Clean Water Act discharge permit · NPDES IA0070866

IOWA CITY, CITY OF (SOUTH) STP, Iowa City, IA: NPDES IA0070866 discharge permit, effluent exceedances, inspections, penalties

Administratively continuedPermit status
MajorDischarger class
13Pollutants under a numeric limit
5Pollutants with an effluent exceedance
0Inspections on file
0Formal enforcement actions

IOWA CITY, CITY OF (SOUTH) STP, held by CITY OF IOWA CITY, holds NPDES permit IA0070866. EPA’s file records it issued May 1, 2020 and expiring April 30, 2025.

IOWA CITY, CITY OF (SOUTH) STP, Iowa City, Iowa: Individual permit IA0070866, held by CITY OF IOWA CITY; Publicly owned treatment works; Administratively continued (past its expiration date and still in force until reissued); issued May 1, 2020, term to April 30, 2025, by STA; Sewage Treatment Facilities.

pH: 5 limits, 19 violations of any kind, 12 effluent exceedances, latest May 31, 2026.
Zinc, total [as Zn]: 4 limits, 17 violations of any kind, 7 effluent exceedances, latest June 30, 2017, largest 48% over the limit.
Solids, total suspended: 9 limits, 14 violations of any kind, 2 effluent exceedances, latest April 30, 2017, largest 211% over the limit.
Nitrogen, ammonia total [as N]: 48 limits, 6 violations of any kind, 2 effluent exceedances, latest June 30, 2023, largest 153% over the limit.
Oxygen, dissolved [DO]: 12 limits, 3 violations of any kind, 2 effluent exceedances, latest November 30, 2020, largest 81% over the limit.
BOD, carbonaceous [5 day, 20 C]: 4 limits, 12 violations of any kind, 0 effluent exceedances.
Toxicity [acute], Ceriodaphnia dubia: 1 limit, 2 violations of any kind, 0 effluent exceedances.
Toxicity [acute], Pimephales promelas [Fathead Minnow]: 1 limit, 2 violations of any kind, 0 effluent exceedances.
Nitrogen, total [as N]: 20 limits, 0 violations of any kind, 0 effluent exceedances.
Phosphorus, total [as P]: 20 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, Kjeldahl, total [as N]: 5 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; 526 were issued before IA0070866. CITY OF IOWA CITY holds 4 permits in Iowa.

Other permits held by CITY OF IOWA CITY

IOWA CITY WATER TREATMENT PLANT, Iowa City: IA0076082, issued January 1, 2019
IOWA CITY, CITY OF MS4, Iowa City: IA0078298, issued June 1, 2014
CITY OF IOWA CITY, Iowa City: IAL070866, issued January 1, 2021

Coverages issued nearest IA0070866

May 1, 2020: MORAVIA CITY OF STP, Moravia, IA0056693, held by CITY OF MORAVIA
May 1, 2020: MARBLE ROCK CITY OF STP, Marble Rock, IA0057207, held by CITY OF MARBLE ROCK
May 1, 2020: IONIA CITY OF STP, Ionia, IA0058777, held by CITY OF IONIA
May 1, 2020: DAVIS CITY, CITY OF STP (SIRWA), Davis City, IA0060232, held by SOUTHERN IOWA RURAL WATER ASSOCIATION
May 1, 2020: ASBURY CITY OF STP, Asbury, IA0069922, held by CITY OF ASBURY
May 1, 2020: WESTGATE, CITY OF-STP, Westgate, IA0075353, held by CITY OF WESTGATE
June 1, 2020: MAQUOKETA CITY OF STP, Maquoketa, IA0024481, held by CITY OF MAQUOKETA
June 1, 2020: GILBERT, CITY OF STP, Gilbert, IA0025968, held by CITY OF GILBERT
June 1, 2020: AVOCA CITY OF STP, Avoca, IA0030708, held by CITY OF AVOCA
June 1, 2020: WINTHROP CITY OF STP, Winthrop, IA0032808, held by CITY OF WINTHROP

IOWA CITY, CITY OF (SOUTH) STP among its neighbors

EPA’s permit file holds 19 discharge permits in the Ralston Creek-Iowa River subwatershed (HUC 070802090703), IA0070866 among them. Its county holds 47, 4 of them major permits; IA0070866 is a major permit.

Other permits in the Ralston Creek-Iowa River subwatershed (HUC 070802090703)

CITY OF IOWA CITY, Iowa City: IAL042617, minor permit, permit term to December 31, 2025
CITY OF IOWA CITY, Iowa City: IAL070866, minor permit, permit term to December 31, 2025
CORALVILLE CITY OF STP, Coralville: IA0020788, major permit, permit term to March 31, 2026
ENTERPRISE PRODUCTS OPERATING LLC, Des Moines: IA0078093, minor permit, permit term to July 31, 2019
IOWA CITY REGENCY MOBILE HOME PARK STP, Iowa City: IA0063274, minor permit, permit term to November 30, 2026
IOWA CITY WATER TREATMENT PLANT, Iowa City: IA0076082, minor permit, permit term to December 31, 2023
IOWA CITY, CITY OF MS4, Iowa City: IA0078298, minor permit, permit term to May 31, 2019
KUM & GO #201, Coralville: IA0066770, minor permit, permit term to June 30, 2015
LAKE RIDGE, Iowa City: IA0074284, minor permit, permit term to October 31, 2024
MAKADA SUBDIVISION-STP, Iowa City: IA0073733, minor permit, permit term to October 31, 2025

Identity

Facility as filed	IOWA CITY, CITY OF (SOUTH) STP
Permittee as filed	CITY OF IOWA CITY
NPDES ID	IA0070866
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	May 1, 2020
Expiration date	April 30, 2025
Issuing agency	STA
Address	Iowa City, IA 52240
Subwatershed	Ralston Creek-Iowa River (HUC 070802090703)
Program components on file	Biosolids, POTW, Pretreatment
NAICS	221320 – Sewage Treatment Facilities
SIC	4952 – Sewerage Systems

Effluent limits and exceedances

13Pollutants on file
13Under a numeric limit
8With 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
pH	5	19	12	May 31, 2026
Zinc, total [as Zn]	4	17	7	June 30, 2017	48% over the limit
Solids, total suspended	9	14	2	April 30, 2017	211% over the limit
Nitrogen, ammonia total [as N]	48	6	2	June 30, 2023	153% over the limit
Oxygen, dissolved [DO]	12	3	2	November 30, 2020	81% over the limit
BOD, carbonaceous [5 day, 20 C]	4	12	0
Toxicity [acute], Ceriodaphnia dubia	1	2	0
Toxicity [acute], Pimephales promelas [Fathead Minnow]	1	2	0
Nitrogen, total [as N]	20	0	0
Phosphorus, total [as P]	20	0	0
BOD, 5-day, 20 deg. C	5	0	0
Nitrogen, Kjeldahl, total [as N]	5	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 IA0070866.

Inspections

EPA’s inspection file holds no inspection for NPDES IA0070866.

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 IA0070866.

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

This public-records page covers the NPDES IA0070866 discharge permit for the Iowa City, City of (South) STP in Iowa City, IA, held by the City of Iowa City, with the permit listed as administratively continued past its April 30, 2025 expiration date. The page reports a Major Discharger class, 5 pollutants with an effluent exceedance, and 13 pollutants under a numeric limit, within the Ralston Creek-Iowa River (HUC 070802090703) subwatershed.