Clean Water Act discharge permit · NPDES SC0040771
MT PLEASANT CENTER ST & HENRY CLAY DUFFIE WRF, Mount Pleasant, SC: NPDES SC0040771 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MajorDischarger class
- 16Pollutants under a numeric limit
- 8Pollutants with an effluent exceedance
MT PLEASANT CENTER ST & HENRY CLAY DUFFIE WRF, held by MOUNT PLEASANT WATERWORKS, holds NPDES permit SC0040771. EPA’s file records it issued July 10, 2025 and expiring April 30, 2030. The status and dates are as EPA’s permit file stood when Velarion loaded it (September 14, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.
Identity
| Facility as filed | MT PLEASANT CENTER ST & HENRY CLAY DUFFIE WRF |
|---|---|
| Permittee as filed | MOUNT PLEASANT WATERWORKS |
| NPDES ID | SC0040771 |
| Permit status | Effective |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | July 10, 2025 |
| Expiration date | April 30, 2030 |
| Issuing agency | State |
| Address | Mount Pleasant, SC 29464 |
| Subwatershed | Lower Cooper River (HUC 030502010707) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 18Pollutants on file
- 16Under a numeric limit
- 15With a violation of any kind
- 8With 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 |
|---|---|---|---|---|---|
| Coliform, fecal general | 0 | 20 | 16 | October 31, 2008 | 300% over the limit |
| Chlorine, total residual | 8 | 20 | 14 | November 30, 2015 | 240% over the limit |
| Flow, in conduit or thru treatment plant | 8 | 22 | 3 | August 31, 2013 | 10% over the limit |
| pH | 8 | 37 | 2 | August 31, 2009 | |
| Nitrogen, ammonia total [as N] | 16 | 16 | 2 | May 31, 2007 | 5% over the limit |
| % Effect Static Renewal 7 Day Chronic Americamysis bahia (formerly Mysidopsis bahia) | 4 | 4 | 2 | September 30, 2009 | 33% over the limit |
| Solids, total suspended | 16 | 13 | 1 | April 30, 2006 | 167% over the limit |
| Solids, suspended percent removal | 2 | 3 | 1 | March 31, 2013 | 13% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 8 | 14 | 0 | ||
| Nitrogen, total [as N] | 8 | 8 | 0 | ||
| Phosphorus, total [as P] | 8 | 8 | 0 | ||
| Oxygen, dissolved [DO] | 2 | 3 | 0 | ||
| Oxygen demand, ultimate | 4 | 2 | 0 | ||
| Carbonaceous oxygen demand, % removal | 2 | 2 | 0 | ||
| Pass/Fail Static 48Hr Acute Americamysis bahia (formerly Mysidopsis bahia) | 0 | 2 | 0 | ||
| Enterococci | 8 | 0 | 0 | ||
| LC50 Static 48Hr Acute Americamysis bahia (formerly Mysidopsis bahia) | 2 | 0 | 0 | ||
| IC25 Static Renewal 7 Day Chronic Americamysis bahia (formerly Mysidopsis bahia) | 2 | 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 SC0040771.
Velarion’s copy of EPA’s ICIS-NPDES files does not yet 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 SC0040771 there.
Nearby on the register
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- Every permit record in Mount Pleasant, A to Z
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- Every permit record in South Carolina, A to Z
Figures from EPA’s ICIS-NPDES download, loaded September 14, 2026.