Clean Water Act discharge permit · NPDES IA0035203

AUDUBON CITY OF STP, Audubon, IA: NPDES IA0035203 discharge permit, effluent exceedances, inspections, penalties

EffectivePermit status
MinorDischarger class
11Pollutants under a numeric limit
4Pollutants with an effluent exceedance
0Inspections on file
0Formal enforcement actions

AUDUBON CITY OF STP, held by CITY OF AUDUBON, holds NPDES permit IA0035203. EPA’s file records it issued January 1, 2024 and expiring December 31, 2028.

AUDUBON CITY OF STP, Audubon, Iowa: Individual permit IA0035203, held by CITY OF AUDUBON; Publicly owned treatment works; Effective; issued January 1, 2024, term to December 31, 2028, by STA; Sewage Treatment Facilities.

Nitrogen, ammonia total [as N]: 48 limits, 7 violations of any kind, 3 effluent exceedances, latest February 28, 2025, largest 186% over the limit.
Oxygen, dissolved [DO]: 1 limit, 3 violations of any kind, 3 effluent exceedances, latest June 30, 2016, largest 35% over the limit.
pH: 5 limits, 1 violation of any kind, 1 effluent exceedance, latest September 30, 2025.
Chloride [as Cl]: 4 limits, 1 violation of any kind, 1 effluent exceedance, latest January 31, 2024, largest 1% over the limit.
Solids, total suspended: 9 limits, 0 violations of any kind, 0 effluent exceedances.
BOD, 5-day, 20 deg. C: 5 limits, 0 violations of any kind, 0 effluent exceedances.
Nitrogen, total [as N]: 5 limits, 0 violations of any kind, 0 effluent exceedances.
Nitrogen, Kjeldahl, total [as N]: 5 limits, 0 violations of any kind, 0 effluent exceedances.
Phosphorus, total [as P]: 5 limits, 0 violations of any kind, 0 effluent exceedances.
BOD, carbonaceous [5 day, 20 C]: 4 limits, 0 violations of any kind, 0 effluent exceedances.
E. coli: 1 limit, 0 violations of any kind, 0 effluent exceedances.

Iowa holds 734 Publicly owned treatment works coverages of this permit type in EPA’s file; 708 were issued before IA0035203.

Coverages issued nearest IA0035203

March 1, 2023: GOODELL CITY OF STP, Goodell, IA0082562, held by CITY OF GOODELL
April 1, 2023: LOGAN CITY OF STP, Logan, IA0058599, held by CITY OF LOGAN
May 1, 2023: TOLEDO CITY OF STP, Toledo, IA0033103, held by CITY OF TOLEDO
September 1, 2023: BROOKLYN CITY OF STP, Brooklyn, IA0020958, held by CITY OF BROOKLYN
November 1, 2023: LECLAIRE CITY OF STP, Le Claire, IA0022012, held by CITY OF LECLAIRE
May 1, 2024: MOUNT AYR CITY OF STP, Mount Ayr, IA0023574, held by CITY OF MOUNT AYR
May 1, 2024: ALTON CITY OF STP, Alton, IA0028932, held by CITY OF ALTON
June 1, 2024: NORTH ENGLISH CITY OF STP, North English, IA0034282, held by CITY OF NORTH ENGLISH
July 1, 2024: MOUNT PLEASANT CITY OF STP (MAIN), Mount Pleasant, IA0047970, held by CITY OF MOUNT PLEASANT
July 1, 2024: DOUGHERTY CITY OF STP, Dougherty, IA0048978, held by CITY OF DOUGHERTY

AUDUBON CITY OF STP among its neighbors

EPA’s permit file holds 1 discharge permits in the Bluegrass Creek subwatershed (HUC 102400030203), IA0035203 among them. Its county holds 5, 0 of them major permits; IA0035203 is a minor permit.

Identity

Facility as filed	AUDUBON CITY OF STP
Permittee as filed	CITY OF AUDUBON
NPDES ID	IA0035203
Permit status	Effective
Permit type	Individual permit
Discharger class	Minor discharger
Facility type	Publicly owned treatment works
Program	Publicly owned treatment works
Issued	January 1, 2024
Expiration date	December 31, 2028
Issuing agency	STA
Address	Audubon, IA 50025
Subwatershed	Bluegrass Creek (HUC 102400030203)
NAICS	221320 – Sewage Treatment Facilities
SIC	4952 – Sewerage Systems

Effluent limits and exceedances

11Pollutants on file
11Under a numeric limit
4With 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
Nitrogen, ammonia total [as N]	48	7	3	February 28, 2025	186% over the limit
Oxygen, dissolved [DO]	1	3	3	June 30, 2016	35% over the limit
pH	5	1	1	September 30, 2025
Chloride [as Cl]	4	1	1	January 31, 2024	1% over the limit
Solids, total suspended	9	0	0
BOD, 5-day, 20 deg. C	5	0	0
Nitrogen, total [as N]	5	0	0
Nitrogen, Kjeldahl, total [as N]	5	0	0
Phosphorus, total [as P]	5	0	0
BOD, carbonaceous [5 day, 20 C]	4	0	0
E. coli	1	0	0

Inspections, violations and enforcement

0Single-event violations

EPA’s single-event violation file, as loaded, holds no violation for NPDES IA0035203.

Inspections

EPA’s inspection file holds no inspection for NPDES IA0035203.

Formal enforcement and penalties

0 formal actions, 0 of them with a penalty assessed. Federal and state penalties are separate figures from separate authorities and are shown as each was filed, never added together.

Informal enforcement

EPA’s informal enforcement file holds no action for NPDES IA0035203.

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

This public-records page covers the Clean Water Act NPDES discharge permit IA0035203 for AUDUBON CITY OF STP in Audubon, IA, held by CITY OF AUDUBON as an effective individual permit for a minor discharger, with the status and dates as they stood when the file was loaded on October 14, 2026. The page lists 11 pollutants on file, 11 of them under a numeric limit, and 4 with a violation of any kind, including 4 with an effluent exceedance.