Clean Water Act discharge permit · NPDES IA0031232

INWOOD CITY OF STP, Inwood, IA: NPDES IA0031232 discharge permit, effluent exceedances, inspections, penalties

EffectivePermit status
MinorDischarger class
7Pollutants under a numeric limit
3Pollutants with an effluent exceedance
0Inspections on file
0Formal enforcement actions

INWOOD CITY OF STP, held by CITY OF INWOOD, holds NPDES permit IA0031232. EPA’s file records it issued September 1, 2024 and expiring August 31, 2029.

INWOOD CITY OF STP, Inwood, Iowa: Individual permit IA0031232, held by CITY OF INWOOD; Publicly owned treatment works; Effective; issued September 1, 2024, term to August 31, 2029, by STA; Sewage Treatment Facilities.

BOD, carbonaceous [5 day, 20 C]: 5 limits, 70 violations of any kind, 65 effluent exceedances, latest May 31, 2018, largest 1,154% over the limit.
Solids, total suspended: 10 limits, 67 violations of any kind, 60 effluent exceedances, latest April 30, 2011, largest 428% over the limit.
pH: 5 limits, 16 violations of any kind, 14 effluent exceedances, latest May 31, 2026.
Nitrogen, ammonia total [as N]: 48 limits, 4 violations of any kind, 0 effluent exceedances.
BOD, 5-day, 20 deg. C: 5 limits, 0 violations of any kind, 0 effluent exceedances.
E. coli: 3 limits, 0 violations of any kind, 0 effluent exceedances.
Depth of pond or reservoir in feet: 3 limits, 0 violations of any kind, 0 effluent exceedances.

Iowa holds 734 Publicly owned treatment works coverages of this permit type in EPA’s file; 718 were issued before IA0031232.

Coverages issued nearest IA0031232

July 1, 2024: DOUGHERTY CITY OF STP, Dougherty, IA0048978, held by CITY OF DOUGHERTY
August 1, 2024: BLAIRSTOWN CITY OF STP, Blairstown, IA0030660, held by CITY OF BLAIRSTOWN
August 1, 2024: WALL LAKE CITY OF STP, Wall Lake, IA0033065, held by CITY OF WALL LAKE
August 1, 2024: ADAIR CITY OF STP, Adair, IA0035416, held by CITY OF ADAIR
August 1, 2024: LE MARS CITY OF STP, Le Mars, IA0036536, held by CITY OF LE MARS
September 1, 2024: RIDGEWAY CITY OF STP, Ridgeway, IA0058726, held by City of Ridgeway
October 1, 2024: NORTHWOOD CITY OF STP, Northwood, IA0032395, held by CITY OF NORTHWOOD
October 1, 2024: PANAMA CITY OF STP, Panama, IA0071455, held by CITY OF PANAMA
October 1, 2024: JESUP, CITY OF STP (SOUTH), Jesup, IA0075302, held by CITY OF JESUP
November 1, 2024: EARLHAM CITY OF STP, Earlham, IA0027421, held by CITY OF EARLHAM

INWOOD CITY OF STP among its neighbors

EPA’s permit file holds 3 discharge permits in the Village of Inwood-Big Sioux River subwatershed (HUC 101702031904), IA0031232 among them. Its county holds 26, 0 of them major permits; IA0031232 is a minor permit.

Other permits in the Village of Inwood-Big Sioux River subwatershed (HUC 101702031904)

ARNEVA CATTLE, LLC, Inwood: IA0079502, minor permit, permit term to December 31, 2025
DAMON BAHNSON COMBINED OPERATION, Inwood: IA0084239, minor permit, permit term to July 31, 2024

Identity

Facility as filed	INWOOD CITY OF STP
Permittee as filed	CITY OF INWOOD
NPDES ID	IA0031232
Permit status	Effective
Permit type	Individual permit
Discharger class	Minor discharger
Facility type	Publicly owned treatment works
Program	Publicly owned treatment works
Issued	September 1, 2024
Expiration date	August 31, 2029
Issuing agency	STA
Address	Inwood, IA 51240
Subwatershed	Village of Inwood-Big Sioux River (HUC 101702031904)
NAICS	221320 – Sewage Treatment Facilities
SIC	4952 – Sewerage Systems

Effluent limits and exceedances

7Pollutants on file
7Under a numeric limit
4With a violation of any kind
3With 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
BOD, carbonaceous [5 day, 20 C]	5	70	65	May 31, 2018	1,154% over the limit
Solids, total suspended	10	67	60	April 30, 2011	428% over the limit
pH	5	16	14	May 31, 2026
Nitrogen, ammonia total [as N]	48	4	0
BOD, 5-day, 20 deg. C	5	0	0
E. coli	3	0	0
Depth of pond or reservoir in feet	3	0	0

Inspections, violations and enforcement

0Single-event violations

EPA’s single-event violation file, as loaded, holds no violation for NPDES IA0031232.

Inspections

EPA’s inspection file holds no inspection for NPDES IA0031232.

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 IA0031232.

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

This public-records page covers NPDES permit IA0031232 for INWOOD CITY OF STP in Inwood, IA, held by CITY OF INWOOD, with an effective status and an issue date of September 1, 2024 and expiration date of August 31, 2029. The page lists 7 pollutants on file, 3 of which are under a numeric limit, 4 with a violation of any kind, and 3 with an effluent exceedance.