Clean Water Act discharge permit · NPDES PA0004278
DUQUESNE SLAG, West Mifflin, PA: NPDES PA0004278 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MinorDischarger class
- 19Pollutants under a numeric limit
- 5Pollutants with an effluent exceedance
DUQUESNE SLAG, held by HOLCIM QUARRIES NY INC, holds NPDES permit PA0004278, which discharges to Thompson Run. EPA’s file records it issued June 4, 2024 and expiring June 30, 2029. 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 | DUQUESNE SLAG |
|---|---|
| Permittee as filed | HOLCIM QUARRIES NY INC |
| NPDES ID | PA0004278 |
| Permit status | Effective |
| Permit type | Individual permit |
| Discharger class | Minor discharger |
| Facility type | Not a publicly owned treatment works |
| Issued | June 4, 2024 |
| Expiration date | June 30, 2029 |
| Issuing agency | State Environmental Organization |
| Address | West Mifflin, PA 15122 |
| Receiving water | Thompson Run |
| Subwatershed | Streets Run-Monongahela River (HUC 050200050808) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 19Pollutants on file
- 19Under a numeric limit
- 15With a violation of any kind
- 5With 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 |
|---|---|---|---|---|---|
| Iron, total [as Fe] | 7 | 73 | 60 | September 30, 2024 | 367% over the limit |
| Manganese, total [as Mn] | 6 | 24 | 12 | September 30, 2024 | 660% over the limit |
| Solids, total suspended | 7 | 21 | 8 | May 31, 1990 | 192% over the limit |
| pH | 7 | 16 | 3 | July 31, 2022 | |
| Nickel, total [as Ni] | 6 | 15 | 3 | September 30, 2024 | 304% over the limit |
| Flow, in conduit or thru treatment plant | 6 | 16 | 0 | ||
| Aluminum, total [as Al] | 7 | 13 | 0 | ||
| Iron, dissolved [as Fe] | 2 | 6 | 0 | ||
| Boron, total [as B] | 2 | 4 | 0 | ||
| Chromium, trivalent [as Cr] | 2 | 4 | 0 | ||
| Cobalt, total [as Co] | 2 | 4 | 0 | ||
| Copper, total [as Cu] | 2 | 4 | 0 | ||
| Zinc, total [as Zn] | 2 | 4 | 0 | ||
| Selenium, total [as Se] | 2 | 4 | 0 | ||
| Oil & Grease | 1 | 1 | 0 | ||
| Perfluorooctanoic acid (PFOA) | 1 | 0 | 0 | ||
| Perfluorooctanesulfonate | 1 | 0 | 0 | ||
| Perfluorobutanesulfonic acid (PFBS) | 1 | 0 | 0 | ||
| Hexafluoropropylene oxide dimer acid (HFPO-DA) | 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
- 2Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| March 4, 2025 | Permit Violations - Failure to Pay Fees | ST6 |
| December 16, 2019 | Effluent Violations - Numeric effluent violation | 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 PA0004278 there.
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Figures from EPA’s ICIS-NPDES download, loaded September 14, 2026.