Clean Water Act discharge permit · NPDES MD0021687
UPPER POTOMAC RIVER COMM STP, Westernport, MD: NPDES MD0021687 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 16Pollutants under a numeric limit
- 9Pollutants with an effluent exceedance
UPPER POTOMAC RIVER COMM STP, held by UPPER POTOMAC RIVER COMMISSION, holds NPDES permit MD0021687, which discharges to N Br-Potomac River. EPA’s file records it issued May 1, 2001 and expiring April 30, 2006. 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 | UPPER POTOMAC RIVER COMM STP |
|---|---|
| Permittee as filed | UPPER POTOMAC RIVER COMMISSION |
| NPDES ID | MD0021687 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Not a publicly owned treatment works |
| Issued | May 1, 2001 |
| Expiration date | April 30, 2006 |
| Issuing agency | Maryland Department of the Environment |
| Address | Westernport, MD 21562 |
| Receiving water | N BR-POTOMAC RIVER |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Limestone Run-North Branch Potomac River (HUC 020700020402) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 18Pollutants on file
- 16Under a numeric limit
- 9With a violation of any kind
- 9With 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 |
|---|---|---|---|---|---|
| Nitrogen, total [as N] | 4 | 16 | 16 | July 31, 2026 | 28,750% over the limit |
| BOD, 5-day, 20 deg. C | 4 | 5 | 5 | January 31, 2019 | 200% over the limit |
| Solids, total suspended | 4 | 4 | 4 | June 30, 2020 | 28% over the limit |
| Phosphorus, total [as P] | 4 | 3 | 3 | July 31, 2005 | 87% over the limit |
| Turbidity, lab, NTU | 4 | 2 | 2 | December 31, 2009 | |
| Temperature, water deg. fahrenheit | 1 | 2 | 2 | June 30, 2012 | 6% over the limit |
| Color [PT-CO units] | 6 | 1 | 1 | January 31, 2018 | |
| Color | 0 | 1 | 1 | January 31, 2018 | 94% over the limit |
| pH range excursions, > 60 minutes | 0 | 1 | 1 | October 31, 2019 | 2,147,483,650% over the limit |
| Flow, in conduit or thru treatment plant | 4 | 0 | 0 | ||
| Coliform, fecal general | 3 | 0 | 0 | ||
| pH | 2 | 0 | 0 | ||
| Nitrogen, organic total [as N] | 2 | 0 | 0 | ||
| Nitrogen, ammonia total [as N] | 2 | 0 | 0 | ||
| Nitrite + Nitrate total [as N] | 2 | 0 | 0 | ||
| Oxygen, dissolved [DO] | 1 | 0 | 0 | ||
| 2,3,7,8-Tetrachlorodibenzo-p-dioxin | 1 | 0 | 0 | ||
| Chlorine, total residual | 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 MD0021687.
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 MD0021687 there.
Nearby on the register
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- Every permit record in Westernport, A to Z
- Discharge permits in Maryland
- Every permit record in Maryland, A to Z
Figures from EPA’s ICIS-NPDES download, loaded September 14, 2026.