Community Water System · PWS MT0000180
Colstrip City Of
Operator location Colstrip, Montana - upper-third violation load (> 74 violations) with 133 EPA violations; surface water source; 2,350 served (PWS-level, not municipal population).
- 2,350
- People served (this PWS)
- 133
- EPA violations (this PWS)
- 7
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Colstrip City Of standing, high SDWIS violation third
133 EPA SDWIS violations on record - upper-third violation load (> 74 violations). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 5% is middle-third health share (≤ 23%). Population rank #12,421 of 29,740 among systems serving 500+.
The verdict
Colstrip City Of sits in the upper third of the sitemap cohort by violation count (133), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 2,350 (mid served population (≤ 3,309)). Health-based share is 5% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #12,421 of 29,740
- Population · /systems
- #58 of 283
- Population · MT
- 133
- Total EPA violations on record
- 5%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 913
- County
- Rosebud
- School/Daycare
- No
- MCL Violations
- 3
- Monitoring Violations
- 117
- Treatment Tech Violations
- 4
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| CARBON, TOTAL | MR | 18 | 2004 |
| Coliform (TCR) | MR | 16 | 2008 |
| Surface Water Treatment Rule | MR | 9 | 2024 |
| Arsenic | MR | 6 | 1999 |
| Antimony, Total | MR | 5 | 2003 |
| Selenium | MR | 5 | 2003 |
| Mercury | MR | 5 | 2003 |
| Chromium | MR | 5 | 2003 |
| Cadmium | MR | 5 | 2003 |
| Barium | MR | 5 | 2003 |
| Thallium, Total | MR | 5 | 2003 |
| Beryllium, Total | MR | 5 | 2003 |
| Nickel | MR | 5 | 2003 |
| Surface Water Treatment Rule | TT | 4 | 2024 |
| Lead and Copper Rule | MR | 3 | 2001 |
| Fluoride | MR | 3 | 2003 |
| Revised Total Coliform Rule | MON | 3 | 2022 |
| TTHM | MCL | 3 | 2024 |
| Nitrate-Nitrite | MR | 3 | 2000 |
| Asbestos | MR | 3 | 2011 |
| Total Haloacetic Acids (HAA5) | MR | 3 | 2023 |
| TTHM | MR | 3 | 2023 |
| Nitrate | MR | 2 | 1996 |
Violation Count vs. the National Corpus
Colstrip City Of has 133 recorded EPA violations, 79% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 21% carry more. 5% of this system's own violations are health-based (7 of 133), and it ranks #12,421 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
133 Higher than most more violations than 79% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
SDWIS compliance record for Colstrip City Of
133 violations on record for MT0000180; use EPA SDWIS to confirm return-to-compliance dates and monitoring categories.
Sources: EPA SDWIS
Nationwide peers
133 violations · 2,350 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Colstrip City Of
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Montana compares on the same EPA violation measures. Montana systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.