B
74

Good Water Quality

Redmond, WA 98053

King County · Population served: 311,290 · Data updated March 2026

Water Systems Serving This Area

🏔
SAMMAMISH PLATEAU WATER & SEWER
Surface water · Pop. 79,362
PWSID: WA5340900
🏔
WOODINVILLE WATER DISTRICT
Surface water · Pop. 59,873
PWSID: WA5341600
🏔
REDMOND WATER SYSTEM CITY OF
Surface water · Pop. 163,335
PWSID: WA5371650
🌊
UNION HILL WATER ASSOCIATION INC
Groundwater · Pop. 8,720
PWSID: WA5390260

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
3.6
15 ppb 1 ppb Warning

PFAS / Forever Chemicals

8 detected 3 above EPA limits
CompoundLevelEPA MCLHealth GuidelineStatus
PFHxS16.5 ppt10 ppt10 pptExceeded
PFOS11.1 ppt4 ppt4 pptExceeded
PFBS8.8 ppt2000 ppt100 pptBelow limit
PFBS5.0 ppt2000 ppt100 pptBelow limit
PFOS5.0 ppt4 ppt4 pptExceeded
PFHxA4.3 pptNo standard400 pptUnregulated
PFPeS4.1 pptNo standardUnregulated
PFPeA3.9 pptNo standardUnregulated

Violation History (Last 5 Years)

1Total (5yr)
0Health-Based
1Major

Water Quality Summary

Understanding Your Water in Redmond

Tap water quality in Redmond, Washington (98053) receives an overall grade of B (Good) with a score of 74 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is roughly in line with the Washington state average of 76. The area is served by 4 water systems providing water to approximately 311,290 people, using surface water and groundwater sources. Testing has found elevated levels of Lead that warrant attention. Notably, 3 PFAS compounds exceed EPA limits — a significant concern given the persistent nature of these chemicals.

Your Score 74/100 B
vs State 2 pts below Washington avg (76)
vs National 1 pts below national avg (75)

What a Grade B Means

A score of 74/100 means the water in Redmond, WA is generally good and meets EPA standards, with only minor areas of concern. There may be low levels of detectable contaminants or a small number of non-critical violations. Most residents can feel comfortable with their tap water quality, though basic filtration can provide an extra layer of protection.

Surface water: sourced from rivers, lakes, or reservoirs
Groundwater: drawn from underground aquifers via wells

Health Information

What These Contaminants Mean for You

⚠️

Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

Common Questions

Frequently Asked Questions

Based on EPA data, tap water in Redmond, Washington receives a grade of B (Good) with a score of 74/100. This indicates the water meets federal standards and has relatively few concerns. However, individual homes may still have localized issues such as lead from old plumbing.

ZIP code 98053 is served by 4 water systems using surface water, groundwater sources, providing water to approximately 311,290 people. Multiple source types mean your water may come from a blend of surface and underground sources.

Lead was detected at 3.6 ppb in Redmond, Washington. While this is below the EPA action level of 15 ppb, it exceeds the health guideline of 1 ppb recommended by health organizations. Consider a certified lead filter, especially if you have young children.

Yes — 8 PFAS compounds were detected in water serving Redmond, Washington, and 3 exceed EPA maximum contaminant levels. PFAS are persistent chemicals linked to cancer, immune system effects, and developmental issues. A reverse osmosis or activated carbon filter certified for PFAS removal is recommended.

Water systems serving Redmond, Washington have received 1 violation in the last 5 years. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

Based on detected contaminants (lead, PFAS), residents in Redmond, Washington should consider: Reverse osmosis (RO) system — most effective for PFAS, lead, and other contaminants. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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