States ›Alaska ›Aleutians West Census Area ›Unalaska

Unalaska, AK Tap Water Quality 2026

Water quality report for Unalaska, AK — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Unalaska's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: Unalaska Water System PWSID: AK2260309 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead is 3.05 ppb, 20% of the action level and no violations are open. No PFAS was detected.

A

Unalaska earns an A for water quality

Graded on violations, lead, and PFAS, with state inspection findings.

Lead: 3.05 ppb — 20% of the federal action level
PFAS tested, none detected
27 violations since 2015, 0 health-based
No violations currently open
Unalaska's lead level vs. all Alaska community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 3.05 ppb — 20% of the federal action level
✓ Lower lead than 39% of Alaska utilities
Population Served
~603 connections
Water Source
Surface water
Drawn from surface water — SDWIS source code SW
Active Violations
0
27 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
20% of EPA action level
3.05 ppb
Action level: 15 ppb
Copper (Cu)
90th percentile of tap samples. SDWIS reports a copper figure only when a system exceeds the action level, so any value here is an exceedance.
106.2% of EPA action level
1,380 ppb
Action level: 1,300 ppb
The 90th-percentile lead result is 3.05 ppb, 20% of the 15 ppb federal action level. The action level is a treatment trigger, not a legal maximum, and it is measured across sampled taps rather than at any single home. Copper reached the action level here; a copper figure appears in SDWIS only when a system triggers it.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
TTHM MONITORING AND REPORTING — 0.080 mg/L 2025 Resolved
Total Haloacetic Acids (HAA5) MONITORING AND REPORTING — 0.060 mg/L 2025 Resolved
Revised Total Coliform Rule MONITORING FAILURE — — 2024 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2024 Resolved
Chlorine MONITORING AND REPORTING — 4.0 mg/L 2024 Resolved
TTHM MONITORING AND REPORTING — 0.080 mg/L 2024 Resolved
Total Haloacetic Acids (HAA5) MONITORING AND REPORTING — 0.060 mg/L 2024 Resolved
Nitrate MONITORING AND REPORTING — 10 mg/L 2024 Resolved
CARBON, TOTAL MONITORING AND REPORTING — TT 2023 Resolved
CARBON, TOTAL MONITORING AND REPORTING — TT 2023 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2022 Resolved
Revised Total Coliform Rule MONITORING FAILURE — — 2022 Resolved
Chlorine MONITORING AND REPORTING — 4.0 mg/L 2022 Resolved
Revised Total Coliform Rule MONITORING FAILURE — — 2021 Resolved
Revised Total Coliform Rule MONITORING FAILURE — — 2018 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2018 Resolved
Chlorine MONITORING AND REPORTING — 4.0 mg/L 2018 Resolved
Combined Uranium MONITORING AND REPORTING — 30 ug/L 2017–2025 Resolved
Combined Uranium MONITORING AND REPORTING — 30 ug/L 2017–2025 Resolved
Gross Alpha, Excl. Radon and U MONITORING AND REPORTING — 15 pCi/L 2017–2025 Resolved
Gross Alpha, Excl. Radon and U MONITORING AND REPORTING — 15 pCi/L 2017–2025 Resolved
Combined Radium (-226 and -228) MONITORING AND REPORTING — 5 pCi/L 2017–2025 Resolved
Combined Radium (-226 and -228) MONITORING AND REPORTING — 5 pCi/L 2017–2025 Resolved
Coliform (TCR) MONITORING AND REPORTING — 5% of samples 2015 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2015 Resolved
Surface Water Treatment Rule MONITORING AND REPORTING — — 2015 Resolved
Chlorine MONITORING AND REPORTING — 4.0 mg/L 2015 Resolved
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

27 violations are on record since 2015, of which 0 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Unalaska Water System
PWSID AK2260309
Water source Surface water — Drawn from surface water — SDWIS source code SW
Population served
Service connections 603
Systems serving this area 1
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Unalaska tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 3.05 ppb, 20% of the action level.
Does Unalaska water have PFAS? ▼
It was tested for the six regulated PFAS compounds and none were detected.
Who supplies water to Unalaska? ▼
Unalaska Water System (PWSID AK2260309). Surface water. Drawn from surface water — SDWIS source code SW
When was this system last inspected? ▼
It was last inspected on 2025-09-16. No significant deficiencies were recorded.

What Should Unalaska Residents Do?

1
Read your annual water report
Your supplier publishes a Consumer Confidence Report each July covering the prior year.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

Nearby Cities in Alaska

Adak, Ak Tap Water Quality 2026 Aleutians West Census Area Atka, Ak Tap Water Quality 2026 Aleutians West Census Area St. George, Ak Tap Water Quality 2026 Aleutians West Census Area St. Paul, Ak Tap Water Quality 2026 Aleutians West Census Area