What is the address of Irwin City Of STP?

The address on the plant’s EPA facility record is 1900th And Redwood Road, Irwin, IA 51446, in Shelby County. Its coordinates are 41.7787, -95.2274. For some plants the record holds the utility’s mailing address rather than the plant gate.

How much wastewater does Irwin City Of STP treat?

Irwin City Of STP is permitted for a design flow of 0.1 MGD. Its average daily flow is not available in the current EPA data.

What treatment technology does Irwin City Of STP use?

Klarifi has identified one treatment structure or unit process at the Irwin facility. The full treatment train, with exact unit counts, is shown in Klarifi with a free account.

What is the NPDES permit for Irwin City Of STP?

The facility discharges under NPDES permit IA0021024, currently effective, expiring May 2027.

Is Irwin City Of STP in compliance?

Discharge monitoring reports show no violations at Irwin City Of STP in the last three years.

Who operates Irwin City Of STP and how do I contact them?

Irwin City Of STP is a publicly owned treatment works in Irwin, Iowa. Klarifi lists 1 verified decision-maker contact for this facility, available with a free trial.

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Irwin City Of STP

1900th And Redwood Road, Irwin, IA 51446 · Shelby County · Publicly Owned Treatment Works

Average flow: —

Design flow: 0.1 MGD

NPDES permit: IA0021024; Effective

Permit expires: May 2027

Population served: 319; CWNS 2022

Irwin City Of STP is a publicly owned wastewater treatment works in Irwin, Shelby County, Iowa, serving about 319 residents. It discharges under NPDES permit IA0021024 (effective), which expires in May 2027, with 0 recorded violations in the last three years.

Treatment technology

One treatment structure or unit process identified at Irwin City Of STP.

Available with a free Klarifi account

See the full treatment train at Irwin City Of STP: structures, unit processes and planned upgrades, with exact unit counts.

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Compliance snapshot (last 3 years)

Total violations: 0

Effluent violations: 0

Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.

Key contacts

1 verified contact for Irwin City Of STP, with validated emails and direct phone numbers.

Unlock 1 verified contact

Names, validated emails and direct phone numbers for decision-makers at Irwin City Of STP, plus the full compliance history and discharge data.

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Nearby wastewater treatment plants in Iowa

Defiance City Of STP

Defiance · 6 mi away

—

Manilla WWTP

Manilla · 7 mi away

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Earling City Of STP

Earling · 11 mi away

0.04 MGD

Harlan City Of STP

Harlan · 11 mi away

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Manning WWTP

Manning · 12 mi away

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Kimballton City Of STP

Kimballton · 13 mi away

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Audubon City Of STP

Audubon · 16 mi away

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Elk Horn City Of STP

Elk Horn · 16 mi away

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Irwin City Of STP: frequently asked questions

Sources and methodology

Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.

Data refreshed October 26, 2026; facility record last updated March 28, 2025.

Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Activated sludge · Oxidation ditch · all terms

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