Performance of Rapid Rate Filtration Plants in Washington

Optimizing rapid rate filter performance for turbidity (particle) removal provides better public health protection for consumers.

Each month, rapid rate treatment plants across the state submit operations reports to document regulatory compliance. We enter maximum daily turbidity values from the 55 active treatment plants into Optimization Assessment Software and rank systems according to their relative performance.

Washington State Rapid Rate Treatment Plant Performance Trends (PDF) shows turbidity reduction performance improvement by all rapid rate treatment plants in Washington as a group from 2001 through 2023. Improved performance means improved public health protection. Read more about optimization criteria (PDF).

By optimizing water quality produced by their existing facilities, these utilities are able to cost-effectively provide a larger margin of safety and build greater resiliency to handle natural disasters and other unforeseen events.

Congratulations 2023 TOP Performers!

Turbidity monitoring data for 2023 show that Washington's conventional and direct filtration surface water treatment plants continue to perform above national regulatory standards—and provide better public health protection.

Four systems are continuing their run of excellence and have now reached 23 consecutive years of optimization!

We also award bronze, silver, gold, and platinum certificates to systems the first time they meet the turbidity goals for 3, 5, 10, and 15 consecutive years, respectively. This year, one system earned a platinum award, two systems earned a silver award, and two systems earned a bronze award.

See a complete list of systems that met optimization goals in 2023.

Congratulations to the treatment plant operators, utility managers, and decision makers for making this happen!

Twenty-Year Award

  • Arlington Water Department (2001-2023)
  • Lake Whatcom Water and Sewer District—South Shore Water System (2001-2023)
  • Pasco Water Department (2001-2023)
  • Skagit County PUD #1—Judy Reservoir System (2001-2023)

Platinum Award Recipients (15 or more years)

  • City of Kelso (2006-2023)
  • River Bend Water System (2009-2023)*

Gold Award Recipients (10 to 14 years of continuously optimized performance)

  • City of Yakima (2010-2023)
  • City of Bellingham (2011-2023)
  • Castle Rock Municipal Water (2012-2023)^
  • Town of Metaline Falls (2012-2023)

Silver Award Recipients (Five to nine years of continuously optimized performance)

  • Department of Energy/200 W (2015-2023)
  • Hoquiam Water Department (2015-2023)
  • Lake Chelan Reclamation District (2015-2023)
  • City of Anacortes (2016-2023)
  • Friday Harbor (2017-2023)
  • Raymond Water Department (2017-2023)
  • Seattle Public Utilities (2019-2023)*
  • City of Port Angeles (2019-2023)*

Bronze Award Recipients (Three or four years of continuously optimized performance)

  • City of Everett Public Works Department (2021-2023)*
  • City of Ilwaco Water Department (2021-2023)*
  • Roche Harbor Water System (2020-2023)
  • City of Leavenworth (2020-2023)
  • Water District 19 (2020-2023)

*First-time award recipient for 2023.
^Data error from 2022 correction.

Get the information and assistance you need to improve treatment plant performance by contacting your regional ODW office.

Eastern Regional Office, Russell Mau 509-329-2116

Northwest Regional Office, Laura McLaughlin 564-669-0753

Southwest Regional Office, Scott Pollock 564-669-0854