Clean Water Act discharge permit · NPDES WI0030031
PLYMOUTH CITY UTIL COMMISSION WWTF, Plymouth, WI: NPDES WI0030031 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 11Pollutants under a numeric limit
- 6Pollutants with an effluent exceedance
PLYMOUTH CITY UTIL COMMISSION WWTF, held by Plymouth City Utilities Commission, holds NPDES permit WI0030031, which discharges to Mullet R. EPA’s file records it issued July 22, 2013 and expiring June 30, 2018. 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 | PLYMOUTH CITY UTIL COMMISSION WWTF |
|---|---|
| Permittee as filed | Plymouth City Utilities Commission |
| NPDES ID | WI0030031 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | July 22, 2013 |
| Expiration date | June 30, 2018 |
| Address | Plymouth, WI 53073 |
| Receiving water | MULLET R |
| Subwatershed | Lower Mullet River (HUC 040301010903) |
| Program components on file | Biosolids, POTW |
| 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
- 11Pollutants on file
- 11Under a numeric limit
- 9With 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] | 36 | 18 | 18 | June 30, 2018 | 270% over the limit |
| BOD, 5-day, 20 deg. C | 12 | 17 | 17 | April 30, 2026 | 265% over the limit |
| Solids, total suspended | 12 | 12 | 11 | February 28, 2026 | 3,086% over the limit |
| Phosphorus, total [as P] | 4 | 3 | 3 | July 31, 2025 | 15% over the limit |
| Oxygen, dissolved [DO] | 1 | 2 | 2 | June 30, 2018 | 7% over the limit |
| pH | 2 | 1 | 1 | July 31, 2018 | |
| Mercury, total recoverable | 2 | 173 | 0 | ||
| Chloride [as Cl] | 2 | 87 | 0 | ||
| Coliform, fecal general | 1 | 44 | 0 | ||
| Temperature, water deg. fahrenheit | 2 | 0 | 0 | ||
| Flow, in conduit or thru treatment plant | 2 | 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
- 4Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| July 16, 2025 | WW SSO - Discharge to Waters | ST6 |
| June 22, 2024 | WW SSO - Discharge to Waters | ST6 |
| January 9, 2023 | WW SSO - Discharge to Waters | ST6 |
| March 14, 2019 | WW SSO - Discharge to Waters | 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.
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, WI0030031.
Start the watch
- One permit holder — $99/month
- One watershed — $2,990/year
- One state — $4,990/year
- The whole register — $18,000/year
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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 WI0030031 there.
Nearby on the register
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- Every permit record in Wisconsin, A to Z
Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.