Clean Water Act discharge permit · NPDES IL0032778

IAW - ARBURY HILLS STP, Mokena, IL: NPDES IL0032778 discharge permit, effluent exceedances, inspections, penalties

Administratively continuedPermit status
MinorDischarger class
11Pollutants under a numeric limit
5Pollutants with an effluent exceedance

IAW - ARBURY HILLS STP, held by ILLINOIS AMERICAN WATER COMPANY, holds NPDES permit IL0032778, which discharges to Hickory Creek. EPA’s file records it issued March 18, 2021 and expiring March 31, 2026. 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	IAW - ARBURY HILLS STP
Permittee as filed	ILLINOIS AMERICAN WATER COMPANY
NPDES ID	IL0032778
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	March 18, 2021
Expiration date	March 31, 2026
Address	Mokena, IL 60448
Receiving water	HICKORY CREEK
Subwatershed	Headwaters Hickory Creek (HUC 071200040601)
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
7With 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
Nitrogen, ammonia total [as N]	12	19	13	August 31, 2022	340% over the limit
Coliform, fecal general	1	11	11	June 30, 2026	4,200% over the limit
Oxygen, dissolved [DO]	5	7	7	July 31, 2024	5% over the limit
BOD, carbonaceous [5 day, 20 C]	4	11	3	October 31, 2021	38% over the limit
Solids, total suspended	5	2	2	February 28, 2023	10% over the limit
Chlorine, total residual	2	18	0
Chloride [as Cl]	1	1	0
Flow, in conduit or thru treatment plant	4	0	0
pH	2	0	0
Phosphorus, total [as P]	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 IL0032778.

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 IL0032778 there.

Nearby on the register

Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.

This public-records page covers Clean Water Act discharge permit NPDES IL0032778 for IAW - ARBURY HILLS STP in Mokena, IL, held by ILLINOIS AMERICAN WATER COMPANY and discharging to Hickory Creek. The permit's status is listed as administratively continued, with 11 pollutants under a numeric limit and 5 pollutants with an effluent exceedance.