Clean Water Act discharge permit · NPDES MI0001121
GM-BAY CITY PLANT, Bay City, MI: NPDES MI0001121 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 7Pollutants under a numeric limit
- 1Pollutants with an effluent exceedance
- 1Inspections on file
- 0Formal enforcement actions
GM-BAY CITY PLANT, held by General Motors, holds NPDES permit MI0001121, which discharges to Saginaw River. EPA’s file records it issued November 19, 2021 and expiring October 1, 2025. 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 | GM-BAY CITY PLANT |
|---|---|
| Permittee as filed | General Motors |
| NPDES ID | MI0001121 |
| 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 19, 2021 |
| Expiration date | October 1, 2025 |
| Issuing agency | State |
| Address | Bay City, MI 48708 |
| Receiving water | Saginaw River |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | City of Bay City-Saginaw River (HUC 040802060204) |
| NAICS | 333517 – Machine Tool Manufacturing |
| SIC | 3542 – Machine Tools, Metal Forming Types |
| Other EPA IDs (FRS) | RCRA handler MIK844848887; ICIS-AIR source MI00000000000B2460 |
Cited to the EPA ICIS-NPDES permit file (ECHO download) and EPA’s NAICS/SIC and component files, the same download; cross-program IDs from EPA’s FRS facility-registry crosswalk.
Effluent limits and exceedances
- 7Pollutants on file
- 7Under a numeric limit
- 6With a violation of any kind
- 1With 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 |
|---|---|---|---|---|---|
| Chlorine, total residual | 1 | 19 | 1 | July 31, 2003 | 82% over the limit |
| Polychlorinated biphenyls [PCBs] | 2 | 185 | 0 | ||
| Phosphorus, total [as P] | 4 | 46 | 0 | ||
| pH | 2 | 40 | 0 | ||
| Flow, in conduit or thru treatment plant | 2 | 40 | 0 | ||
| Temperature, water deg. fahrenheit | 2 | 21 | 0 | ||
| Outfall observation,visual, y/n response | 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 MI0001121.
Inspections
| Date | What EPA recorded | Agency |
|---|---|---|
| August 21, 2026 | Reconnaissance without Sampling | S |
Formal enforcement and penalties
0 formal actions, 0 of them with a penalty assessed. Federal and state penalties are separate figures from separate authorities and are shown as each was filed, never added together.
Informal enforcement
EPA’s informal enforcement file holds no action for NPDES MI0001121.
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
One permit holder, $99/month. Watch the register for one permit holder and the places and receiving waters tied to its permits. Choose “One permit holder” and enter this permit’s NPDES ID, MI0001121.
Start the watch
- One permit holder — $99/month
- One watershed — $2,990/year
- One state — $4,990/year
- The whole register — $18,000/year
How we handle your data → Privacy
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 MI0001121 there.
Nearby on the register
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- Every permit record in Michigan, A to Z
Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.