Clean Water Act discharge permit · NPDES IL0028321

SANITARY DISTRICT OF DECATUR MAIN STP, Decatur, IL: NPDES IL0028321 discharge permit, effluent exceedances, inspections, penalties

Administratively continuedPermit status
MajorDischarger class
15Pollutants under a numeric limit
6Pollutants with an effluent exceedance

SANITARY DISTRICT OF DECATUR MAIN STP, held by DECATUR SD MAIN STP, holds NPDES permit IL0028321, which discharges to Sangamon R, Unnamed Trib Spring Crk. EPA’s file records it issued April 20, 2007 and expiring June 30, 2012. 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	SANITARY DISTRICT OF DECATUR MAIN STP
Permittee as filed	DECATUR SD MAIN STP
NPDES ID	IL0028321
Permit status	Administratively continued (past its expiration date and still in force until reissued)
Permit type	Individual permit
Discharger class	Major discharger
Facility type	Publicly owned treatment works
Program	Publicly owned treatment works
Issued	April 20, 2007
Expiration date	June 30, 2012
Address	Decatur, IL 62522
Receiving water	SANGAMON R, UNNAMED TRIB SPRING CRK
Receiving water impaired	303(D) Listed
Subwatershed	Big Creek-Long Creek (HUC 071300060409)
Program components on file	Biosolids, CSO, POTW, Pretreatment
SIC	4952 – Sewerage Systems
Other EPA IDs (FRS)	RCRA handler IL1150155030

Cited to the EPA ICIS-NPDES permit file (ECHO download) and EPA’s NAICS/SIC and component files, the same download; cross-program IDs from EPA’s FRS facility-registry crosswalk.

Effluent limits and exceedances

15Pollutants on file
15Under a numeric limit
8With a violation of any kind
6With 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
Nickel, total [as Ni]	4	24	24	September 30, 2021	207% over the limit
Coliform, fecal general	2	23	23	May 31, 2026	20,900% over the limit
Chlorine, total residual	2	9	8	July 31, 2019	1,440% over the limit
Nitrogen, ammonia total [as N]	96	6	6	February 28, 2019	224% over the limit
pH	12	30	2	January 31, 2007
BOD, carbonaceous [5 day, 20 C]	8	2	2	February 28, 2021	173% over the limit
Solids, total suspended	13	15	0
BOD, 5-day, 20 deg. C	5	15	0
Zinc, total [as Zn]	8	0	0
Flow, in conduit or thru treatment plant	6	0	0
Flow	5	0	0
Flow, total	4	0	0
Oxygen, dissolved [DO]	2	0	0
Fluoride, total [as F]	2	0	0
Dichlorobromomethane	2	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

1Single-event violations

Date	What EPA recorded	Agency
July 9, 2025	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 IL0028321 there.

Nearby on the register

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

This public-records page covers Clean Water Act NPDES permit IL0028321, held by the Sanitary District of Decatur Main STP in Decatur, IL, and lists the permit as administratively continued with a Major Discharger class. The facts show 15 pollutants under a numeric limit and 6 pollutants with an effluent exceedance, and the permit was issued April 20, 2007 with an expiration date of June 30, 2012.