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MOUNTLAKE TERRACE CITY OF vs SEATTLE PUBLIC UTILITIES

Water quality comparison — risk levels, violations, PFAS records, and contaminants

Quick Answer

Both utilities share the same risk level (safe). MOUNTLAKE TERRACE CITY OF has 0 open health-based violations and 116 PFAS records. SEATTLE PUBLIC UTILITIES has 0 open health-based violations and 232 PFAS records.

MOUNTLAKE TERRACE CITY OF

Washington · WA5357250

Overall Risk Level

No Concerns Detected

No Concern
Low
Moderate
High
Critical

Water meets all safety standards with no detected exceedances.

0

Open violations

116

PFAS records

SEATTLE PUBLIC UTILITIES

Washington · WA5377050

Overall Risk Level

No Concerns Detected

No Concern
Low
Moderate
High
Critical

Water meets all safety standards with no detected exceedances.

0

Open violations

232

PFAS records

Head-to-Head Comparison

MetricMOUNTLAKE TERRACE CITY OFSEATTLE PUBLIC UTILITIES
StateWashingtonWashington
Risk LevelNo Concerns DetectedNo Concerns Detected
Population Served26,4021,161,961
Open Health Violations00
Total Violations131
PFAS Records116232
OwnershipLocalLocal
Service TypeSurface waterSurface water
City ServedSeattle

Contaminants in Violation Records

MOUNTLAKE TERRACE CITY OF

  • Haloacetic Acids (HAA5)
  • Total Trihalomethanes (TTHMs)
  • Nitrate

SEATTLE PUBLIC UTILITIES

No named contaminants in violation records.

Key Differences

MOUNTLAKE TERRACE CITY OF has 116 PFAS records vs. 232 for SEATTLE PUBLIC UTILITIES.

What Should I Do?

If either utility shows open violations or elevated PFAS records, consider:

  • Installing a reverse osmosis filter — removes PFAS, lead, arsenic, nitrates, and most heavy metals.
  • Requesting your utility’s annual Consumer Confidence Report (CCR) for the most current test results.
  • Ordering a certified lab water test if you want contaminant-specific data for your address.

Frequently Asked Questions

Which is safer — MOUNTLAKE TERRACE CITY OF or SEATTLE PUBLIC UTILITIES?

Both utilities share the same risk level (safe). Both utilities have similar violation profiles — review the full data above to decide based on specific contaminants that concern you.

What does "open health-based violation" mean?

An open health-based violation means a water system has exceeded an EPA Maximum Contaminant Level (MCL) or failed to meet a treatment technique — and the violation has not yet been resolved. These are the most serious type of water quality violations.

How current is this data?

Violation data comes from EPA's Safe Drinking Water Information System (SDWIS), which is updated as utilities report. PFAS data comes from EPA's UCMR 5 monitoring (2023–2025). Risk levels are recalculated daily.

What does PWSID mean?

PWSID stands for Public Water System ID — a unique federal identifier assigned to each community water system. You can use it to look up a system in EPA's ECHO database.

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