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
276–300 of 569Willapa Valley Water District
WA5397100 · 2,425 served
Cherokee Bay Community Club Inc
WA5311626 · 2,400 served
City of Carnation Water System
WA5311200 · 2,400 served
Soap Lake Water Dept
WA5381300 · 2,399 served
Ione Water Dept
WA5335900 · 2,395 served
Tonasket Water System
WA5388700 · 2,392 served
Boistfort Valley
WA5307610 · 2,389 served
Glacier Water District
WA5395915 · 2,383 served
Pacific Beach/moclips
WA5300333 · 2,372 served
Crescent Water Assn
WA5316020 · 2,360 served
Timberlake Community Club Inc
WA5388370 · 2,337 served
Badger Mountain Irrigation District
WA5322617 · 2,331 served
Jackson Park Naval Hospital
WA5305345 · 2,277 served
Valley Water System
WA5301250 · 2,259 served
Alpine Water District
WA5325315 · 2,255 served
West Kitsap
WA5308367 · 2,248 served
City of Kittitas
WA5342650 · 2,247 served
Town of Darrington
WA5317950 · 2,246 served
Sunland Water District
WA5385260 · 2,235 served
Washington Corrections Center
WA5393063 · 2,223 served
City of Bridgeport
WA5308350 · 2,214 served
North Spokane Irrigation District 8
WA5361300 · 2,214 served
Cle Elum Water Department
WA5313500 · 2,213 served
Shelter Bay Community Inc
WA5378155 · 2,212 served
Hutchinson Irrigation Dist #16
WA5335100 · 2,209 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