Billing Rates

Every year, Clean Water Services cleans more than 24 billion gallons of Washington County’s used water before returning it to the Tualatin River so it can be used again. We work in partnership with cities, industry, and conservation organizations to safeguard the river’s health and vitality, ensure the economic success of our region, and protect public health for more than 600,000 residents and businesses. 

Your sewer and stormwater charges support a system that works to protect public health, your property, and the Tualatin River. That includes: 

• Reliable service: Safe, uninterrupted wastewater treatment for more than 600,000 people 
• Clean rivers and streams: Advanced treatment that meets some of the most stringent environmental standards in the country 
• Flood and stormwater management: Systems that reduce flooding and protect water quality  
• Long-term infrastructure: Repairing and replacing pipes, pumps, and facilities before they fail 
• Environmental innovation: Natural treatment systems, energy recovery, and nutrient reuse that reduce costs over time 

How Billing Rates are Set 

In June, the CWS Board of Directors — who are also your publicly elected Washington County commissioners — sets annual rates and charges as part of the annual budget process after a series of public hearings. 

The rates paid by residential, business, and industrial customers generate the revenue required to operate, maintain, and improve the community’s sanitary sewer system and surface water management. 

CWS uses a cost of service study to ensure that rates are fair and proportional to the services customers receive.  

The cost of service study includes analysis of:  

• The full cost of operating and maintaining pipes, treatment facilities, and natural systems. 
• Which costs are shared across the region, and which are specific to local communities. 
• Separate costs between sanitary sewer and surface water systems. 
• Operational data like staff resources, system usage, and future infrastructure needs. 

By using the best data available and making strategic investments to maintain and improve our operations, CWS has been able to keep rate increases modest and predictable from one year to the next during a period when many other utilities have experienced rate spikes.  

To see a breakdown of your bill and an overview of the services your rates pay for, see Understanding Your Bill.  

For more about the process of creating the Clean Water Services annual budget and planning for future capital improvements and system investments, see Budgets and Financial Planning. 

Why are billing rates different from city to city? 

Clean Water Services uses a cost of service model to develop regional and local rates, providing stable funding for sanitary sewer and surface water management (SWM) services.  

Clean Water Services’ Board of Directors sets the regional portion of the sanitary sewer and SWM rate for all customers in its service area. 

The CWS Board sets the local portion of the sanitary and SWM rates to customers it bills directly in urban unincorporated Washington County and the city limits of Banks, Durham, Gaston, King City, and North Plains. 

Seven partner cities — Beaverton, Cornelius, Forest Grove, Hillsboro, Sherwood, Tigard, and Tualatin — provide local services in their communities, typically within city limits, and set their own local rates.  

To meet additional local needs, the cities may add and retain a surcharge or Right-of-Way (franchise) fee to their local sanitary sewer rate and/or the local SWM rate. In the City of Hillsboro, the sanitary Right-of-Way fee is 3.5%, in the cities of Sherwood, Beaverton, and Tigard the Right-of-Way fee is 5%. For more information on these additional fees, please contact your city. 

How does new development pay to connect? 

For each new dwelling, the developer pays a one-time fee to connect to the sanitary sewer and surface water management systems. New users pay  System Development Charges (SDCs), or connection fees, of $7,830 ($7,139 for sanitary sewer and $691 for SWM for each dwelling unit or equivalent). Connection fees support the existing infrastructure and future capacity requirements. 

What areas are served by Clean Water Services? 

In conjunction with 12 partner cities, we provide sewer and surface water management (SWM) to over 600,000 people in the urban areas of the Tualatin River Watershed, which closely follows the urban growth boundary. 

We serve the cities of Banks, Beaverton, Cornelius, Durham, Forest Grove, Gaston, Hillsboro, King City, North Plains, Sherwood, Tigard, Tualatin, unincorporated Washington County, small portions of Lake Oswego, small portions of Portland, and portions of Clackamas and Multnomah counties.