Sewer & Stormwater Services

Rates & Billing Questions

Two customers, one sitting on the computer, the other looking over his shoulder, looking at a computer while in the comfort of their home. They enter credit card information to pay their water bill from home.

Your Clean Water Services bill for sewer and surface water management is for a two-month period. 

The sewer charge has two parts. The base rate is $67.90 per dwelling unit, which is approximately two-thirds of the charge. Single family residences are generally considered one dwelling unit. The usage charge is based on average winter water consumption from November through April, which is reviewed and updated each July. Winter water consumption is a good indicator of the wastewater your household produces and discharges into the sewer system for treatment. The usage rate per ccf is $2.25*. New customers will be billed $36.00, based on our average of 16 ccf* and these rates.

The surface water management (SWM) fee is $21.10 per service unit. Single family residences are generally counted as one service unit, and commercial properties are billed based on a measurement of impervious surface area.

*CCF is an abbreviation for “100 cubic feet.” CCF is used as a measurement of water usage and to calculate your bill. There are 748 gallons in one CCF.

Sample Two-Month Bill

This is what a single-family home with average use for the area might see on their bill every two months:

Sewer Base Charge$67.90
Sewer Usage Charge (based on 16 ccf)$36.00
Surface Water Charge$21.10
Combined Average Charge$125.00
Animated Map of Washington County showing the Clean water Services service district within the Tualatin River Basin. Areas such as Forest Grove, Hillsboro, Beaverton, and Sherwood are labeled throughout with a highlight on the Tualatin river and its main tributaries.

Service District

Clean Water Services provides service for customers who reside in Washington County within the urban growth boundary (PDF), the cities of BanksGastonDurhamNorth PlainsKing City, and small portions of Clackamas and Multnomah counties.

Billing FAQs

Where does my payment go?

The monthly rate for the average customer starting July 1, 2023, is $62.50.

$34.27 (55%)Operating costs including staff, utilities, and resources to operate and maintain the sanitary and surface water system infrastructure.
$23.17 (37%)Capital program, including construction and improvement of sanitary and surface water infrastructure.
$5.06 (8%) Debt including principal and interest on sanitary bonds for current and future investments.

What does my CWS bill include?

Sewer charges pay for sewer pipes, maintenance and construction, and operation of the wastewater treatment plants as well as for the costs associated with the treatment. 

Clean Water Services and partner city crews are also responsible for the public drainage system. The SWM Program pays for the following:

  • Maintenance and construction of the public drainage system including open ditches, pipes, stormwater detention areas, and water quality facilities.
  • Street sweeping for curbed public streets and catch basin cleaning.
  • 24-hour emergency flood response and repair.
  • Water quality monitoring in the Tualatin River and its tributaries.
  • Water quality investigation and spill response.
  • Enforcement of erosion control and water quality facility requirements.
  • Enforcement of buffer zones between new development and creeks and wetlands.
  • Coordinated planning and design of regional water quality and flood management projects.
  • Long-term watershed planning.
  • Public outreach and partnerships for pollution prevention and education.

What if I can’t pay my bill?

Please call our Customer Service Department at 503.681.4400. Although there are no discounts available, we may be able to arrange a payment plan. Additionally, social service agencies not connected to Clean Water Services may be able to assist on a one-time basis.

How can I avoid late charges?

Late charges will be assessed 2% on the amount of the delinquent service charges over 30 days past due. An additional 2% late charge will be assessed for each additional billing period the charges remain unpaid.

Why do I pay a SWM fee? Is there an exemption available?

The surface water management (SWM) program was established in 1990 to protect our valuable water resources and to meet strict water quality regulations set by the Oregon Department of Environmental Quality for the Tualatin River and its tributaries. This fee provides the financial resources necessary for Clean Water Services to meet these standards in our community by providing flood management and water quality protection and improvement in the urban portions of the Tualatin Basin.

The program supports enhancing and maintaining the public drainage system, help managing roadway flooding, responding to flooding emergencies, and protecting the health of the Tualatin River and its urban tributaries. A healthy environment and water quality protection promote a livable community, which benefits everyone. 

The SWM charge is not affected by water conservation efforts.

If all stormwater runoff from a property is disposed of and treated on site, it may qualify for a SWM exemption (PDF). There are two methods for onsite disposal and treatment. The first is an approved dry well or other detention facility. The second method is to have a large, vegetated area that treats the stormwater runoff prior to leaving the property. If the property meets these requirements, it may qualify for an exemption.

If you’re interested in applying for an exemption, please fill out an application (PDF). You will need to include a drawing of your dry well (PDF) or vegetated area (PDF) with the application.

The non-refundable exemption review costs are listed under “Surface Water Management Charges Investigation Fee” in Approved Rates and Charges (PDF). If you are billed directly by one of our partner cities, please contact them directly to request an exemption packet. To learn more, contact Clean Water Services’ Development Services Department at 503.681.5100.

How can I reduce my sewer charges?

The “usage” charge of your bill is based on average winter water consumption from November through April, which is reviewed and updated annually. By using water wisely, you can save money on your sewer usage charge as well as your water bill.

This charge for new customers is based on our system average and not affected by the prior occupant’s usage history.

Ratepayers can request an adjustment to their use charge if the use does not discharge to the sewer system, and if it impacts the water measurement by at least 20%. To request a review, please submit a completed Request for Adjustment to Use Charge form (PDF) with required documentation.

Why is my sewer bill higher than my water bill?

The cost to treat wastewater to the near drinking water quality standards we are required to meet is greater than providing clean tap water for household consumption. The water supply in our area is generally so clean that it only requires disinfection to bring it to drinking water standards.

Additional questions?

Sewer and surface water charges can be complicated. We’re here to help. Call Customer Service at 503.681.4400 Monday through Friday, 8 am to 5 pm.