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
301–325 of 569Three Lakes Water Association
WA5388150 · 2,198 served
Alderbrook Water Co
WA5301050 · 2,154 served
City of Mabton
WA5349650 · 2,150 served
Lake Limerick Water
WA5344150 · 2,148 served
City of Morton
WA5356250 · 2,147 served
Lakeland Village Water
WA5345090 · 2,120 served
Sunnyslope
WA5385550 · 2,112 served
City of Roslyn
WA5374400 · 2,099 served
Sandy Point Improvement Co
WA5376105 · 2,098 served
Roche Harbor Water System Inc
WA5373230 · 2,091 served
Mirrormont
WA5355250 · 2,083 served
Naselle
WA5358350 · 2,073 served
View Royal Water System
WA5328494 · 2,069 served
Heights Water
WA5332300 · 2,051 served
Nisqually Pines Community Club
WA5359591 · 2,037 served
Deer Creek Water Assoc.
WA5318418 · 2,000 served
Lewis Co Water Dist #2
WA5347001 · 1,983 served
Clinton Water District
WA5313900 · 1,980 served
Skagit Co Water District #1
WA5300392 · 1,974 served
Toledo Municipal
WA5388660 · 1,944 served
City of Millwood
WA5354850 · 1,925 served
Palmer Lake
WA5365745 · 1,924 served
Anacortes - Fidalgo
WA5300932 · 1,890 served
Summit View Water System
WA5303303 · 1,869 served
Wilderness Rim Association
WA5396878 · 1,867 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