Knoxville City Of STP
1703 East Pleasant Street, Knoxville, IA 50138 · Marion County · Publicly Owned Treatment Works
- Average flow
- 1.39 MGD
- Design flow
- 5.42 MGD
- NPDES permit
- IA0035866
- Administratively continued
- Permit expires
- July 2025
- Population served
- 8,080
- CWNS 2022
Knoxville City Of STP is a publicly owned wastewater treatment works in Knoxville, Marion County, Iowa treating an average of 1.39 million gallons per day against a permitted design capacity of 5.42 MGD, serving about 8,080 residents. It discharges under NPDES permit IA0035866 (administratively continued), which expires in July 2025, with 17 recorded violations in the last three years.
Treatment technology
3 treatment structures and unit processes identified at Knoxville City Of STP.
Available with a free Klarifi account
See the full treatment train at Knoxville City Of STP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 17
- Effluent violations
- 17
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 Knoxville City Of STP, from the plant's pretreatment programme records.
- Industrial users
- 1
- on record
On record: 3M (Minnesota Mining & Mfg Co) - Knoxville (Knoxville). Most users are in paper and packaging.
Unlock the details behind these industrial users
Discharge flow, federal category, source documents and contacts for every industrial user of Knoxville City Of STP. Free with a Klarifi account.
Key contacts
5 verified contacts for Knoxville City Of STP, with validated emails and direct phone numbers.
Unlock 5 verified contacts (2 more than shown)
Names, validated emails and direct phone numbers for decision-makers at Knoxville City Of STP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Iowa
Harvey · 8 mi away
—
Pella · 9 mi away
2.36 MGD
Melcher-Dallas · 10 mi away
0.2 MGD
Tracy · 10 mi away
—
Pleasantville · 11 mi away
0.26 MGD
Bussey · 13 mi away
—
Monroe · 14 mi away
0.27 MGD
Leighton · 15 mi away
—
Knoxville 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 August 18, 2026.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Sludge dewatering · Biological nutrient removal · all terms