Clean Water Act discharge permit · NPDES MI0020737
CHELSEA WWTP, Chelsea, MI: NPDES MI0020737 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MinorDischarger class
- 24Pollutants under a numeric limit
- 1Pollutants with an effluent exceedance
CHELSEA WWTP, held by City of Chelsea, holds NPDES permit MI0020737. EPA’s file records it issued September 28, 2018 and expiring October 1, 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 | CHELSEA WWTP |
|---|---|
| Permittee as filed | City of Chelsea |
| NPDES ID | MI0020737 |
| Permit status | Effective |
| Permit type | Individual permit |
| Discharger class | Minor discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | September 28, 2018 |
| Expiration date | October 1, 2022 |
| Issuing agency | State |
| Address | Chelsea, MI 48118 |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Letts Creek (HUC 040900050202) |
| Program components on file | Biosolids, POTW |
| NAICS | 221320 – Sewage Treatment Facilities |
| SIC | 4952 – Sewerage Systems |
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
- 25Pollutants on file
- 24Under a numeric limit
- 25With 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 |
|---|---|---|---|---|---|
| Oxygen, dissolved [DO] | 2 | 29 | 1 | January 31, 2023 | 10% over the limit |
| Phosphorus, total [as P] | 16 | 232 | 0 | ||
| Cyanide [A] | 3 | 93 | 0 | ||
| Nitrogen, ammonia total [as N] | 10 | 92 | 0 | ||
| BOD, carbonaceous [5 day, 20 C] | 12 | 88 | 0 | ||
| pH | 4 | 70 | 0 | ||
| Flow, in conduit or thru treatment plant | 2 | 70 | 0 | ||
| Coliform, fecal general | 2 | 70 | 0 | ||
| BOD, carb-5 day, 20 deg C, percent removal | 0 | 34 | 0 | ||
| Solids, total | 3 | 12 | 0 | ||
| Arsenic, dry weight | 3 | 12 | 0 | ||
| Selenium, dry weight | 3 | 12 | 0 | ||
| Copper, dry weight | 3 | 12 | 0 | ||
| Cadmium, dry weight | 3 | 12 | 0 | ||
| Nitrogen, total Kjeldahl | 3 | 12 | 0 | ||
| Molybdenum, sludge, total, dry weight [as Mo] | 3 | 12 | 0 | ||
| Zinc, sludge, total, dry weight [as Zn] | 3 | 12 | 0 | ||
| Lead, sludge, total, dry weight [as Pb] | 3 | 12 | 0 | ||
| Nickel, sludge, total, dry weight [as Ni] | 3 | 12 | 0 | ||
| Nitrogen, sludge, total, dry weight [as N] | 3 | 12 | 0 | ||
| Mercury, sludge, total, dry weight [as Hg] | 3 | 12 | 0 | ||
| Potassium, sludge, total, dry weight [as K] | 3 | 12 | 0 | ||
| Phosphorus, sludge, total, dry weight [as P] | 3 | 12 | 0 | ||
| Solids, suspended percent removal | 2 | 11 | 0 | ||
| Solids, total suspended | 8 | 8 | 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 |
|---|---|---|
| October 31, 2022 | Reporting Violations - Late Submittal of DMRs | ST6 |
| December 17, 2020 | Monitoring Violations - Frequency of Sampling 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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Nearby on the register
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- Every permit record in Chelsea, A to Z
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- Every permit record in Michigan, A to Z
Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.