Clean Water Act discharge permit · NPDES IL0031798
AQUA ILLINOIS - WILLOWBROOK STP, Crete, IL: NPDES IL0031798 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 9Pollutants under a numeric limit
- 4Pollutants with an effluent exceedance
AQUA ILLINOIS - WILLOWBROOK STP, held by AQUA ILLINOIS INC, holds NPDES permit IL0031798, which discharges to Klemme Creek. EPA’s file records it issued January 9, 2019 and expiring December 31, 2023. 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 | AQUA ILLINOIS - WILLOWBROOK STP |
|---|---|
| Permittee as filed | AQUA ILLINOIS INC |
| NPDES ID | IL0031798 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Minor discharger |
| Facility type | Not a publicly owned treatment works |
| Issued | January 9, 2019 |
| Expiration date | December 31, 2023 |
| Address | Crete, IL 60417 |
| Receiving water | KLEMME CREEK |
| Subwatershed | Plum Creek Forest Preserve-Plum Creek (HUC 071200030302) |
| 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
- 9Pollutants on file
- 9Under a numeric limit
- 5With a violation of any kind
- 4With 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 |
|---|---|---|---|---|---|
| Solids, total suspended | 5 | 10 | 10 | March 31, 2025 | 111% over the limit |
| Coliform, fecal general | 1 | 4 | 3 | October 31, 2024 | 505% over the limit |
| Chlorine, total residual | 2 | 3 | 1 | March 31, 2025 | 560% over the limit |
| pH | 2 | 1 | 1 | September 30, 2002 | |
| Flow, in conduit or thru treatment plant | 4 | 23 | 0 | ||
| Oxygen, dissolved [DO] | 5 | 0 | 0 | ||
| BOD, carbonaceous [5 day, 20 C] | 4 | 0 | 0 | ||
| BOD, 5-day, 20 deg. C | 1 | 0 | 0 | ||
| Nitrogen, ammonia total [as N] | 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
- 4Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| August 24, 2026 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | ST6 |
| August 24, 2026 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | ST6 |
| June 1, 2026 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | ST6 |
| January 1, 2026 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | 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
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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 IL0031798 there.
Nearby on the register
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Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.