Clean Water Act discharge permit · NPDES MDG490361
CYPRUS MINES, Baltimore, MD: NPDES MDG490361 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 5Pollutants under a numeric limit
- 4Pollutants with an effluent exceedance
CYPRUS MINES, held by POTTS & CALLAHAN, holds NPDES permit MDG490361, which discharges to Back River. EPA’s file records it issued January 31, 2018 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 | CYPRUS MINES |
|---|---|
| Permittee as filed | POTTS & CALLAHAN |
| NPDES ID | MDG490361 |
| 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 |
| Issued | January 31, 2018 |
| Expiration date | April 30, 2022 |
| Issuing agency | Maryland Department of The Environment |
| Address | Baltimore, MD 21220 |
| Receiving water | BACK River |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Back River-Hawk Cove-Chesapeake Bay (HUC 020600030703) |
| SIC | 1629 – Heavy Construction |
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
- 5Pollutants on file
- 5Under a numeric limit
- 5With a violation of any kind
- 4With 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 |
|---|---|---|---|---|---|
| Solids, total suspended | 2 | 177 | 75 | June 30, 2026 | 302% over the limit |
| Solids, settleable | 1 | 59 | 14 | February 28, 2017 | 999,900% over the limit |
| pH change [range] | 2 | 97 | 9 | August 31, 2023 | |
| pH | 2 | 106 | 4 | June 30, 2026 | |
| Flow, in conduit or thru treatment plant | 2 | 143 | 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 MDG490361.
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
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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 MDG490361 there.
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Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.