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
226–250 of 569Horizons West
WA5334375 · 3,454 served
Royal City Water
WA5374700 · 3,389 served
Dayton Water Department
WA5318250 · 3,374 served
City of Tenino
WA5387400 · 3,336 served
City of Newport
WA5359350 · 3,331 served
Algona Water Dept
WA5301450 · 3,300 served
City of Oroville
WA5364400 · 3,256 served
Fox Island Mutual Water Assoc
WA5326300 · 3,255 served
City of Brewster
WA5308300 · 3,235 served
City of Rock Island Water Dept
WA5373401 · 3,226 served
Ames Lake Water Assoc Inc
WA5302055 · 3,224 served
Toutle Community Regional Water
WA5388905 · 3,215 served
Strohs Water Company Inc
WA5384670 · 3,192 served
Lake Forest Park Water District
WA5340950 · 3,171 served
Highland Water District
WA5332850 · 3,121 served
Meadows 690
WA5387784 · 3,100 served
City of Napavine
WA5358200 · 3,095 served
Olympic Water & Sewer Inc
WA5368700 · 3,086 served
Snake River Housing Water System
WA5300710 · 3,036 served
Yacolt
WA5399000 · 3,034 served
Dry Creek Water Association
WA5320050 · 3,030 served
Carson
WA5311340 · 3,015 served
Fall City Water Dist. #127
WA5324550 · 2,987 served
Sno Pud 1 - Warm Beach
WA5393000 · 2,977 served
Clearwood
WA5313615 · 2,956 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