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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
476–500 of 569Scenic Shores Water Company
WA5376530 · 761 served
Northgate Terrace Community Club
WA5361750 · 750 served
Lewis Co Water Sewer Dist #6
WA5344240 · 740 served
Lake Holiday Association
WA5383600 · 740 served
Lost Lake Property Owners Assn
WA5348345 · 736 served
Stevens Co Pud - Clayton
WA5313450 · 725 served
Lynch Cove
WA5349100 · 721 served
Sun Cove Public Water System
WA5385124 · 716 served
Larch Corrections Center
WA5306461 · 705 served
Lyman Water Department
WA5349050 · 705 served
Union
WA5351920 · 700 served
Kittitas County Water District #5
WA5342704 · 699 served
Oak Park
WA5362675 · 695 served
Garfield Water Department
WA5327200 · 694 served
Mcneil Island Water
WA5352900 · 692 served
Grandview Condominiums
WA53AE050 · 679 served
Town of Cusick
WA5317000 · 672 served
Wilderness Ridge Community Club
WA5396876 · 664 served
Chinook Water District
WA5312800 · 664 served
Great Basin Water Burbank
WA5331477 · 656 served
Del Mar Community Service
WA5318580 · 654 served
Three Lakes Water District
WA5388140 · 650 served
City of Harrington
WA5331450 · 650 served
Vistaire Water System
WA5357414 · 647 served
Washington Soldiers Home Colony
WA5364700 · 643 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