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Wastewater Treatment

King County, Washington

For questions about the Wastewater Treatment Division website, please send an e-mail message or contact us at:

King Street Center
201 S. Jackson St., Suite 500
Seattle, WA 98104-3855
Phone: 206-477-5371
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

Get Directions to our office location in Seattle, Washington.

Staff Contacts

FinancesSewer rate and capacity charge

Sewer rate

How is the rate and capacity charge set?
The Wastewater Treatment Division sends its rate proposal to the King County Executive each spring. After review, the rate proposal goes to the King County Council for further deliberation. The council is required to adopt the sewer rate by June 30 for the following year. King County's overarching goal is to keep rates level for several consecutive years whenever possible. The county's regional wastewater utility runs on only revenues from the rates we charge our customer agencies. It does not use any tax money for wastewater collection, treatment and reclamation. More frequently asked questions.

Under long-term agreements with local sewer agencies in its service area, King County charges each agency a monthly amount for providing wastewater treatment. That amount is based on King County's monthly sewer rate and the number of customers served by the local agency. In turn, the local agencies bill the residences, businesses and industries in their wastewater collection system to recover the county charge plus the amount needed to operate their local collection systems.

The 2016 monthly sewer rate is $42.03 for single-family residences. The charge for multifamily, commercial and industrial customers is $42.03 for each 750 cubic feet of water used.

Capacity charge

Since 1990, King County has levied a capacity charge on new connections to the sewer system, which these new customers pay in addition to their monthly sewer bill. The capacity charge helps King County cover the cost of sewer improvement and expansion projects needed to serve new growth.

Newly connecting customers are directly billed by King County for the capacity charge.

Elected officials, sewer utility representatives and jurisdiction officials were all involved in King County's decision to implement a capacity charge to ensure that "growth pays for growth." More about the Capacity Charge Program.

  2016 2017
County's wholesale monthly sewer rate $42.03 $44.22
Monthly capacity charge $58.70 $60.80

Ratepayer Report, April 2016
Ratepayer Report
, April 2016

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