Clean Water Act discharge permit · NPDES ILG580276
MASON STP, TOWN OF, Mason, IL: NPDES ILG580276 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 9Pollutants under a numeric limit
- 4Pollutants with an effluent exceedance
MASON STP, TOWN OF, held by MASON, TOWN OF, holds NPDES permit ILG580276, which discharges to Unnamed Tributary Of Second Creek. EPA’s file records it issued June 16, 2014 and expiring June 30, 2018. The status and dates are as EPA’s permit file stood when Velarion loaded it (September 15, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.
Identity
| Facility as filed | MASON STP, TOWN OF |
|---|---|
| Permittee as filed | MASON, TOWN OF |
| NPDES ID | ILG580276 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Coverage under a general permit |
| Discharger class | Minor discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | June 16, 2014 |
| Expiration date | June 30, 2018 |
| Address | Mason, IL 62443 |
| Receiving water | UNNAMED TRIBUTARY OF SECOND CREEK |
| Subwatershed | Second Creek (HUC 051201140405) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 9Pollutants on file
- 9Under a numeric limit
- 8With 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 |
|---|---|---|---|---|---|
| Oxygen, dissolved [DO] | 1 | 12 | 12 | June 30, 2026 | 58% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 4 | 10 | 6 | February 29, 2024 | 35% over the limit |
| Solids, total suspended | 5 | 9 | 5 | May 31, 2017 | 214% over the limit |
| pH | 2 | 6 | 4 | February 29, 2016 | |
| Flow, in conduit or thru treatment plant | 4 | 2 | 0 | ||
| Nitrogen, ammonia total [as N] | 1 | 1 | 0 | ||
| Chlorine, total residual | 1 | 1 | 0 | ||
| Coliform, fecal general | 1 | 1 | 0 | ||
| BOD, 5-day, 20 deg. C | 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
- 0Single-event violations
EPA’s single-event violation file, as loaded, holds no violation for NPDES ILG580276.
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, ILG580276.
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 ILG580276 there.
Nearby on the register
Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.