Clean Water Act discharge permit · NPDES MT0021458
CITY OF DILLON WWTF, Dillon, MT: NPDES MT0021458 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 16Pollutants under a numeric limit
- 6Pollutants with an effluent exceedance
CITY OF DILLON WWTF, held by CITY OF DILLON, holds NPDES permit MT0021458, which discharges to Beaverhead River. EPA’s file records it issued January 19, 2010 and expiring February 28, 2015. 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 DILLON WWTF |
|---|---|
| Permittee as filed | CITY OF DILLON |
| NPDES ID | MT0021458 |
| 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 | January 19, 2010 |
| Expiration date | February 28, 2015 |
| Issuing agency | MONTANA DEQ |
| Address | Dillon, MT 59725 |
| Receiving water | BEAVERHEAD RIVER |
| Receiving water impaired | 303(D) Listed |
| 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
- 18Pollutants on file
- 16Under a numeric limit
- 6With 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 |
|---|---|---|---|---|---|
| E. coli, MTEC-MF | 6 | 10 | 10 | January 31, 2024 | 694% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 6 | 2 | 2 | January 31, 2024 | 8% over the limit |
| Nitrogen, ammonia total [as N] | 4 | 2 | 2 | March 31, 2015 | 66% over the limit |
| BOD, 5-day, 20 deg. C | 0 | 2 | 2 | May 31, 2001 | 33% over the limit |
| Phosphorus, total [as P] | 4 | 1 | 1 | June 30, 2024 | 18% over the limit |
| Coliform, fecal general | 0 | 1 | 1 | September 30, 2003 | 567% over the limit |
| Solids, total suspended | 6 | 0 | 0 | ||
| Nitrogen, total [as N] | 4 | 0 | 0 | ||
| Solids, total dissolved [TDS] | 4 | 0 | 0 | ||
| Temperature, water deg. centigrade | 2 | 0 | 0 | ||
| Flow rate | 2 | 0 | 0 | ||
| Oxygen, dissolved [DO] | 2 | 0 | 0 | ||
| pH | 2 | 0 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 2 | 0 | 0 | ||
| Nitrite + Nitrate total [as N] | 2 | 0 | 0 | ||
| Oil and grease, hexane extr method | 1 | 0 | 0 | ||
| BOD, carbonaceous, percent removal | 1 | 0 | 0 | ||
| Solids, suspended percent removal | 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
- 0Single-event violations
EPA’s single-event violation file, as loaded, holds no violation for NPDES MT0021458.
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 MT0021458 there.
Nearby on the register
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- Every permit record in Montana, A to Z
Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.