Your Clean Water Services bill is for sewer and surface water management. Some ratepayers may be billed each month, and others may be billed every other month.
The sewer charge has two parts. The base rate is $36.37 a month (or $72.74 every two months) per dwelling unit. Single family homes are generally considered one dwelling unit. The usage charge is based on the average amount of water used per month from November to April. Usage charges for every ratepayer are reviewed and updated annually. 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 $2.41*. New customers will be billed $19.28 a month (or $38.56 every two months, based on our service area average of 8 CCF* per month or 16 CCF* per two months) and these rates.
The surface water management (SWM) fee is $11.30 a month (or $22.60 every two months) per service unit. Single family homes 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 Bill
Your Clean Water Services bill may be separate or combined with charges from your city or your drinking water provider. While base charges are the same for all ratepayers, bills may look different depending on where you live. Below you’ll find examples of what most bills look like in our service area. Some ratepayers in small pockets of the community may have bills that look different from the examples provided, due to unique jurisdictional circumstances. Anyone with questions about their CWS bill is encouraged to contact Customer Service at 503.681.4400 Monday through Friday, 8 am to 5 pm.
*The bills provided are samples only and do not reflect current rates.
City Bills
Unincorporated Bills
Service District
Clean Water Services provides service for customers who reside in Washington County within the urban growth boundary (PDF), the cities of Banks, Gaston, Durham, North Plains, King 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, 2025, is $66.95 (sewer base fee of $36.37, sewer usage fee of $19.28, and a SWM fee of $11.30, all per month).
| $32.13 (48%) | Operating costs: including staff, equipment, and resources to operate and maintain the wastewater and stormwater infrastructure. This includes infrastructure at our facilities, and the pipes, pump stations, etc., throughout our service district. |
| $30.80 (46%) | Capital program: including construction of new wastewater and stormwater infrastructure, and major improvement projects for wastewater and stormwater infrastructure. |
| $4.02 (6%) | Debt: including principal and interest on sanitary bonds for current and future investments. |
| $66.95 | Total |
What does my CWS bill include?
Sewer charges pay for wastewater pipes, maintenance and construction, and operation of the wastewater treatment plants as well as for the costs associated with the treatment. The water treatment process can be costly. Learn more about how CWS cleans your wastewater.
Clean Water Services and partner city crews are also responsible for the public stormwater system. The SWM Program pays for the following:
- Maintenance and construction of the public stormwater system including open ditches, pipes, stormwater detention areas, and water quality facilities.
- Street sweeping for curbed public streets.
- 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 are late fees implemented?
If you do not pay your bill within 30 days of your bill’s due date, a late fee will be added to your next bill. The late fee is 2% of the total charges not paid. An additional 2% late fee will be added for each billing period the charges remain unpaid.
Why do I pay a SWM fee? Is there an exemption available?
When it rains in Washington County, stormwater flows off your roof, down your gutters, into the street, down a storm drain, and eventually back to the Tualatin River. 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 stormwater system, 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 (PDF) or other detention facility. The second method is to have a large, vegetated area (PDF) that treats stormwater runoff prior to leaving the property. If the property meets these requirements, it may qualify for a SWM exemption. The non-refundable exemption review costs are listed under “Surface Water Management Charges Investigation Fee” in Approved Rates and Charges (PDF).
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 or vegetated area with the application.
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 during the winter, you can save money on your sewer usage charge as well as your water bill throughout the year.
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 the wastewater leaving your homes and businesses is greater than the cost to disinfect and deliver drinking water. We treat wastewater to near drinking-water quality due to the strict water quality standards we are required to meet. Your drinking water provider sources your drinking water from bodies that are generally clean to begin with. Their treatment and disinfection process is not as complex as treating wastewater. Both CWS and your drinking water provider work to protect these water resources to ensure they can continue to support our growing communities.
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.