Clean Water Act discharge permit · NPDES IL0020176
MOUNT CARROLL STP, CITY OF, Mount Carroll, IL: NPDES IL0020176 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 9Pollutants under a numeric limit
- 5Pollutants with an effluent exceedance
MOUNT CARROLL STP, CITY OF, held by MT CARROLL, CITY OF, holds NPDES permit IL0020176, which discharges to Carroll Creek. EPA’s file records it issued October 24, 2017 and expiring October 31, 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 | MOUNT CARROLL STP, CITY OF |
|---|---|
| Permittee as filed | MT CARROLL, CITY OF |
| NPDES ID | IL0020176 |
| 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 | October 24, 2017 |
| Expiration date | October 31, 2022 |
| Address | Mount Carroll, IL 61053 |
| Receiving water | CARROLL CREEK |
| Subwatershed | Carroll Creek (HUC 070600050902) |
| 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
- 10Pollutants on file
- 9Under a numeric limit
- 10With a violation of any kind
- 5With 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 | 4 | 72 | 50 | September 30, 2019 | 1,900% over the limit |
| Coliform, fecal general | 2 | 45 | 31 | August 31, 2016 | 99,999% over the limit |
| Nitrogen, ammonia total [as N] | 56 | 101 | 9 | October 31, 2012 | 105% over the limit |
| Solids, total suspended | 17 | 68 | 2 | March 31, 2010 | 13% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 16 | 61 | 1 | August 31, 2019 | 2% over the limit |
| Flow, in conduit or thru treatment plant | 6 | 50 | 0 | ||
| Oxygen, dissolved [DO] | 10 | 37 | 0 | ||
| pH | 4 | 28 | 0 | ||
| BOD, 5-day, 20 deg. C | 1 | 10 | 0 | ||
| Phosphorus, total [as P] | 0 | 4 | 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 IL0020176.
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
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- One state — $4,990/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 IL0020176 there.
Nearby on the register
Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.