St Clair Pws
Highway N, St. Clair, MO 63077 · Franklin County · Publicly Owned Treatment Works
- Average flow
- 0.75 MGD
- Design flow
- —
- NPDES permit
- MO0099465
- Administratively continued
- Permit expires
- March 2025
- Population served
- 9,455
- CWNS 2022
St Clair Pws is a publicly owned wastewater treatment plant in St. Clair, Franklin County, Missouri treating an average of 0.75 million gallons per day, serving about 9,455 residents. It discharges under NPDES permit MO0099465 (administratively continued), which expires in March 2025, with 19 recorded violations in the last three years. EPA has recorded 2 formal enforcement actions naming the plant, the latest in September 2025.
Treatment technology
4 treatment structures and unit processes identified at St Clair Pws.
Available with a free Klarifi account
See the full treatment train at St Clair Pws: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 19
- Effluent violations
- 15
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
EPA enforcement history
Federal civil enforcement cases, compliance inspections and informal actions recorded for St Clair Pws in EPA's ICIS system.
- Formal actions
- 2
- 1 since FY2020
- Compliance actions
- $10,000
- required by EPA orders
- EPA inspections
- 0
- none on record
Latest case · Sep 2025
St. Clair MO Biosolids ESA
Administrative order · CWA, NPDES Permit Violations · Final Order With Penalty
Source: EPA ECHO, civil enforcement case 07-2025-0100.
Full case history with a free Klarifi account
Every action against St Clair Pws with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
Decision-makers at St Clair Pws.
No verified contacts on file yet
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Nearby wastewater treatment plants in Missouri
Union · 5 mi away
0.0017 MGD
Union · 5 mi away
1.05 MGD
Union · 5 mi away
0.33 MGD
Villa Ridge · 7 mi away
—
Union · 8 mi away
0.02 MGD
Villa Ridge · 8 mi away
0.002 MGD
Villa Ridge · 9 mi away
0.03 MGD
Villa Ridge · 9 mi away
0.002 MGD
St Clair Pws: 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 12, 2026; facility record last updated August 14, 2024.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Biological nutrient removal · Tertiary treatment · all terms