Unalaska Water System
EPA ID: AK2260309 · 9,400 people served · 3 ZIP codes
Unalaska Water System carries 11 resolved violations in the five-year EPA record — each has been formally closed, and the supplier, which serves approximately 9,400 people, now meets all applicable federal drinking water standards with no open enforcement activity remaining.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Unalaska Water System Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The Unalaska Water System serves a community with a median household income of $108,750 and an estimated 4,489 residents across its service area. Approximately 53% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Unalaska Water System's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
About 4% of homes in Aleutians West Census Area, Alaska rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
Detected Contaminants
How Unalaska Water System compares to EPA limits
What This Means For You
Lead at 1 mg/L (action level) exceeds the EPA maximum of 0.015 mg/L (action level). Brain damage in children, kidney & blood pressure in adults. Consider reverse osmosis filtration.
Total Trihalomethanes (TTHM) at 1 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Consumer Confidence Report Rule at 3 mg/L exceeds the EPA maximum of mg/L.
Chlorite at 2 mg/L exceeds the EPA maximum of 1 mg/L. Anemia and nervous system effects in infants and children. Consider ferrous sulfate reduction filtration.
E. coli at 2 Zero tolerance (any positive sample triggers immediate action) exceeds the EPA maximum of Zero tolerance (any positive sample triggers immediate action). Severe GI illness; potentially fatal kidney failure in children. Consider UV disinfection (99.99%) filtration.
Lead was detected in this water system. reverse osmosis filtration can reduce exposure.
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System Overview
UNALASKA WATER SYSTEM (EPA ID: AK2260309) is a community water system in Alaska that serves approximately 9,400 people from surface water sources.
This system provides water to 3 ZIP codes across 3 communities.
Average Home Safety Score: C (65/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| May 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| May 1, 2024 | E. coli | Monitoring | Resolved |
| May 1, 2024 | Revised Total Coliform Rule | Monitoring | Resolved |
| January 1, 2024 | Total Trihalomethanes (TTHM) | Monitoring | Resolved |
| January 1, 2024 | Lead | Monitoring | Resolved |
| October 1, 2023 | Chlorite | Monitoring | Resolved |
| July 1, 2023 | Chlorite | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting Failure | 3 | No |
| Chlorite | Disinfection Byproducts | 2 | No |
| E. coli | Microbiological | 2 | No |
| Revised Total Coliform Rule | Microbiological | 2 | No |
| Lead | Inorganic | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 99685 | 0.00305 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Unalaska Water System (AK2260309) on EPA.gov.
Frequently Asked Questions
Is Unalaska Water System water safe to drink?
Unalaska Water System has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Unalaska Water System serve?
Unalaska Water System serves approximately 9,400 people across 3 ZIP codes in Alaska.
Where does Unalaska Water System get its water?
The primary water source is surface water.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: UNALASKA WATER SYSTEM Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Federal UCMR5 PFAS Monitoring: Tested Clean
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). No PFAS compounds were detected.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Unalaska Water System (EPA ID: AK2260309) — request the latest Consumer Confidence Report or ask about specific contaminants.