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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
451–475 of 569Country/eldorado Water System
WA5315522 · 915 served
Lake Lawrence
WA5322572 · 914 served
Town of Lind
WA5347350 · 903 served
Scatchet Head Water District
WA5376470 · 900 served
Solmar Water
WA5381315 · 895 served
Island Lake
WA5336150 · 883 served
Carbonado Water Dept
WA5311100 · 875 served
Rolling Hills-glencairn
WA5374000 · 872 served
Lake of the Woods Community Club
WA5344387 · 870 served
Adams County Water Dist #1
WA5322525 · 870 served
Admirals Cove Water District
WA5300410 · 870 served
Town of Pe Ell
WA5366750 · 859 served
Town of Rosalia
WA5374250 · 831 served
Hangman Hills Water Dist 15
WA5330848 · 827 served
Camaloch Association
WA5310580 · 825 served
Concrete Utilities
WA5303950 · 810 served
Diamond Point
WA5319210 · 810 served
Town of St John
WA5375300 · 800 served
Rosedale East
WA5309490 · 798 served
Whatcom County Water Dist 13
WA5395914 · 795 served
Western Wahkiakum
WA5395167 · 791 served
Valle Lindo Homes
WA5392475 · 787 served
Sno Pud 1 - Storm Lake Ridge
WA5344431 · 786 served
Veterans Affair Med Ctr Dept of
WA5390542 · 785 served
Hillcrest Village Water Co Inc
WA5333150 · 770 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