MT / Colstrip
MT · Tap water records
Colstrip tap water, in plain English
Here is what the EPA's own data shows about tap water in Colstrip. According to EPA SDWIS data retrieved June 2026, Colstrip is served by 1 active community water system, together reported to serve about 2,350 people.
As of June 2026, EPA records show 28 violations across the community water system(s) serving Colstrip, going back to the earliest EPA record. 6 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.
What the EPA has on record, by system
Colstrip City Of
2,350 served · surface water · PWSID MT0000180 - Health-based Surface Water Treatment Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times in July 2024. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
- Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times in July 2024. The EPA record lists a level of 81 UG/L; the limit (MCL) is 80 UG/L. EPA records do not show all of these as returned to compliance.
- Monitoring Surface Water Treatment Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 13 times in January 2024. EPA records do not show all of these as returned to compliance.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in July 2023. 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 in July 2023. 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 2 times in May 2022. All have since returned to compliance, per EPA records.
- 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 2001. 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.