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
401–425 of 569Monse-riggan Camp
WA53AC141 · 1,165 served
Weiler-martin Tracts Water Assn
WA5394110 · 1,163 served
Basin Water Sources Inc
WA5304600 · 1,158 served
Meadowmeer
WA5353275 · 1,157 served
Boston Harbor
WA5307850 · 1,153 served
Pateros Water Department
WA5366450 · 1,149 served
Newberry Hill
WA5306136 · 1,143 served
Ashford Water District
WA5303200 · 1,141 served
Town of Waterville
WA5393600 · 1,140 served
Quistorff
WA5370550 · 1,113 served
W&b Waterworks 1
WA5346670 · 1,112 served
Crescent Bar System
WA5315950 · 1,108 served
Beards Cove
WA5305100 · 1,100 served
City of Tekoa
WA5387300 · 1,076 served
Sunshine Acres
WA5386250 · 1,074 served
Miller Bay
WA5354683 · 1,072 served
Wilkeson Water Department
WA5396950 · 1,071 served
Camano Co-op Water & Power Co
WA5310600 · 1,071 served
Town of Twisp
WA5390050 · 1,055 served
Holiday Ranchettes
WA5333677 · 1,050 served
City of North Bonneville
WA5360150 · 1,048 served
Fawn Lake Maintenance Comm
WA5324713 · 1,044 served
Estates Inc
WA5308166 · 1,043 served
Town of Wilbur
WA5396800 · 1,040 served
City of George
WA5327395 · 1,035 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