Clean Water Act discharge permit · NPDES MT0022373
COLSTRIP WWTP, Colstrip, MT: NPDES MT0022373 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 17Pollutants under a numeric limit
- 5Pollutants with an effluent exceedance
COLSTRIP WWTP, held by CITY OF COLSTRIP, holds NPDES permit MT0022373, which discharges to East Fork Armells Creek. EPA’s file records it issued November 10, 2011 and expiring December 31, 2016. The status and dates are as EPA’s permit file stood when Velarion loaded it (October 14, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.
Identity
| Facility as filed | COLSTRIP WWTP |
|---|---|
| Permittee as filed | CITY OF COLSTRIP |
| NPDES ID | MT0022373 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Minor discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | November 10, 2011 |
| Expiration date | December 31, 2016 |
| Issuing agency | MONTANA DEQ |
| Address | Colstrip, MT 59323 |
| Receiving water | EAST FORK ARMELLS CREEK |
| SIC | 4952 – Sewerage Systems |
Cited to the EPA ICIS-NPDES permit file (ECHO download) and EPA’s NAICS/SIC and component files, the same download.
Effluent limits and exceedances
- 31Pollutants on file
- 17Under a numeric limit
- 31With a violation of any kind
- 5With an effluent exceedance
An effluent exceedance is a discharge monitoring report value over the permit’s numeric limit (EPA’s violation code E90). A violation of any kind also counts a report not filed. Each row is EPA’s own count for that pollutant.
| Pollutant or measure | Limits | Violations, any kind | Effluent exceedances | Latest exceedance | Largest exceedance, as filed |
|---|---|---|---|---|---|
| Nitrogen, total [as N] | 2 | 33 | 22 | September 30, 2011 | 389% over the limit |
| Flow rate | 2 | 18 | 5 | September 30, 2007 | 49% over the limit |
| BOD, 5-day, percent removal | 2 | 11 | 1 | June 30, 1997 | 33% over the limit |
| Solids, suspended percent removal | 2 | 11 | 1 | June 30, 1997 | 47% over the limit |
| Chlorine, total residual | 0 | 2 | 1 | December 31, 2006 | 16% over the limit |
| BOD, 5-day, 20 deg. C | 8 | 43 | 0 | ||
| Solids, total suspended | 8 | 42 | 0 | ||
| Nitrogen, ammonia total [as N] | 5 | 15 | 0 | ||
| pH | 2 | 14 | 0 | ||
| Phosphorus, total [as P] | 2 | 11 | 0 | ||
| Nitrite + Nitrate total [as N] | 4 | 10 | 0 | ||
| Temperature, water deg. centigrade | 2 | 10 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 2 | 10 | 0 | ||
| E. coli | 4 | 8 | 0 | ||
| Coliform, fecal general | 0 | 3 | 0 | ||
| Report due [yrmoda] | 1 | 2 | 0 | ||
| Pass/Fail Static 48Hr Acute Ceriodaphnia dubia | 1 | 2 | 0 | ||
| Pass/Fail Static Renewal 96Hr Acute Pimephales Promelas | 1 | 2 | 0 | ||
| Hardness, total [as CaCO3] | 0 | 2 | 0 | ||
| Arsenic, total recoverable | 0 | 2 | 0 | ||
| Selenium, total recoverable | 0 | 2 | 0 | ||
| Silver total recoverable | 0 | 2 | 0 | ||
| Zinc, total recoverable | 0 | 2 | 0 | ||
| Cadmium, total recoverable | 0 | 2 | 0 | ||
| Lead, total recoverable | 0 | 2 | 0 | ||
| Chromium, total recoverable | 0 | 2 | 0 | ||
| Copper, total recoverable | 0 | 2 | 0 | ||
| E. coli, MTEC-MF | 0 | 2 | 0 | ||
| Mercury, total recoverable | 0 | 2 | 0 | ||
| Oil and grease, hexane extr method | 1 | 1 | 0 | ||
| Chloride [as Cl] | 0 | 1 | 0 |
Cited to the EPA ICIS-NPDES limits and effluent violations files (ECHO download); up to 60 rows shown, most exceedances first.
Inspections, violations and enforcement
- 3Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| February 22, 2024 | WW Storm Water Non-Construction - Failure to Maintain Records | ST6 |
| October 28, 2020 | Reporting Violations - Failure to submit required report (non-DMR non-pretreatment) | ST6 |
| October 28, 2020 | Monitoring Violations - Improper Analysis or Lab Error | ST6 |
Velarion’s copy of EPA’s ICIS-NPDES files does not include the inspections, formal enforcement actions and informal enforcement actions files, so this page shows none of them. EPA’s free Detailed Facility Report on ECHO lists this permit’s inspections, enforcement actions and penalties.
Cited to the EPA ICIS-NPDES violation, inspection and enforcement files (ECHO download); up to 50 rows of each shown, newest first.
Watch this permit
One permit holder, $99/month. Watch the register for one permit holder and the places and receiving waters tied to its permits. Choose “One permit holder” and enter this permit’s NPDES ID, MT0022373.
Start the watch
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EPA publishes a free Detailed Facility Report for every permit on ECHO: its compliance status quarter by quarter, its inspections, and its enforcement actions and penalties. EPA also sends free notices of new inspections and enforcement actions through ECHO Notify; enter NPDES ID MT0022373 there.
Nearby on the register
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- Every permit record in Colstrip, A to Z
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- Every permit record in Montana, A to Z
Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.