Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Washington Water Quality Reports
Water quality scores for 4 cities in Washington
Seattle
1,600,000 residents
Spokane
230,000 residents
Tacoma
320,000 residents
Vancouver
280,000 residents
About Washington Water Quality
Washington State benefits from abundant rainfall and snowmelt that provides generally high-quality source water. The Seattle area's protected watershed system produces excellent tap water. However, some communities face challenges with naturally occurring contaminants and agricultural impacts in eastern Washington.
Based on our analysis of 4 cities in Washington, the average water quality score is 95/100. The highest-rated city is Vancouver with a score of 95/100, while Seattle has the most room for improvement at 95/100.
Water Sources in Washington
Seattle's water comes from the protected Cedar and Tolt River watersheds in the Cascade Mountains. Other Puget Sound communities draw from rivers and reservoirs. Eastern Washington relies more heavily on groundwater and agricultural area surface water. Groundwater quality varies significantly by region.
Common Water Contaminants in Washington
These contaminants have been detected in various Washington water systems
Washington Water Regulations
Washington State Department of Health manages drinking water programs. The state has established notification requirements for PFAS and other emerging contaminants. Washington's water quality standards are protective, and the state invests significantly in source water protection.
Health Considerations
Western Washington generally enjoys excellent water quality, though older homes may have lead concerns. Eastern Washington agricultural areas should monitor nitrate levels. Some areas have naturally occurring arsenic in groundwater. PFAS contamination has been identified near military bases and airports.
Recommendations for Washington Residents
Washington residents in older homes should test for lead. Eastern Washington residents should consider activated carbon filtration for agricultural chemicals and nitrate removal systems if levels are elevated. Seattle area residents enjoy some of the nation's best tap water but should address any lead plumbing in older homes.
Frequently Asked Questions About Washington Water Quality
Is Washington's tap water safe to drink?
Most Washington cities have tap water that meets EPA safety standards. With an average score of 95/100 across 4 cities we analyzed, Washington generally has good water quality. However, water quality varies by location, so check your specific city's report.
What are the main water quality concerns in Washington?
The most common water quality concerns in Washington include lead (older infrastructure), nitrates (eastern agricultural areas), arsenic (some groundwater). These contaminants can come from natural sources, industrial activities, or aging infrastructure. Review your city's specific report to see which contaminants affect your area.
Should I use a water filter in Washington?
Whether you need a water filter depends on your specific location and health concerns. Most Washington cities have water that meets EPA standards, though some residents prefer additional filtration for taste or extra protection. Look for filters certified by NSF/ANSI to remove the specific contaminants found in your area.
Where can I find my Washington water quality report?
Public water systems in Washington are required to provide annual Consumer Confidence Reports (CCRs) to residents. You can usually find your report on your water utility's website, request it by phone, or access it through the EPA's database. Our city-level reports above summarize key information from these official sources.