Marshalltown City Of STP
Marshalltown, IA · Marshall County · Publicly Owned Treatment Works
- Average flow
- —
- Design flow
- 17.44 MGD
- NPDES permit
- IA0038610
- Effective
- Permit expires
- October 2027
- Population served
- 27,591
- CWNS 2022
Marshalltown City Of STP is a publicly owned wastewater treatment works in Marshalltown, Marshall County, Iowa, serving about 27,591 residents. Treatment on site includes uncovered lagoons, biogas silos, biogas balloons. It discharges under NPDES permit IA0038610 (effective), which expires in October 2027, with 8 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Compliance snapshot (last 3 years)
- Total violations
- 8
- Effluent violations
- 8
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
4 verified contacts for Marshalltown City Of STP, with validated emails and direct phone numbers.
Unlock 4 verified contacts (1 more than shown)
Names, validated emails and direct phone numbers for decision-makers at Marshalltown City Of STP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Iowa
Albion · 5 mi away
—
Le Grand · 8 mi away
—
Liscomb · 10 mi away
—
Beaman · 11 mi away
—
Montour · 11 mi away
—
Garwin · 11 mi away
—
Garwin · 11 mi away
—
Laurel · 12 mi away
—
Marshalltown 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 September 11, 2026; facility record last updated August 18, 2026.