Is tap water safe in Unalaska?

EPA SDWIS shows no active health-based violation in this profile's reporting window. That is not the same as proving every contaminant is absent, and federal data can lag state and utility records.

How hard is the water in Unalaska, AK?

There are not enough qualifying nearby USGS hardness observations for a responsible estimate. Test the home's tap or consult the serving utility.

Do I need a water softener in ZIP code 99685?

There is no high-hardness trigger in this profile. Confirm conditions with an at-home hardness test before purchasing equipment.

City water profile

Unalaska water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Unalaska, Alaska.

Median indexed hardness

—

2 indexed ZIPs

Range —–— PPM

State comparison: Unavailable
State hardness rank: —
Matched utilities: 1
Active health records: 0

City summary

What the indexed records say

Unalaska has 2 published ZIP profiles across Aleutians West Census Area. No qualifying nearby hardness observation is available for the city.

The —–— PPM range shows how much the available ZIP estimates vary within the city label.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs

Moderately hard0 ZIPs

Hard0 ZIPs

Very hard0 ZIPs

0 of 2 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance: — miles
Profiles with evidence: 0/2

Confidence labels

High: 0Moderate: 0Low: 0

Observation window: unavailable to unavailable.

ZIP directory

Water reports in Unalaska

Open a ZIP for site-level provenance and measurements.

ZIP code

99685

No estimate

—

Nearest site: — mi
Confidence: —

View full ZIP evidence →

ZIP code

99692

No estimate

—

Nearest site: — mi
Confidence: —

View full ZIP evidence →

Public water systems

Utilities associated with this city

Unalaska Water System

PWSID AK2260309

Surface water

System population served: 9,400
Last reported: Jun 19, 2026

The system names this served city; Census place overlap links the city to this ZCTA.

Compliance history

What EPA records show

No active health-based violation appears among the associated systems in the represented EPA reporting quarter. This does not mean every contaminant was tested at every tap.

Record	System	Period	Status
TTHM	AK2260309	Oct 1, 2025	Resolved
Total Haloacetic Acids (HAA5)	AK2260309	Oct 1, 2025	Resolved
Revised Total Coliform Rule	AK2260309	May 1, 2024	Resolved
Surface Water Treatment Rule	AK2260309	May 1, 2024	Resolved
Chlorine	AK2260309	May 1, 2024	Resolved
Total Haloacetic Acids (HAA5)	AK2260309	Jan 1, 2024	Resolved
Nitrate	AK2260309	Jan 1, 2024	Resolved
TTHM	AK2260309	Jan 1, 2024	Resolved
CARBON, TOTAL	AK2260309	Oct 1, 2023	Resolved
CARBON, TOTAL	AK2260309	Jul 1, 2023	Resolved

Practical next steps

Move from index to evidence

1. Open your ZIP. Check distance, dates, confidence, and the associated utility.
2. Read the current CCR. Confirm source water, detections, limits, ranges, and notices.
3. Test the tap when needed. Confirm health concerns or treatment sizing with the right method.

Continue comparing

Other Alaska communities

Adak

Aleutians West Census Area

— No median

Nikolski

Aleutians West Census Area

— No median

Anchorage

Anchorage Municipality

83 PPM median

Big Lake

Matanuska-Susitna Borough

83 PPM median

Coffman Cove

Prince Of Wales-Hyder Census Area

44 PPM median

Kake

Prince Of Wales-Hyder Census Area

59 PPM median

Search all 131 Alaska cities →

Questions people ask

About water in Unalaska

Is the water hard?

The index does not have a qualifying hardness estimate for this city.

Is the tap water safe?

Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.

Do I need treatment?

Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.