A88/100
MOUNTLAKE TERRACE CITY OF — Water Quality Report 2026
Serving 26,402 people · Washington
Water Source
Purchased Surface Water
County
—
System ID
WA5357250
Violations
12
Contaminant Test Results
EPA Violation History
1
Violation (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Surface water treatment technique failure
When: July 1, 2024 – February 20, 2025Enforcement: 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 MOUNTLAKE TERRACE CITY OF
Is MOUNTLAKE TERRACE CITY OF water safe to drink?
MOUNTLAKE TERRACE CITY OF water receives a grade of A (88/100), which is considered excellent. Out of 68 contaminants tested, none exceed EPA legal limits. The water meets federal safety standards.
What contaminants has MOUNTLAKE TERRACE CITY OF detected?
68 contaminants were tested in MOUNTLAKE TERRACE CITY OF's water. No contaminants exceed EPA legal limits or health goals, indicating good water quality management.
Does MOUNTLAKE TERRACE CITY OF have any EPA violations?
Yes, MOUNTLAKE TERRACE CITY OF has 12 EPA violation(s) on record, with the most recent in 2024. Violation types include Other, MR.
How many people does MOUNTLAKE TERRACE CITY OF serve?
MOUNTLAKE TERRACE CITY OF serves approximately 26,402 people, Washington.
What type of water does MOUNTLAKE TERRACE CITY OF provide?
MOUNTLAKE TERRACE CITY OF 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 WA5357250.
How does MOUNTLAKE TERRACE CITY OF compare to other utilities in Washington?
MOUNTLAKE TERRACE CITY OF scores 88/100 with a grade of A (excellent). This places it among the higher-performing utilities in the state. Visit our Washington state page for a full comparison of water systems.