Clean Water Act discharge permit · NPDES MO0022381
MOUNT VERNON WWTP, Mount Vernon, MO: NPDES MO0022381 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MajorDischarger class
- 18Pollutants under a numeric limit
- 10Pollutants with an effluent exceedance
MOUNT VERNON WWTP, held by City of Mount Vernon, holds NPDES permit MO0022381, which discharges to Williams Cr.. EPA’s file records it issued December 11, 2019 and expiring March 31, 2023. 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 | MOUNT VERNON WWTP |
|---|---|
| Permittee as filed | City of Mount Vernon |
| NPDES ID | MO0022381 |
| Permit status | Effective |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | December 11, 2019 |
| Expiration date | March 31, 2023 |
| Address | Mount Vernon, MO 65712 |
| Receiving water | Williams Cr. |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Williams Creek (HUC 110702070105) |
| Program components on file | POTW, Pretreatment |
| 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
- 18Under a numeric limit
- 24With a violation of any kind
- 10With 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 |
|---|---|---|---|---|---|
| Chlorine, total residual | 0 | 102 | 26 | October 31, 2009 | 9,900% over the limit |
| Nitrogen, ammonia total [as N] | 8 | 38 | 12 | February 28, 2025 | 482% over the limit |
| BOD, 5-day, 20 deg. C | 2 | 51 | 11 | June 30, 2017 | 166% over the limit |
| Cadmium, total recoverable | 2 | 88 | 8 | December 31, 2021 | 1,983% over the limit |
| Coliform, fecal general | 0 | 15 | 7 | September 30, 2014 | 5,880% over the limit |
| Oil and grease [soxhlet extr.] tot. | 2 | 30 | 6 | March 31, 2025 | 60% over the limit |
| E. coli | 2 | 20 | 6 | May 31, 2024 | 1,532% over the limit |
| Ammonia [as N] + unionized ammonia | 0 | 18 | 4 | March 31, 2017 | 121% over the limit |
| Solids, total suspended | 2 | 43 | 3 | April 30, 2017 | 24% over the limit |
| pH | 2 | 47 | 2 | February 28, 2019 | |
| Nickel, total recoverable | 2 | 84 | 0 | ||
| Zinc, total recoverable | 2 | 80 | 0 | ||
| Copper, total recoverable | 2 | 80 | 0 | ||
| Flow, in conduit or thru treatment plant | 2 | 30 | 0 | ||
| Phosphorus, total [as P] | 6 | 16 | 0 | ||
| Nitrogen, total [as N] | 0 | 16 | 0 | ||
| BOD, 5-day, percent removal | 1 | 11 | 0 | ||
| Solids, suspended percent removal | 1 | 11 | 0 | ||
| Hardness, total [as CaCO3] | 2 | 10 | 0 | ||
| Iron, total recoverable | 2 | 10 | 0 | ||
| Toxicity [chronic], Ceriodaphnia dubia | 0 | 2 | 0 | ||
| Toxicity [chronic], Pimephales promelas [Fathead Minnow] | 0 | 2 | 0 | ||
| Toxicity [acute], Ceriodaphnia dubia | 0 | 1 | 0 | ||
| Toxicity [acute], Pimephales promelas [Fathead Minnow] | 0 | 1 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 6 | 0 | 0 | ||
| Nitrite + Nitrate total [as N] | 6 | 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
- 16Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| December 30, 2021 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| December 30, 2021 | Permit Violations - Violation Specified in Comment | ST6 |
| December 30, 2021 | Effluent Violations - Numeric effluent violation | ST6 |
| January 14, 2020 | Management Practice Violations - Improper Operation and Maintenance | ST6 |
| January 14, 2020 | Effluent Violations - Numeric effluent violation | ST6 |
| May 2, 2019 | Reporting Violations - Failure to submit required report (non-DMR non-pretreatment) | ST6 |
| May 2, 2019 | Reporting Violations - Improper/ Incorrect Reporting | ST6 |
| May 2, 2019 | Effluent Violations - Numeric effluent violation | ST6 |
| May 2, 2019 | Permit Violations - Violation Specified in Comment | ST6 |
| May 2, 2019 | WW SSO - Failure to report violation that may endanger public health 122.41(l)(7) | ST6 |
| May 2, 2019 | WW Storm Water Construction - Failure to develop any or adequate SWPPP/SWMP | ST6 |
| May 2, 2019 | Management Practice Violations - Improper Operation and Maintenance | ST6 |
| May 24, 2018 | Pretreatment - Failure to Develop/Enforce Standards | ST6 |
| September 20, 2017 | Management Practice Violations - Improper Operation and Maintenance | ST6 |
| September 20, 2017 | Permit Violations - Violation Specified in Comment | ST6 |
| June 14, 2017 | Pretreatment - Failure to Develop/Enforce Standards | 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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Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.