Decorah City Of STP
1766 Old Stage Road, Decorah, IA 52101 · Winneshiek County · Publicly Owned Treatment Works
- Average flow
- 0.92 MGD
- Design flow
- 4.83 MGD
- NPDES permit
- IA0035220
- Effective
- Permit expires
- October 2027
- Population served
- 8,427
- CWNS 2022
Decorah City Of STP is a publicly owned wastewater treatment works in Decorah, Winneshiek County, Iowa treating an average of 0.92 million gallons per day against a permitted design capacity of 4.83 MGD, serving about 8,427 residents. It discharges under NPDES permit IA0035220 (effective), which expires in October 2027, with 3 recorded violations in the last three years.
Treatment technology
2 treatment structures and unit processes identified at Decorah City Of STP.
Available with a free Klarifi account
See the full treatment train at Decorah City Of STP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 3
- Effluent violations
- 3
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Industrial users and pretreatment
Industries that discharge process wastewater to Decorah City Of STP, from the plant's pretreatment programme records.
- Industrial users
- 1
- on record
On record: Deco Products Company (Decorah). Most users are in automotive, metal and equipment manufacturing.
Unlock the details behind these industrial users
Discharge flow, federal category, source documents and contacts for every industrial user of Decorah City Of STP. Free with a Klarifi account.
Key contacts
2 verified contacts for Decorah 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 Decorah City Of STP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Iowa
Decorah · 2 mi away
0.0067 MGD
Calmar · 10 mi away
0.14 MGD
Ossian · 11 mi away
0.18 MGD
Ridgeway · 12 mi away
0.02 MGD
Spillville · 12 mi away
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Castalia · 13 mi away
—
Fort Atkinson · 13 mi away
—
Waukon · 14 mi away
0.71 MGD
Decorah 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 February 3, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Anaerobic digester · Lift station · all terms