Masonville, City Of-STP
Gordon St. 1/4 Mile East Of Local St., Masonville, IA 50654 · Delaware County · Publicly Owned Treatment Works
- Average flow
- —
- Design flow
- 0.02 MGD
- NPDES permit
- IA0077241
- Effective
- Permit expires
- August 2029
- Population served
- —
- CWNS 2022
Masonville, City Of-STP is a publicly owned wastewater treatment works in Masonville, Delaware County, Iowa. It discharges under NPDES permit IA0077241 (effective), which expires in August 2029, with 1 recorded violation in the last three years.
Treatment technology
One treatment structure or unit process identified at Masonville, City Of-STP.
Available with a free Klarifi account
See the full treatment train at Masonville, City Of-STP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 1
- Effluent violations
- 1
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 Masonville, City Of-STP, from the plant's pretreatment programme records.
- Industrial users
- 7
- on record
Among them: Ag Processing Incorporated (Mason City); Cargill Kitchen Solutions (Mason City); Church& Dwight CO., INC. (Mason City). Most users are in chemicals, plastics and petroleum and food and beverage.
Industrial users of Masonville, City Of-STP →
Unlock all 7 industrial users of this plant
Discharge flow, federal category, source documents and contacts for every industrial user of Masonville, City Of-STP. Free with a Klarifi account.
Key contacts
Decision-makers at Masonville, City Of-STP.
No verified contacts on file yet
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Nearby wastewater treatment plants in Iowa
Manchester · 7 mi away
0.64 MGD
Dundee · 8 mi away
—
Winthrop · 8 mi away
0.23 MGD
Lamont · 9 mi away
—
Ryan · 10 mi away
—
Quasqueton · 11 mi away
0.03 MGD
Aurora · 12 mi away
—
Delaware · 13 mi away
—
Masonville, 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 · WWTP · Biosolids · all terms