Washington Water Quality Report
Tap water quality data for 22 cities in Washington, updated 2026.
US average: 100 ppm
21 of 22 cities violation-free
21 cities tested
22 water systems tracked
Cleanest Tap Water in Washington
Cities with the fewest water quality issues
Seattle
1.1M served
Tacoma
449K served
Vancouver City of
373K served
Spokane City of
343K served
Bellevue City of
317K served
Everett Public Works Dept. City of
216K served
Alderwood
200K served
Kent
157K served
Redmond
148K served
Bellingham-water Division City of
140K served
Most Water Quality Issues in Washington
Cities with the most violations and concerns
Water Hardness Across Washington
Not sure what your hardness means? Use our Water Hardness Calculator or find the best hardness test kits.
Washington Tap Water: What You Need to Know
Washington has 22 tracked water utilities serving approximately 4.8M residents. The average water hardness is 56 ppm (3.3 GPG), classified as Soft — below the national average of 100 ppm. Hardness ranges from 21.8 ppm in Spokane City of to 310 ppm in Pasco.
In the past 3 years, 1 of 22 cities in Washington have recorded water quality violations, totaling 2 violations (0 health-based). All 21 tested cities have lead levels below the EPA action level of 15 ppb.
Frequently Asked Questions About Washington Water
Is tap water safe to drink in Washington?
Most tap water in Washington meets EPA standards, but 1 cities have recorded violations in the past 3 years (0 health-based). We recommend checking your specific city's report on TapWater.org and considering a home water test.
How hard is the water in Washington?
Washington's average water hardness is 56 ppm (3.3 GPG), classified as Soft. This is below the national average of 100 ppm. Hardness varies significantly by city — use our Water Hardness Calculator to check your specific area.
Which city in Washington has the cleanest tap water?
Based on EPA violation data, lead testing, and water quality metrics, Seattle ranks as having the cleanest tap water in Washington. It has zero violations in the past 3 years and lead levels well below the EPA action level.
Which city in Washington has the most water quality issues?
Kennewick City of currently has the most water quality concerns in Washington, with 2 violations in the past 3 years. Residents should check their city's detailed water quality report and consider using a certified water filter.
Where does Washington get its water from?
The majority of Washington's water systems (68%) use surface water as their primary source. Surface water comes from rivers, lakes, and reservoirs. Each city's specific source can vary — check individual city reports for details.
Largest Cities in Washington
The 16 biggest utilities by population served — hardness, lead status, and violations at a glance
Seattle
Utility serves 1.1M
Tacoma
Utility serves 449K
Vancouver City of
Utility serves 373K
Spokane City of
Utility serves 343K
Bellevue City of
Utility serves 317K
Everett Public Works Dept. City of
Utility serves 216K
Alderwood
Utility serves 200K
Kent
Utility serves 157K
Redmond
Utility serves 148K
Bellingham-water Division City of
Utility serves 140K
Lakehaven
Utility serves 118K
Clark
Utility serves 117K
Pasco
Utility serves 116K
Highline
Utility serves 116K
Kennewick City of
Utility serves 114K
Olympia City of
Utility serves 114K
More Cities in Washington
All 22 covered cities, A–Z