State Hub
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
251–275 of 569Cedar Crest
WA5311887 · 2,954 served
South Bend Water Department
WA5381500 · 2,930 served
City of Okanogan Water Department
WA5363200 · 2,921 served
Erland Point Water Co
WA5323850 · 2,909 served
Stevens Co Pud - Deer Lake
WA5393380 · 2,884 served
Western State Hospital
WA5395150 · 2,857 served
Desert Aire Owner Assn
WA5319056 · 2,856 served
Mccormick Woods
WA5340529 · 2,760 served
West Sequim Bay Inc
WA5354192 · 2,759 served
Rainier Water Department
WA5370980 · 2,758 served
City of Ilwaco Water Department
WA5335500 · 2,757 served
City of Mccleary
WA5352250 · 2,753 served
City of Gold Bar
WA5328300 · 2,745 served
Kettle Falls Water Dept
WA5338400 · 2,698 served
Surfside Homeowners
WA5386470 · 2,687 served
Olympic Mall
WA5363479 · 2,681 served
Columbia Valley Water District
WA5366110 · 2,648 served
Suncadia Resort
WA53AA317 · 2,640 served
Chewelah Water Dept South
WA5312750 · 2,615 served
Stevenson Water Dept
WA5384250 · 2,594 served
Camano Water Association
WA5310750 · 2,592 served
Asotin Water Dept
WA5303250 · 2,531 served
Stevens Co Pud - Loon Lake
WA5348250 · 2,487 served
Malaga Water District
WA5350500 · 2,478 served
Nooksack Water Dept
WA5359800 · 2,427 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
Quick Links
Data source: Utility data from EPA SDWIS. 569 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-18