Clean Water Act discharge permit · NPDES MT0030732
ENNIS WWTP, Ennis, MT: NPDES MT0030732 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 29Pollutants under a numeric limit
- 5Pollutants with an effluent exceedance
ENNIS WWTP, held by TOWN OF ENNIS, holds NPDES permit MT0030732, which discharges to Madison River. EPA’s file records it issued April 20, 2006 and expiring October 31, 2011. 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 | ENNIS WWTP |
|---|---|
| Permittee as filed | TOWN OF ENNIS |
| NPDES ID | MT0030732 |
| 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 | April 20, 2006 |
| Expiration date | October 31, 2011 |
| Issuing agency | MONTANA DEQ |
| Address | Ennis, MT 59729 |
| Receiving water | MADISON RIVER |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Madison River-Lower O'Dell Creek (HUC 100200071205) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 29Pollutants on file
- 29Under a numeric limit
- 18With 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 |
|---|---|---|---|---|---|
| Solids, total suspended | 4 | 54 | 50 | April 30, 2025 | 211% over the limit |
| BOD, 5-day, 20 deg. C | 4 | 25 | 20 | May 31, 2026 | 133% over the limit |
| Solids, suspended percent removal | 1 | 21 | 20 | May 31, 2018 | 253% over the limit |
| BOD, 5-day, percent removal | 1 | 6 | 5 | July 31, 2019 | 60% over the limit |
| pH | 2 | 5 | 2 | January 31, 2019 | |
| Nitrogen, total [as N] | 2 | 6 | 0 | ||
| Phosphorus, total [as P] | 2 | 6 | 0 | ||
| Nitrogen, ammonia total [as N] | 3 | 5 | 0 | ||
| Chlorine, total residual | 2 | 4 | 0 | ||
| Oxygen, dissolved [DO] | 1 | 3 | 0 | ||
| Flow rate | 2 | 2 | 0 | ||
| Arsenic, total recoverable | 1 | 2 | 0 | ||
| Zinc, total recoverable | 1 | 2 | 0 | ||
| Coliform, fecal general | 1 | 2 | 0 | ||
| Temperature, water deg. centigrade | 1 | 1 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 1 | 1 | 0 | ||
| Nitrite + Nitrate total [as N] | 1 | 1 | 0 | ||
| Copper, total recoverable | 1 | 1 | 0 | ||
| Oil and grease, hexane extr method | 1 | 0 | 0 | ||
| Hardness, total [as CaCO3] | 1 | 0 | 0 | ||
| Selenium, total recoverable | 1 | 0 | 0 | ||
| Silver total recoverable | 1 | 0 | 0 | ||
| Cadmium, total recoverable | 1 | 0 | 0 | ||
| Lead, total recoverable | 1 | 0 | 0 | ||
| Chromium, total recoverable | 1 | 0 | 0 | ||
| Petrol hydrocarbons, total recoverable | 1 | 0 | 0 | ||
| Phenols | 1 | 0 | 0 | ||
| Solids, total dissolved [TDS] | 1 | 0 | 0 | ||
| Mercury, total recoverable | 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 |
|---|---|---|
| January 10, 2022 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| January 11, 2017 | Monitoring Violations - No Flow Measurement Device | ST6 |
| January 11, 2017 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| January 11, 2017 | Monitoring Violations - Improper Analysis or Lab Error | ST6 |
| January 11, 2017 | 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 MT0030732 there.
Nearby on the register
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Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.