Water Quality in Unalaska, AK: 11 Violations - Grade A
Grade A · Score 94/100 · 1 water system · Updated 2026-07-18
Unalaska's water meets all EPA standards with no health-based violations.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-07-18
Unalaska in AK has 11 EPA water violations documented - the compliance history below covers what was flagged and which local systems are associated with each finding.
Water Quality by ZIP Code in Unalaska
Unalaska is covered by a single ZIP code, so one water-quality profile applies citywide. See the contaminant data below.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 99685 | A | 94 | 11 | 0 | View report → |
Water Quality Overview
Unalaska, Alaska receives a water quality grade of A with an overall score of 94 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 1 water system serving Unalaska have accumulated 11 EPA violations (all monitoring/reporting type). These violations are tracked across 1 ZIP code serving approximately 3,690 people.
What Grade A Means
A grade of A indicates excellent compliance with EPA drinking water standards. Unalaska's water systems have maintained strong performance in both contaminant monitoring and regulatory compliance.
Lead Levels
The average 90th percentile lead level across Unalaska water systems is 0.0031 mg/L - within EPA limits. No ZIP codes exceed the EPA lead action level.
Water Systems Serving Unalaska
Unalaska is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 3,690 people across 1 ZIP code.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 10 enforcement actions against water systems serving Unalaska. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Unalaska
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR - your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test - certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration - NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories - monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Unalaska Water Systems
The following contaminants have been detected or caused violations across Unalaska's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| E. coli | Microbiological | N/A | 2 | 1 | No |
| Revised Total Coliform Rule | Microbiological | N/A | 2 | 1 | No |
| Chlorite | Disinfection Byproducts | 1 mg/L | 2 | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
| Lead | Inorganic | 0.015 mg/L | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Unalaska. Recent actions:
| Date | Action Type |
|---|---|
| 2025-12-09 | State Informal Action |
| 2025-11-05 | State Informal Action |
| 2025-07-16 | State Informal Action |
| 2025-06-05 | State Informal Action |
| 2025-05-13 | State Informal Action |
| 2025-04-21 | State Order Extension |
| 2024-12-23 | State Order Extension |
| 2024-09-25 | State Informal Action |
| 2024-08-09 | State Informal Action |
| 2024-06-24 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-12-09.
Unalaska vs. Nearby Alaska Cities
How Unalaska's water quality compares to similar cities in Alaska:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Unalaska | A | 11 | 1 | 3,690 |
| Valdez | A | 0 | 4 | 3,935 |
| Petersburg | A | 3 | 1 | 3,394 |
| Big Lake | B | 12 | 5 | 4,066 |
Common Questions About Unalaska Water
These are the most common questions residents search for about water quality in Unalaska, Alaska:
Is Unalaska water hard or soft? Water hardness varies by source. Unalaska's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Unalaska tap water? Unalaska's water receives a grade of A (94/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Unalaska? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Unalaska vs. Alaska Average
Understanding how Unalaska compares to the broader Alaska average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below - water quality can vary significantly even within Unalaska.
ZIP Codes in Unalaska
Unalaska spans 1 ZIP code. The ZIP with the lowest water quality score is 99685. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.
Frequently Asked Questions
Your Water is Safe - Here's How to Keep It That Way
Grade A is excellent news. Here's what proactive homeowners do to maintain water quality:
Annual Water Testing
EPA recommends annual testing even with clean water. Home test kits: $20-$50. Catches changes before they become problems.
Maintenance Filtration
A basic carbon filter removes chlorine taste and catches emerging contaminants like PFAS that aren't yet fully regulated.
Plumbing Check
Even safe city water picks up lead from home pipes. If your home was built before 1986, a one-time pipe inspection is recommended.