Clean Water Act discharge permit · NPDES DE0000558
CALPINE MID-ATLANTIC, Wilmington, DE: NPDES DE0000558 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 21Pollutants under a numeric limit
- 4Pollutants with an effluent exceedance
CALPINE MID-ATLANTIC, held by Calpine Mid-Atlantic, holds NPDES permit DE0000558. EPA’s file records it issued November 1, 1998 and expiring October 31, 2003. The status and dates are as EPA’s permit file stood when Velarion loaded it (September 15, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.
Identity
| Facility as filed | CALPINE MID-ATLANTIC |
|---|---|
| Permittee as filed | Calpine Mid-Atlantic |
| NPDES ID | DE0000558 |
| 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 | November 1, 1998 |
| Expiration date | October 31, 2003 |
| Address | Wilmington, DE 19809 |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Matson Run-Shellpot Creek (HUC 020402050602) |
| Other EPA IDs (FRS) | RCRA handler DED000621417; ICIS-AIR source DE0000001000300007 |
Cited to the EPA ICIS-NPDES permit file (ECHO download); cross-program IDs from EPA’s FRS facility-registry crosswalk.
Effluent limits and exceedances
- 21Pollutants on file
- 21Under a numeric limit
- 7With 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 | 14 | 14 | 6 | February 28, 2018 | 74% over the limit |
| Temperature, water deg. fahrenheit | 4 | 3 | 3 | August 31, 2016 | 4% over the limit |
| Chlorine, free available | 2 | 3 | 3 | February 29, 2020 | 95% over the limit |
| pH | 7 | 5 | 1 | May 31, 1999 | |
| Chlorination | 1 | 63 | 0 | ||
| Oil & Grease | 12 | 8 | 0 | ||
| Thermal Discharge | 4 | 8 | 0 | ||
| Flow, in conduit or thru treatment plant | 9 | 0 | 0 | ||
| Copper, total [as Cu] | 8 | 0 | 0 | ||
| Hardness, total [as CaCO3] | 4 | 0 | 0 | ||
| Cadmium, total [as Cd] | 4 | 0 | 0 | ||
| Iron, total [as Fe] | 4 | 0 | 0 | ||
| Lead, total [as Pb] | 4 | 0 | 0 | ||
| Zinc, total [as Zn] | 4 | 0 | 0 | ||
| BOD, 5-day, 20 deg. C | 2 | 0 | 0 | ||
| Biomass, plankton | 2 | 0 | 0 | ||
| Nitrogen, ammonia total [as N] | 2 | 0 | 0 | ||
| Nitrogen, nitrate total [as N] | 2 | 0 | 0 | ||
| Phosphorus, total [as P] | 2 | 0 | 0 | ||
| Enterococci: group D, MF trans, M-E, EIA | 1 | 0 | 0 | ||
| Pump hours | 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
- 1Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| June 16, 2025 | Effluent Violations - Industrial Spill | 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.
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 DE0000558 there.
Nearby on the register
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- Every permit record in Wilmington, A to Z
- Discharge permits in Delaware
- Every permit record in Delaware, A to Z
Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.