Clean Water Act discharge permit · NPDES MT0020354
CITY OF HARLOWTON WWTF, Harlowton, MT: NPDES MT0020354 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 21Pollutants under a numeric limit
- 6Pollutants with an effluent exceedance
CITY OF HARLOWTON WWTF, held by CITY OF HARLOWTON, holds NPDES permit MT0020354, which discharges to Musselshell River. EPA’s file records it issued July 14, 2017 and expiring August 31, 2022. 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 | CITY OF HARLOWTON WWTF |
|---|---|
| Permittee as filed | CITY OF HARLOWTON |
| NPDES ID | MT0020354 |
| 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 | July 14, 2017 |
| Expiration date | August 31, 2022 |
| Address | Harlowton, MT 59036 |
| Receiving water | MUSSELSHELL RIVER |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Musselshell River-Harlowton (HUC 100402011003) |
| 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
- 26Pollutants on file
- 21Under 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 |
|---|---|---|---|---|---|
| BOD, 5-day, 20 deg. C | 9 | 64 | 52 | July 31, 2026 | 733,233% over the limit |
| E. coli, MTEC-MF | 8 | 38 | 34 | July 31, 2021 | 1,945% over the limit |
| Solids, total suspended | 10 | 42 | 24 | July 31, 2026 | 127% over the limit |
| BOD, 5-day, percent removal | 2 | 16 | 15 | June 30, 2011 | 923% over the limit |
| Chlorine, total residual | 2 | 20 | 13 | January 31, 2020 | 190% over the limit |
| pH | 4 | 14 | 10 | November 30, 2024 | |
| Salinity | 0 | 8 | 0 | ||
| Chloride [as Cl] | 0 | 8 | 0 | ||
| Solids, total dissolved | 0 | 8 | 0 | ||
| Nitrogen, ammonia total [as N] | 1 | 4 | 0 | ||
| Nitrite + Nitrate total [as N] | 1 | 4 | 0 | ||
| Flow rate | 2 | 3 | 0 | ||
| Phosphorus, total [as P] | 2 | 3 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 1 | 3 | 0 | ||
| Solids, suspended percent removal | 1 | 3 | 0 | ||
| Nitrogen, total [as N] | 2 | 2 | 0 | ||
| Oxygen, dissolved [DO] | 1 | 2 | 0 | ||
| Flow rate | 0 | 2 | 0 | ||
| Temperature, water deg. fahrenheit | 1 | 1 | 0 | ||
| Coliform, fecal general | 0 | 1 | 0 | ||
| Selenium, total recoverable | 2 | 0 | 0 | ||
| Cadmium, total recoverable | 2 | 0 | 0 | ||
| Lead, total recoverable | 2 | 0 | 0 | ||
| Copper, total recoverable | 2 | 0 | 0 | ||
| Mercury, total recoverable | 2 | 0 | 0 | ||
| Oil and grease, hexane extr method | 1 | 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
- 5Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| December 18, 2025 | Management Practice Violations - Failure to Maintain Records | ST6 |
| December 18, 2025 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| March 22, 2021 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| March 22, 2021 | Monitoring Violations - Analysis not Conducted | ST6 |
| March 22, 2021 | Management Practice Violations - Failure to Maintain Records | 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
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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 MT0020354 there.
Nearby on the register
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Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.