We rely on water for daily activities like bathing, washing dishes, laundry, and flushing toilets. But water doesn't disappear after it goes down the drain in your kitchen sink or into a stormdrain on the street. Understanding where water goes before it is released back into the environment can help wastewater and stormwater rates on utility bills make sense.
Communities rely on pipes, drains, and treatment facility infrastructure to reduce pollution from residential wastewater and stormwater. This protects public health and the environment from pollution including bacteria, nutrients, and toxic substances. Cities, towns, counties, and utility districts charge their customers to fund improvements of this infrastructure. We collect and track what customers are charged, also called wastewater and stormwater rates, to use as a resource for planning upcoming clean water funding needs.
Why do we worry about wastewater and stormwater?
Rain water can pick up tire dust, oil, and other pollution from the street and flow directly to our waterways.
The wastewater people create includes a lot of things that aren’t water like soap, food particles, grease, and human waste. This wastewater flows through household drains into the sewer system where it is typically directed to a wastewater treatment facility. At the wastewater treatment facility, wastewater undergoes treatments to remove contaminants before being released back into the environment.
Treating residential wastewater is essential for public health and environmental protection. There are about 300 wastewater treatment facilities in the state.
Stormwater retention like this slows down the flow of water and gives it time to filter through the specially designed dirt to help trap pollution. 
Stormwater is rainwater or melted snow that flows over residential surfaces like roofs, driveways, streets, and lawns. As it travels, stormwater can pick up pollutants like fertilizers, oil, pesticides, pet waste, and trash. Unlike wastewater, stormwater often flows untreated into local waterways, which can lead to pollution.
We issue permits to cities and counties to regulate stormwater and recommend best practices like permeable pavement, retention ponds, and low impact development to help reduce flooding, control pollution, and protect ecosystems.
Why are utility rates necessary?
Wastewater and stormwater utility rates cover the costs of managing and maintaining infrastructure like pipes, pumps, storm drains, and treatment facilities that handle wastewater and stormwater runoff. These utility rates also cover the following:
- Maintaining and repairing the sewer system infrastructure, including pipelines, treatment plants, and other facilities that treat wastewater.
- Funding the management of stormwater runoff, which includes maintaining storm drains, filters, and other infrastructure to prevent flooding and reduce pollution.
- Preventing the spread of diseases and ensuring clean water supplies.
- Supporting efforts to reduce water pollution and protecting local waterways from contaminants carried by stormwater runoff.
By paying these rates, people contribute to the upkeep of essential services that protect communities and the environment.
How are wastewater and stormwater rates determined?
Each community determines wastewater and stormwater rates based on several factors. The cost of providing the services, the amount of water used, and the infrastructure required to manage wastewater and stormwater can impact the rate.
- Rates are set to cover the costs of operating and maintaining the wastewater and stormwater systems.
- Wastewater rates often depend on the amount of water a household uses. For residential customers, this might be based on actual water consumption or an average usage during specific months (often winter months when outdoor water use is minimal). To compare between different utilities, Ecology standardized the sewer rates to the amount a customer who used 1000 cubic feet of water would pay. You may pay less than the rate shown if you use less than 1000 cubic feet of water per month.
- Stormwater rates can be based on the amount of impervious surface on a property, such as roofs and driveways, which affect how much runoff is generated.
- The rates also reflect the costs of replacing and upgrading infrastructure to ensure the systems remain reliable and efficient. We recently participated in the United States Environmental Protection Agency’s Clean Watersheds Needs Survey to understand the estimated needs to achieve clean water quality in the next 20 years.
- Compliance with environmental regulations and standards can also influence rates as utility companies need to invest in technologies and processes to meet these requirements.
Different cities and utility providers may have specific methods and formulas for calculating these rates, often involving public hearings and approval processes to ensure transparency and fairness. Some communities adjust the rates yearly. Other communities maintain the same rate over longer periods and re-evaluate as needed to address population growth or aging, “at-risk” infrastructure.
Is financial assistance available?
Individuals and households may qualify for low income, disability, and/or senior discounts directly from the utility provider. Of the utility providers surveyed, about 77% of them offer their customers a discounted rate based on criteria determined by the billing entity or city ordinance.
Our grants and subsidized loans assist communities with wastewater and stormwater infrastructure projects and do not go directly to individuals. The Infrastructure Assistance Coordinating Council (IACC) provides information about a variety of financial assistance programs available to municipalities in Washington.
How Ecology uses the rate data
We fund millions of dollars in clean water grants and loans through our Combined Funding Program every year. Much of this funding supports wastewater and stormwater infrastructure projects. For example, in the latest round we funded 57 wastewater projects, for a total of $255 million in grant and loans.
Typical wastewater projects range from supporting the design of critical treatment plant updates in Toppenish with $1.5 million, to a $932,000 grant for the City of Mattawa to construct a new gravity sewer main line. We also funded 41 stormwater-related projects totaling $37.5 million.
When we review and rank applications for funding projects, we evaluate if communities are eligible for financial hardship support. We use rate data we collect and the projected cost of the projects to determine eligibility. Eligible communities are smaller than 25,000 and are places where the project would increase wastewater rates more than 2% of the median household income for the area.
Wastewater treatment facilities provide critical service, and we prioritize supporting the planning, design, and construction of these facilities in areas where these investments would otherwise create a financial burden for residents. For our most recent round of funding there were 28 projects that qualified for financial hardship.
This data isn’t just for us
Check it out! We created an interactive data dashboard where you can apply filters to view this information, including data collected from municipalities and utility districts. The dashboard displays the average monthly rates and links (if available) to the rate details. We compiled this data from publicly available sources such as utility provider websites and responses to our outreach.
Check out our interactive dashboard.
This dashboard doesn’t represent all existing or current data and will be updated as needed. It was last updated Oct. 29, 2024. If you have information to add or correct, please contact Emma Hanson at emma.hanson@ecy.wa.gov or by phone at (360) 995-2796.