Clean Water Act discharge permit · NPDES MOG490671
SEMO OPERATING COMPANY, Dexter, MO: NPDES MOG490671 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 0Pollutants under a numeric limit
- 1Pollutants with an effluent exceedance
SEMO OPERATING COMPANY, held by SEMO Operating Company LLC, holds NPDES permit MOG490671, which discharges to Tributary To Dudley Main Ditch. EPA’s file records it issued May 1, 2017 and expiring April 30, 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 | SEMO OPERATING COMPANY |
|---|---|
| Permittee as filed | SEMO Operating Company LLC |
| NPDES ID | MOG490671 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Coverage under a general permit |
| Discharger class | Minor discharger |
| Facility type | Not a publicly owned treatment works |
| Program | Industrial stormwater |
| Issued | May 1, 2017 |
| Expiration date | April 30, 2022 |
| Address | Dexter, MO 63801 |
| Receiving water | Tributary to Dudley Main Ditch |
| Subwatershed | Lick Creek Ditch (HUC 080202030202) |
| SIC | 3273 – Ready-Mixed Concrete |
| Other EPA IDs (FRS) | ICIS-AIR source MO0000002920700063 |
Cited to the EPA ICIS-NPDES permit file (ECHO download) and EPA’s NAICS/SIC and component files, the same download; cross-program IDs from EPA’s FRS facility-registry crosswalk.
Effluent limits and exceedances
- 5Pollutants on file
- 0Under a numeric limit
- 5With a violation of any kind
- 1With 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 | 0 | 13 | 1 | September 30, 2008 | |
| Solids, settleable | 0 | 12 | 0 | ||
| Oil and grease [soxhlet extr.] tot. | 0 | 12 | 0 | ||
| Solids, total suspended | 0 | 10 | 0 | ||
| Flow, in conduit or thru treatment plant | 0 | 10 | 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
- 1Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| January 27, 2021 | WW Storm Water Construction - Failure to develop any or adequate SWPPP/SWMP | 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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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 MOG490671 there.
Nearby on the register
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- Every permit record in Dexter, A to Z
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- Every permit record in Missouri, A to Z
Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.