Clean Water Act discharge permit · NPDES MT0031488
CITY OF SHELBY WASTEWATER LAGOONS, Shelby, MT: NPDES MT0031488 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 10Pollutants under a numeric limit
- 6Pollutants with an effluent exceedance
CITY OF SHELBY WASTEWATER LAGOONS, held by CITY OF SHELBY, holds NPDES permit MT0031488, which discharges to Medicine Rock Coulee. EPA’s file records it issued March 21, 2014 and expiring April 30, 2019. The status and dates are as EPA’s permit file stood when Velarion loaded it (September 15, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.
Identity
| Facility as filed | CITY OF SHELBY WASTEWATER LAGOONS |
|---|---|
| Permittee as filed | CITY OF SHELBY |
| NPDES ID | MT0031488 |
| 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 | March 21, 2014 |
| Expiration date | April 30, 2019 |
| Address | Shelby, MT 59474 |
| Receiving water | MEDICINE ROCK COULEE |
| Subwatershed | Marias River-Shelby (HUC 100302030802) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 21Pollutants on file
- 10Under a numeric limit
- 20With a violation of any kind
- 6With 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 |
|---|---|---|---|---|---|
| Solids, total suspended | 5 | 63 | 61 | May 31, 2026 | 200% over the limit |
| BOD, 5-day, 20 deg. C | 5 | 47 | 45 | January 31, 2025 | 99,999% over the limit |
| BOD, 5-day, percent removal | 1 | 16 | 15 | May 31, 2026 | 371% over the limit |
| E. coli, MTEC-MF | 4 | 15 | 13 | July 31, 2022 | 463% over the limit |
| Solids, suspended percent removal | 1 | 12 | 10 | May 31, 2026 | 195% over the limit |
| Pass/Fail Static Renewal 96Hr Acute Pimephales Promelas | 0 | 2 | 1 | June 30, 2012 | |
| Phosphorus, total [as P] | 0 | 8 | 0 | ||
| Nitrogen, total [as N] | 0 | 6 | 0 | ||
| Solids, total dissolved [TDS] | 0 | 5 | 0 | ||
| Temperature, water deg. centigrade | 0 | 4 | 0 | ||
| Nitrogen, ammonia total [as N] | 0 | 4 | 0 | ||
| Oil & Grease | 1 | 3 | 0 | ||
| Oxygen, dissolved [DO] | 0 | 3 | 0 | ||
| Oil and grease, hexane extr method | 0 | 3 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 0 | 3 | 0 | ||
| Nitrite + Nitrate total [as N] | 0 | 3 | 0 | ||
| pH | 2 | 2 | 0 | ||
| Duration of discharge | 1 | 2 | 0 | ||
| Oil and grease visual | 1 | 1 | 0 | ||
| Pass/Fail Static Renewal 48Hr Acute Ceriodaphnia dubia | 0 | 1 | 0 | ||
| Flow rate | 2 | 0 | 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
- 13Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| February 11, 2026 | Monitoring Violations - Invalid/Unrepresentative Sample | ST6 |
| February 11, 2026 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| February 11, 2026 | Monitoring Violations - Analysis not Conducted | ST6 |
| February 11, 2026 | Monitoring Violations - Frequency of Sampling Violation | ST6 |
| February 11, 2026 | Management Practice Violations - Failure to Maintain Records | ST6 |
| February 11, 2026 | Management Practice Violations - Failure to Conduct Inspections | ST6 |
| January 27, 2021 | Monitoring Violations - Invalid/Unrepresentative Sample | ST6 |
| January 27, 2021 | Monitoring Violations - Frequency of Sampling Violation | ST6 |
| January 27, 2021 | Management Practice Violations - Improper Operation and Maintenance | ST6 |
| January 27, 2021 | Effluent Violations - Unapproved Bypass | ST6 |
| January 27, 2021 | Monitoring Violations - Analysis not Conducted | ST6 |
| January 27, 2021 | Management Practice Violations - Failure to Maintain Records | ST6 |
| January 27, 2021 | Reporting Violations - Improper/ Incorrect Reporting | 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.
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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 MT0031488 there.
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Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.