St Marys City WWTP
Saint Marys, OH · Auglaize County · Publicly Owned Treatment Works
- Average flow
- 1.12 MGD
- Design flow
- 3 MGD
- NPDES permit
- OH0021415
- Effective
- Permit expires
- April 2030
- Population served
- 11,837
- CWNS 2022
St Marys City WWTP is a publicly owned wastewater treatment works in Saint Marys, Auglaize County, Ohio treating an average of 1.12 million gallons per day against a permitted design capacity of 3 MGD, serving about 11,837 residents. Treatment on site includes clarifiers, uncovered lagoons, carrousels / oxidation ditches. It discharges under NPDES permit OH0021415 (effective), which expires in April 2030, with 15 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Clarifiers
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Uncovered lagoons
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Carrousels / oxidation ditches
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Compliance snapshot (last 3 years)
- Total violations
- 15
- Effluent violations
- 9
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
2 verified contacts for St Marys City WWTP, with validated emails and direct phone numbers.
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Names, validated emails and direct phone numbers for decision-makers at St Marys City WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Ohio
St. Marys · 2 mi away
0.0018 MGD
New Knoxville · 4 mi away
0.0014 MGD
New Knoxville · 6 mi away
—
Wapakoneta · 6 mi away
0.0022 MGD
New Bremen · 7 mi away
0.48 MGD
Wapakoneta · 9 mi away
0.0033 MGD
Celina · 10 mi away
—
Wapakoneta · 10 mi away
2.84 MGD
St Marys City WWTP: 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 May 24, 2025.