A
89

US Water Score: A

Bothell, WA 98011

King County · Population served: 99,789 · Data updated July 2026

Service-area evidence: EPA service-area records associate the listed system with this ZIP. Boundaries may still overlap or change.

Water Systems Serving This Area

🏔
NORTHSHORE UTILITY DISTRICT
Surface water · Pop. 99,789
PWSID: WA5340800
🏔
WOODINVILLE WATER DISTRICT
Surface water · Pop. 66,699
PWSID: WA5341600
🏔
BOTHELL WATER CITY OF
Surface water · Pop. 33,643
PWSID: WA5307900

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
36.0
15 ppb 1 ppb

Violation History (Last 5 Years)

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

Water Quality Summary

Understanding Your Water in Bothell

Tap water quality in Bothell, Washington (98011) receives an overall grade of A (Lower record-based concern) with a score of 89 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 91. Compared to the national average (75), this area performs significantly better. The area is served by 3 water systems providing water to approximately 99,789 people, using surface water sources.

Your Score 89/100 A
vs State 2 pts below Washington avg (91)
vs National 14 pts above national avg (75)

What a Grade A Means

A score of 89/100 means public water-system records for Bothell, WA show relatively few concerns in the US Water Score model. This is an internal score, not an EPA safety rating, and it does not guarantee conditions at any specific tap.

Surface water: sourced from rivers, lakes, or reservoirs

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 public water-system records, Bothell, Washington receives an internal US Water Score grade of A (Lower record-based concern) with a score of 89/100. This indicates relatively few system-level concerns in our model, but it is not an EPA safety rating and does not guarantee tap conditions inside individual homes.

ZIP code 98011 is served by 3 water systems using surface water sources, providing water to approximately 99,789 people. Surface water systems are more susceptible to contamination from agricultural runoff, industrial discharge, and weather events, but typically undergo more extensive treatment including filtration and disinfection.

Lead levels in the public-system record for Bothell, Washington are 36.0 ppb, above the currently applicable EPA action level of 15 ppb. EPA's Lead and Copper Rule Improvements lower that action level to 10 ppb when the new requirements take effect. This system-level result does not measure an individual tap; consider a certified lead-removal filter and independent tap testing.

No PFAS ("forever chemicals") were detected in water systems serving Bothell, Washington during the most recent EPA monitoring period (UCMR5). However, not all water systems have been tested for all PFAS compounds, and new contamination can occur over time.

Water systems serving Bothell, 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), residents in Bothell, Washington should consider: NSF/ANSI 53 certified filter — specifically rated for lead reduction. Pitcher filters (like Brita Longlast or PUR) and under-sink systems both work. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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