Clean Water Act discharge permit · NPDES MI0021717
WILLIAMSTON WWTP, Williamston, MI: NPDES MI0021717 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 24Pollutants under a numeric limit
- 6Pollutants with an effluent exceedance
- 0Inspections on file
- 0Formal enforcement actions
WILLIAMSTON WWTP, held by City of Williamston, holds NPDES permit MI0021717, which discharges to Red Cedar River. EPA’s file records it issued November 29, 2018 and expiring October 1, 2022.
WILLIAMSTON WWTP, Williamston, Michigan: Individual permit MI0021717, held by City of Williamston; Publicly owned treatment works; Administratively continued (past its expiration date and still in force until reissued); issued November 29, 2018, term to October 1, 2022, by State; discharges to Red Cedar River.
- Nitrogen, ammonia total [as N]: 8 limits, 101 violations of any kind, 10 effluent exceedances, latest May 31, 2025, largest 658% over the limit.
- Solids, total suspended: 8 limits, 117 violations of any kind, 7 effluent exceedances, latest May 31, 2020, largest 498% over the limit.
- Coliform, fecal general: 2 limits, 59 violations of any kind, 3 effluent exceedances, latest April 30, 2025, largest 99,999% over the limit.
- Solids, suspended percent removal: 2 limits, 19 violations of any kind, 3 effluent exceedances, latest March 31, 2019, largest 99,999% over the limit.
- BOD, carbonaceous [5 day, 20 C]: 12 limits, 198 violations of any kind, 2 effluent exceedances, latest May 31, 2020, largest 15% over the limit.
- BOD, carb-5 day, 20 deg C, percent removal: 2 limits, 13 violations of any kind, 1 effluent exceedance, latest April 30, 2018, largest 13% over the limit.
- pH: 2 limits, 54 violations of any kind, 0 effluent exceedances.
- Flow, in conduit or thru treatment plant: 2 limits, 54 violations of any kind, 0 effluent exceedances.
- Oxygen, dissolved [DO]: 2 limits, 49 violations of any kind, 0 effluent exceedances.
- Phosphorus, total [as P]: 4 limits, 27 violations of any kind, 0 effluent exceedances.
- Solids, total: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Arsenic, dry weight: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Selenium, dry weight: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Copper, dry weight: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Cadmium, dry weight: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Nitrogen, total Kjeldahl: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Molybdenum, sludge, total, dry weight [as Mo]: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Zinc, sludge, total, dry weight [as Zn]: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Lead, sludge, total, dry weight [as Pb]: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Nickel, sludge, total, dry weight [as Ni]: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Nitrogen, sludge, total, dry weight [as N]: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Mercury, sludge, total, dry weight [as Hg]: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Potassium, sludge, total, dry weight [as K]: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- Phosphorus, sludge, total, dry weight [as P]: 3 limits, 3 violations of any kind, 0 effluent exceedances.
- July 27, 2023: Monitoring Violations - Invalid/Unrepresentative Sample (ST6).
- October 31, 2017: Reporting Violations - Late Submittal of DMRs (ST6).
Michigan holds 200 Publicly owned treatment works coverages of this permit type in EPA’s file; 111 were issued before MI0021717.
Coverages issued nearest MI0021717
- October 23, 2018: DIMONDALE/WINDSOR WWTP, Dimondale, MI0053562, held by Village of Dimondale
- October 23, 2018: GLADSTONE WWTP, Gladstone, MI0057676, held by City of Gladstone
- November 2, 2018: LEONI TWP WWTP, Jackson, MI0045942, held by Leoni Township
- November 7, 2018: SOUTH HURON VALLEY UTILITY AUTHORITY WWTP, Rockwood, MI0043800, held by South Huron Valley Utility Authority
- November 27, 2018: GRANT WWTP, Grant, MI0023035, held by City of Grant
- November 29, 2018: ROLLIN-WOODSTOCK WWTP, Addison, MI0027669, held by Lenawee County Drain Commission, as Agent for Rollin-Woodstock Sanitary Drain Dr
- November 30, 2018: FOWLERVILLE WWTP, Fowlerville, MI0020664, held by Village of Fowlerville
- December 17, 2018: HANDY TWP WWTP, Fowlerville, MI0056839, held by Handy Township
- December 21, 2018: PORTAGE LAKE AUTHORITY WWTP, Houghton, MI0020061, held by Portage Lake Water and Sewage Authority
- December 21, 2018: ONAWAY WWTP, Onaway, MI0055522, held by City of Onaway
WILLIAMSTON WWTP among its neighbors
EPA’s permit file holds 3 discharge permits in the Coon Creek-Red Cedar River subwatershed (HUC 040500040503), MI0021717 among them. Its county holds 38, 5 of them major permits; MI0021717 is a minor permit.
Other permits in the Coon Creek-Red Cedar River subwatershed (HUC 040500040503)
- OLD NATION BREWING COMPANY, Williamston: MIS310755, minor permit, permit term to April 1, 2023
- R N FINK MFG CO, Williamston: MIG250081, minor permit, discharging to Frost Drain, permit term to April 1, 2023
Identity
| Facility as filed | WILLIAMSTON WWTP |
|---|---|
| Permittee as filed | City of Williamston |
| NPDES ID | MI0021717 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Minor discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | November 29, 2018 |
| Expiration date | October 1, 2022 |
| Issuing agency | State |
| Address | Williamston, MI 48895 |
| Receiving water | Red Cedar River |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Coon Creek-Red Cedar River (HUC 040500040503) |
Effluent limits and exceedances
- 24Pollutants on file
- 24Under a numeric limit
- 24With a violation of any kind
- 6With 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 |
|---|---|---|---|---|---|
| Nitrogen, ammonia total [as N] | 8 | 101 | 10 | May 31, 2025 | 658% over the limit |
| Solids, total suspended | 8 | 117 | 7 | May 31, 2020 | 498% over the limit |
| Coliform, fecal general | 2 | 59 | 3 | April 30, 2025 | 99,999% over the limit |
| Solids, suspended percent removal | 2 | 19 | 3 | March 31, 2019 | 99,999% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 12 | 198 | 2 | May 31, 2020 | 15% over the limit |
| BOD, carb-5 day, 20 deg C, percent removal | 2 | 13 | 1 | April 30, 2018 | 13% over the limit |
| pH | 2 | 54 | 0 | ||
| Flow, in conduit or thru treatment plant | 2 | 54 | 0 | ||
| Oxygen, dissolved [DO] | 2 | 49 | 0 | ||
| Phosphorus, total [as P] | 4 | 27 | 0 | ||
| Solids, total | 3 | 3 | 0 | ||
| Arsenic, dry weight | 3 | 3 | 0 | ||
| Selenium, dry weight | 3 | 3 | 0 | ||
| Copper, dry weight | 3 | 3 | 0 | ||
| Cadmium, dry weight | 3 | 3 | 0 | ||
| Nitrogen, total Kjeldahl | 3 | 3 | 0 | ||
| Molybdenum, sludge, total, dry weight [as Mo] | 3 | 3 | 0 | ||
| Zinc, sludge, total, dry weight [as Zn] | 3 | 3 | 0 | ||
| Lead, sludge, total, dry weight [as Pb] | 3 | 3 | 0 | ||
| Nickel, sludge, total, dry weight [as Ni] | 3 | 3 | 0 | ||
| Nitrogen, sludge, total, dry weight [as N] | 3 | 3 | 0 | ||
| Mercury, sludge, total, dry weight [as Hg] | 3 | 3 | 0 | ||
| Potassium, sludge, total, dry weight [as K] | 3 | 3 | 0 | ||
| Phosphorus, sludge, total, dry weight [as P] | 3 | 3 | 0 |
Inspections, violations and enforcement
- 2Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| July 27, 2023 | Monitoring Violations - Invalid/Unrepresentative Sample | ST6 |
| October 31, 2017 | Reporting Violations - Late Submittal of DMRs | ST6 |
Inspections
EPA’s inspection file holds no inspection for NPDES MI0021717.
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 MI0021717.
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Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.