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Washington Water Quality
569
Utilities in database
9.2M
Residents served
22%
On private wells
2
Key contaminants tracked
Drinking Water in Washington
Washington has 569 community water systems serving approximately 9.2 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, lead. 22% of Washington residents rely on private wells. DOH holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Washington
126–150 of 569City of Leavenworth
WA5346500 · 11,041 served
City of Grandview
WA5328970 · 11,010 served
City of Woodland
WA5398200 · 10,640 served
Manchester Water District
WA5350700 · 10,475 served
City of Orting
WA5364500 · 10,332 served
Lwwsd - South Shore Water System
WA5395910 · 10,028 served
Mountain View-edgewood Water Co
WA5356820 · 9,680 served
Fairchild Air Force Base
WA5324350 · 9,544 served
City of Airway Heights
WA5300650 · 9,489 served
Consolidated Irrig Dist 19 System 1
WA5310220 · 9,434 served
City of Chelan Water Dept
WA5312300 · 9,425 served
Ocean Shores Water Dept
WA5363008 · 9,347 served
City of Selah
WA5377400 · 9,331 served
Birch Bay Water & Sewer District
WA5395904 · 9,046 served
Toppenish Water Department
WA5388850 · 8,950 served
Port Angeles Composite
WA5343296 · 8,872 served
Othello Water Department
WA5364850 · 8,755 served
Union Hill Water Association Inc
WA5390260 · 8,720 served
Ephrata Water Department
WA5323650 · 8,718 served
Town of Steilacoom
WA5384000 · 8,545 served
Ne Sammamish Sewer & Water District
WA5375265 · 8,516 served
City of Quincy Water Department
WA5370450 · 8,415 served
Yak Co - Terrace Heights
WA5306029 · 8,410 served
College Place Water Dept
WA5314050 · 8,147 served
North Beach Water
WA5363000 · 8,093 served
Key Contaminant Concerns in Washington
Lead
Lead is a naturally occurring heavy metal that was widely used in plumbing infrastructure until it was banned for new installations in 1986. An estimated 9.2 million lead service lines still connect homes to public water mains across the United States, along with millions of homes with lead solder in their internal plumbing.
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
Washington Water FAQs
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Data source: Utility data from EPA SDWIS. 569 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-18