Gilman City Of STP
Gilman, IA 50106 · Marshall County · Publicly Owned Treatment Works
- Average flow
- 0.02 MGD
- Design flow
- 1.05 MGD
- NPDES permit
- IA0029033
- Effective
- Permit expires
- November 2027
- Population served
- 532
- CWNS 2022
Gilman City Of STP is a publicly owned wastewater treatment works in Gilman, Marshall County, Iowa treating an average of 0.02 million gallons per day against a permitted design capacity of 1.05 MGD, serving about 532 residents. It discharges under NPDES permit IA0029033 (effective), which expires in November 2027, with 4 recorded violations in the last three years.
Treatment technology
2 treatment structures and unit processes identified at Gilman City Of STP.
Available with a free Klarifi account
See the full treatment train at Gilman City Of STP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 4
- Effluent violations
- 0
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
2 verified contacts for Gilman City Of STP, with validated emails and direct phone numbers.
Unlock 2 verified contacts
Names, validated emails and direct phone numbers for decision-makers at Gilman City Of STP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Iowa
Laurel · 6 mi away
0.02 MGD
Montour · 9 mi away
0.03 MGD
Le Grand · 10 mi away
0.08 MGD
Tama · 11 mi away
0.21 MGD
Grinnell · 11 mi away
1.35 MGD
Kellogg · 12 mi away
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Toledo · 13 mi away
0.43 MGD
Marshalltown · 14 mi away
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Gilman 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 April 23, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Tertiary treatment · Significant industrial user · all terms