Clean Water Act discharge permit · NPDES IL0020265

SOMONAUK STP, Somonauk, IL: NPDES IL0020265 discharge permit, effluent exceedances, inspections, penalties

Administratively continuedPermit status
MinorDischarger class
9Pollutants under a numeric limit
1Pollutants with an effluent exceedance

SOMONAUK STP, held by SOMONAUK, VILLAGE OF, holds NPDES permit IL0020265, which discharges to Somonauk Creek. EPA’s file records it issued August 22, 2018 and expiring August 31, 2023. 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	SOMONAUK STP
Permittee as filed	SOMONAUK, VILLAGE OF
NPDES ID	IL0020265
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	August 22, 2018
Expiration date	August 31, 2023
Address	Somonauk, IL 60552
Receiving water	SOMONAUK CREEK
Subwatershed	Buck Creek-Somonauk Creek (HUC 071200070403)

Cited to the EPA ICIS-NPDES permit file (ECHO download).

Effluent limits and exceedances

9Pollutants on file
9Under a numeric limit
4With a violation of any kind
1With 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	2	1	May 31, 2019	45% over the limit
Oxygen, dissolved [DO]	5	5	0
Chlorine, total residual	1	3	0
Coliform, fecal general	1	1	0
Nitrogen, ammonia total [as N]	8	0	0
Flow, in conduit or thru treatment plant	4	0	0
BOD, carbonaceous [5 day, 20 C]	4	0	0
pH	2	0	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 IL0020265.

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 IL0020265 there.

Nearby on the register

Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.

This public-records page covers NPDES permit IL0020265 for the SOMONAUK STP in Somonauk, IL, held by SOMONAUK, VILLAGE OF, which discharges to SOMONAUK CREEK within the Buck Creek-Somonauk Creek subwatershed (HUC 071200070403). The permit is listed as administratively continued, with a Minor discharger class and an Issued date of August 22, 2018 and an Expiration date of August 31, 2023. The page reports 9 pollutants on file, 9 of them under a numeric limit, 4 with a violation of any kind, and 1 with an effluent exceedance.