Clean Water Act discharge permit · NPDES MT0020494
LIBBY WWTP, Libby, MT: NPDES MT0020494 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 21Pollutants under a numeric limit
- 3Pollutants with an effluent exceedance
LIBBY WWTP, held by CITY OF LIBBY, holds NPDES permit MT0020494, which discharges to Kootenai River. EPA’s file records it issued July 27, 2009 and expiring August 31, 2014. 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 | LIBBY WWTP |
|---|---|
| Permittee as filed | CITY OF LIBBY |
| NPDES ID | MT0020494 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | July 27, 2009 |
| Expiration date | August 31, 2014 |
| Issuing agency | MONTANA DEQ |
| Address | Libby, MT 59923 |
| Receiving water | KOOTENAI RIVER |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Middle Kootenai River (HUC 170101011005) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 26Pollutants on file
- 21Under a numeric limit
- 22With a violation of any kind
- 3With 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 |
|---|---|---|---|---|---|
| pH | 3 | 15 | 5 | October 31, 2024 | |
| Solids, total suspended | 5 | 18 | 4 | August 31, 2021 | 555% over the limit |
| Solids, suspended percent removal | 1 | 6 | 2 | November 30, 2024 | 140% over the limit |
| BOD, 5-day, 20 deg. C | 5 | 16 | 0 | ||
| Nitrogen, ammonia total [as N] | 2 | 10 | 0 | ||
| E. coli, MTEC-MF | 6 | 8 | 0 | ||
| Flow rate | 4 | 8 | 0 | ||
| Phosphorus, total [as P] | 2 | 7 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 1 | 7 | 0 | ||
| Nitrite + Nitrate total [as N] | 1 | 7 | 0 | ||
| Nitrogen, total [as N] | 2 | 6 | 0 | ||
| Temperature, water deg. fahrenheit | 0 | 6 | 0 | ||
| Chlorine, total residual | 1 | 5 | 0 | ||
| Coliform, fecal general | 0 | 5 | 0 | ||
| Oil and grease, hexane extr method | 1 | 4 | 0 | ||
| BOD, 5-day, percent removal | 1 | 4 | 0 | ||
| Zinc, total recoverable | 1 | 3 | 0 | ||
| Copper, total recoverable | 1 | 3 | 0 | ||
| Hardness, total [as CaCO3] | 1 | 2 | 0 | ||
| Flow, in conduit or thru treatment plant | 0 | 2 | 0 | ||
| Pass/Fail Static 48Hr Acute Ceriodaphnia dubia | 0 | 2 | 0 | ||
| Pass/Fail Static 96 Hr Acute Pimephales Promelas | 0 | 2 | 0 | ||
| Temperature, water deg. centigrade | 2 | 0 | 0 | ||
| Oxygen, dissolved [DO] | 1 | 0 | 0 | ||
| Pass/Fail Static Renewal 48Hr Acute Ceriodaphnia dubia | 1 | 0 | 0 | ||
| Pass/Fail Static Renewal 96Hr Acute Pimephales Promelas | 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
- 13Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| December 10, 2025 | Monitoring Violations - Invalid/Unrepresentative Sample | ST6 |
| December 10, 2025 | Effluent Violations - Numeric effluent violation | ST6 |
| December 10, 2025 | Reporting Violations - Late Submittal of DMRs | ST6 |
| December 10, 2025 | Reporting Violations - Failure to Notify | ST6 |
| December 10, 2025 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| December 10, 2025 | Monitoring Violations - Improper Analysis or Lab Error | ST6 |
| December 6, 2023 | Monitoring Violations - Improper Analysis or Lab Error | ST6 |
| December 6, 2023 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| December 6, 2023 | Monitoring Violations - Analysis not Conducted | ST6 |
| February 16, 2022 | Monitoring Violations - Improper Analysis or Lab Error | ST6 |
| February 16, 2022 | Management Practice Violations - Failure to Maintain Records | ST6 |
| February 16, 2022 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| February 16, 2022 | Monitoring Violations - Frequency of Sampling Violation | 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, MT0020494.
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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 MT0020494 there.
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Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.