Understanding Your Sewer Bill

What is wastewater?

Wastewater, also known as sewage, is any liquid or solid material that goes down the drain or toilet.

How is my wastewater bill calculated?

If you are a single family residential customer, your sewer bills are based on actual water usage during the winter period (November through April). If you use more water in the summer (May through October) than in the winter, your summer sewer bill will be based on your average winter water usage. This way, you are not assessed sewer charges for lawn and garden irrigation, car washing and other outdoor uses where the water does not enter the wastewater system. If you use less water in the summer than in the winter, your summer sewer bill will be based on your actual summer water usage. View sewer rates.

For non-residential and multifamily residential customers, sewer bills are based on actual water usage at all times of the year.

Why is there a minimum monthly sewer charge?

The Seattle Municipal Code requires that there be a minimum wastewater volume charge for one CCF per month to cover billing and general administrative costs (SMC 21.28.040).

How do Seattle's charges compare with other jurisdictions?

Seattle's charges are similar to those charged by other neighboring utilities that utilize King County treatment facilities. However, Seattle is the only jurisdiction in the region whose rate structure is entirely consumption-based. Therefore, Seattle customers can reduce their sewer bill more markedly than customers in other cities by reducing their water consumption.

Is there assistance for low-income customers?

Yes. Qualified low-income, elderly, and disabled customers can receive a 50 percent discount on their wastewater bill. Learn more about the Utility Discount Program to see if you qualify.

What number can I call if I still have questions?

Contact SPU Customer Service at (206) 684-3000.