Public water system record
City of Colstrip
Serves Colstrip, Rosebud County, MT · 2,350 people served
Federal records show 2 health-based violations and 6 monitoring/reporting issues for City of Colstrip in the last ten years. The most serious issue in this window was a resolved Total Trihalomethanes (TTHMs) violation.
System profile
- Health-based violations, last 10 years
- 2
- Resolved
- 2
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 6
Key facts
- City of Colstrip draws water from 1 surface water intake.
- Highest measured level in the last 10 years: Total Trihalomethanes (TTHMs), 81 µg/L, federal limit 80 µg/L (at or just above the limit), 2024.
- Record on file since 1993, with 0 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 52 unknown out of 1,141 service lines.
Check whether City of Colstrip serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
| Contaminant | Rule family | Start date | Status | Acute |
|---|---|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 81 µg/L, federal limit 80 µg/L (at or just above the limit)
|
220 | Jul 1, 2024 | Resolved | No |
|
Surface Water Treatment Rule
Treatment technique failure
|
120 | Jul 1, 2024 | Resolved | No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Surface Water Treatment Rule
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Jan 1, 2024 | Resolved |
|
Haloacetic Acids (HAA5)
Monitoring and reporting
|
Jul 1, 2023 | Resolved |
|
Total Trihalomethanes (TTHMs)
Monitoring and reporting
|
Jul 1, 2023 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
May 1, 2022 | Resolved |
Full record since 1993
EPA's records for City of Colstrip go back to 1993. Before October 19, 2016 they list no health-based violations and 47 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1990s | 0 | 25 |
| 2000s | 0 | 21 |
| 2010 to October 18, 2016 | 0 | 1 |
| 2020s | 2 | 6 |
What the violations mean
Total Trihalomethanes (TTHMs)
1 incidentDisinfection byproduct levels exceeded the federal limit
Long-term TTHM exposure may increase bladder cancer risk
Surface Water Treatment Rule
1 incidentThe system did not complete a treatment step or action that the Surface Water Treatment Rule requires (a treatment technique violation).
The utility had to notify customers about this violation.
Where the water comes from
City of Colstrip draws water from 1 surface water intake. 1 smaller public system such as schools, businesses or campgrounds buys water from City of Colstrip.
Annual water quality report
City of Colstrip must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Where the state allows it, systems serving fewer than 10,000 people may publish the report in a local newspaper or news site instead of mailing it, and must provide a copy on request.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by Montana.
Certified drinking water labs by state EPA guidance for private wells