AK / Unalaska
AK · Tap water records
Unalaska tap water, in plain English
Here is what the EPA's own data shows about tap water in Unalaska. According to EPA SDWIS data retrieved June 2026, Unalaska is served by 1 active community water system, together reported to serve about 9,400 people.
As of June 2026, EPA records show 48 violations across the community water system(s) serving Unalaska, going back to the earliest EPA record. None were health-based; the records are monitoring or reporting violations (a required test or report was late or missed). Each is listed by system below, with its status.
What the EPA has on record, by system
Unalaska Water System
9,400 served · surface water · PWSID AK2260309 - Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2024 and October 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2024 and October 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between May 2018 and May 2024. All have since returned to compliance, per EPA records.
- Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between April 2018 and May 2024. All have since returned to compliance, per EPA records.
- Monitoring Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 11 times between May 2018 and May 2024. EPA records do not show all of these as returned to compliance.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring CARBON, TOTAL: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times between July 2023 and October 2023. EPA records do not show all of these as returned to compliance.
- Monitoring Combined Uranium: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2017. EPA records do not show all of these as returned to compliance.
- Monitoring Gross Alpha, Excl. Radon and U: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2017. EPA records do not show all of these as returned to compliance.
- Monitoring Combined Radium (-226 and -228): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2017. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in October 2000. All have since returned to compliance, per EPA records.
What this means
A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.
This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.
Source: U.S. EPA Envirofacts SDWIS, retrieved June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.