Clean Water Act discharge permit · NPDES MN0055301
NORTHSHORE MINING CO - SILVER BAY, Silver Bay, MN: NPDES MN0055301 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MajorDischarger class
- 50Pollutants under a numeric limit
- 3Pollutants with an effluent exceedance
NORTHSHORE MINING CO - SILVER BAY, held by Northshore Mining Co, holds NPDES permit MN0055301. EPA’s file records it issued September 1, 2025 and expiring July 31, 2030. 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 | NORTHSHORE MINING CO - SILVER BAY |
|---|---|
| Permittee as filed | Northshore Mining Co |
| NPDES ID | MN0055301 |
| Permit status | Effective |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Not a publicly owned treatment works |
| Issued | September 1, 2025 |
| Expiration date | July 31, 2030 |
| Issuing agency | STA |
| Address | Silver Bay, MN 55614 |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | City of Silver Bay-Frontal Lake Superior (HUC 040101020101) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 52Pollutants on file
- 50Under a numeric limit
- 11With a violation of any kind
- 3With 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 |
|---|---|---|---|---|---|
| Fluoride, total [as F] | 8 | 107 | 8 | August 31, 2015 | 46% over the limit |
| Asbestos, total amphibole | 5 | 5 | 3 | January 31, 2020 | 91% over the limit |
| Waste heat rejection rate | 0 | 1 | 1 | August 31, 2010 | 41% over the limit |
| Turbidity | 9 | 152 | 0 | ||
| Temp. diff. between samp. & upstrm deg. C | 0 | 94 | 0 | ||
| Diesel range organics diesel, total, wtr | 1 | 26 | 0 | ||
| Fibers, ambiguous asbestos | 5 | 4 | 0 | ||
| Fibers, non-amphibole, non-chrysotile asbestos | 5 | 4 | 0 | ||
| Flow, in conduit or thru treatment plant | 18 | 2 | 0 | ||
| Asbestos, Chrysotile | 5 | 2 | 0 | ||
| Asbestos | 5 | 1 | 0 | ||
| pH | 16 | 0 | 0 | ||
| Iron, total [as Fe] | 8 | 0 | 0 | ||
| Specific conductance | 7 | 0 | 0 | ||
| Solids, total suspended | 7 | 0 | 0 | ||
| Calcium, total [as Ca] | 7 | 0 | 0 | ||
| Magnesium, total [as Mg] | 7 | 0 | 0 | ||
| Sodium, total [as Na] | 7 | 0 | 0 | ||
| Potassium, total [as K] | 7 | 0 | 0 | ||
| Chloride [as Cl] | 7 | 0 | 0 | ||
| Sulfate, total [as SO4] | 7 | 0 | 0 | ||
| Manganese, total [as Mn] | 7 | 0 | 0 | ||
| Solids, total dissolved | 7 | 0 | 0 | ||
| Alkalinity, total [as CaCO3] | 6 | 0 | 0 | ||
| Temperature, water deg. centigrade | 4 | 0 | 0 | ||
| Stream flow, instantaneous | 4 | 0 | 0 | ||
| Nitrogen, nitrate total [as N] | 4 | 0 | 0 | ||
| Hardness, total [as CaCO3] | 4 | 0 | 0 | ||
| Iron, dissolved [as Fe] | 4 | 0 | 0 | ||
| Nitrite + Nitrate total [as N] | 3 | 0 | 0 | ||
| Sodium, % total cations | 3 | 0 | 0 | ||
| Redox [oxidation reduction potential] | 2 | 0 | 0 | ||
| Nitrogen, total [as N] | 2 | 0 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 2 | 0 | 0 | ||
| Copper, total [as Cu] | 2 | 0 | 0 | ||
| Molybdenum, total [as Mo] | 2 | 0 | 0 | ||
| Precipitation, total defined period/in | 1 | 0 | 0 | ||
| Evaporation, Accumulated | 1 | 0 | 0 | ||
| Bicarbonate ion- [as HCO3] | 1 | 0 | 0 | ||
| Phosphorus, total [as P] | 1 | 0 | 0 | ||
| Arsenic, total [as As] | 1 | 0 | 0 | ||
| Boron, total [as B] | 1 | 0 | 0 | ||
| Cadmium, total [as Cd] | 1 | 0 | 0 | ||
| Lead, total [as Pb] | 1 | 0 | 0 | ||
| Nickel, total [as Ni] | 1 | 0 | 0 | ||
| Silver, total [as Ag] | 1 | 0 | 0 | ||
| Zinc, total [as Zn] | 1 | 0 | 0 | ||
| Antimony, total [as Sb] | 1 | 0 | 0 | ||
| Selenium, total [as Se] | 1 | 0 | 0 | ||
| Hardness, Ca Mg Calculated [mg/L as CaCO3] | 1 | 0 | 0 | ||
| Mercury, dissolved [as Hg] | 1 | 0 | 0 | ||
| Mercury, total [as Hg] | 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 MN0055301.
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 MN0055301 there.
Nearby on the register
Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.