C42/100
KING COUNTY WATER DISTRICT NO 90 — Water Quality Report 2026
Serving 20,100 people · Washington
Water Source
Purchased Surface Water
County
—
System ID
WA5341150
Violations
47
Contaminant Test Results
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2024 – February 19, 2025Enforcement: Resolving — corrective action underway
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2021 – August 26, 2021Enforcement: Resolving — corrective action underway
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Frequently Asked Questions About KING COUNTY WATER DISTRICT NO 90
Is KING COUNTY WATER DISTRICT NO 90 water safe to drink?
KING COUNTY WATER DISTRICT NO 90 water receives a grade of C (42/100), which is considered fair. 0 contaminant(s) exceed EPA legal limits and 47 violation(s) are on record. Customers may want to consider using a water filter.
What contaminants has KING COUNTY WATER DISTRICT NO 90 detected?
69 contaminants were tested in KING COUNTY WATER DISTRICT NO 90's water. Notable contaminants include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 exceed EPA health goals (MCLGs).
Does KING COUNTY WATER DISTRICT NO 90 have any EPA violations?
Yes, KING COUNTY WATER DISTRICT NO 90 has 47 EPA violation(s) on record, with the most recent in 2024. Violation types include Other, MR, MCL. 2 are health-based violations.
How many people does KING COUNTY WATER DISTRICT NO 90 serve?
KING COUNTY WATER DISTRICT NO 90 serves approximately 20,100 people, Washington.
What type of water does KING COUNTY WATER DISTRICT NO 90 provide?
KING COUNTY WATER DISTRICT NO 90 sources its water from purchased surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is WA5341150.
How does KING COUNTY WATER DISTRICT NO 90 compare to other utilities in Washington?
KING COUNTY WATER DISTRICT NO 90 scores 42/100 with a grade of C (fair). This score indicates room for improvement compared to other utilities. Visit our Washington state page for a full comparison of water systems.