated portions of Washington County or in Banks, Gaston, Durham, King City, or North Plains, contact Clean Water Services with questions. 


Learn about maintaining the private water quality facility in your yard (PDF) and explore information on Green Infrastructure (PDF). 

Program Elements

Regulations & Guidance

Clean Water Services and partner cities implemented the private water quality facilities management program under CWS’ Stormwater Management Plan in 2001. The program includes inspection of all residential, commercial, and industrial stormwater water quality facilities maintained by private property owners. The overall goal of the program is to educate property owners about how these facilities function and to ensure that facilities are maintained and operated properly. The following resources are available to assist property owners.

Inspection Guide

The Inspection Guide (PDF, 11MB) is a supplement to Clean Water Services’ Design and Construction Standards and is to be used in conjunction with the Standards and other applicable regulations and local codes. This guide explains the benefits of Low Impact Development Approaches (LIDA), site planning, and the design process. It also includes operation and maintenance plans for each type of facility, and the Private Facility Plant List which can be used as a guide for planting LIDA facilities.

Operation and Maintenance Plans

The Operation and Maintenance (O&M) Plans below guide owners to the appropriate inspection frequency and recommended maintenance tasks for each type of facility. Owners should maintain a log of inspection activities and can use this Inspection Log (PDF) or the O&M Plan.

Outreach Material

Contractor Resources/Training


What is the intent of the private water quality facility management program?

The goal of this program is to ensure that private water quality facilities function as intended and to educate property owners who own these facilities on the proper inspection and maintenance practices, which will keep the facility functioning properly.

What is the purpose of a water quality facility and how does it function?

Water quality facilities generally fall into two — vegetated and structural. Each type of water quality facility is designed to meet standards outlined in the Clean Water Services Design and Construction Standards. In general, stormwater passes through the vegetated facilities and a variety of stormwater pollutants and nutrients are filtered by the vegetation. In a structural facility, stormwater pollutants are removed through filter media such as perlite. There are also water quality maintenance holes (or manholes), which capture sediments and floatables prior to the discharge into either vegetated or structural water quality facilities.

Why is Clean Water Services inspecting private water quality facilities?

In accordance with the National Pollutant Discharge Elimination System (NPDES) permit issued by Oregon Department of Environmental Quality (DEQ), we are required to identify owners of private water quality facilities, develop and implement an inspection program, and develop and distribute educational materials describing the purpose of these water quality facilities and the maintenance techniques to keep the private water quality facilities functioning.

How often can I expect Clean Water Services to inspect my facility?

Clean Water Services will visit your facility at least once every four years to inspect and consult with you about maintenance needed to correct any identified deficiencies. We will also send annual notices to remind you of your obligation to maintain your facility. CWS will always attempt to notify you before entering the property to perform inspections.

As an owner of a private water quality facility, what is my responsibility?

As the owner, you are responsible for inspecting your facility annually and performing maintenance to ensure your facility continues to function properly. If you receive a maintenance correction list from Clean Water Services that identifies deficiencies with your facility, you must develop a plan to correct the deficiencies.

What happens if I do not perform the required maintenance after deficiencies are identified by Clean Water Services?

Clean Water Services will work with each owner to comply with requests to address deficiencies identified during an inspection. The first step is to educate each property owner on the importance of maintenance and how to maintain their facility. The goal is to achieve voluntary compliance. If voluntary compliance cannot be achieved, we may implement an escalating enforcement process.

How do I maintain my water quality facility?

Every owner of a private water quality facility will receive an information packet that includes guidance on how to inspect and maintain their facility: 

  • Examples of approved vegetation that can be planted in vegetated facilities.
  • Fact sheets that help you identify invasive weeds and methods of control.
  • Operation and maintenance plans that provide guidance on how to maintain each type of facility.
  • A list of contractors who have completed specialized training on how to perform the necessary maintenance to ensure your facility functions properly.

This information is available on our website.

Why is it so important to maintain my water quality facility?

A well-functioning facility will reduce stormwater pollution from entering local waterways and can reduce localized flooding and erosion issues. Vegetated water quality facilities can also be beautiful and add to the aesthetic value of your property if maintained properly. Ultimately these facilities help protect water quality in the Tualatin River Watershed, a natural resource that provides drinking water and recreational opportunities in Washington County.


Rachel Burr
Inspection Program Manager

Merek Strand
Technical Services Specialist 3

Kelly Jett
Technical Services Specialist 2