Sewickley STP
Herminie, PA · Westmoreland County · Publicly Owned Treatment Works
- Average flow
- 0.13 MGD
- Design flow
- 0.44 MGD
- NPDES permit
- PA0219142
- Expired
- Permit expires
- April 2026
- Population served
- —
- CWNS 2022
Sewickley STP is a publicly owned wastewater treatment works in Herminie, Westmoreland County, Pennsylvania treating an average of 0.13 million gallons per day against a permitted design capacity of 0.44 MGD. It discharges under NPDES permit PA0219142 (expired), which expires in April 2026, with 0 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 0
- Effluent violations
- 0
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
Decision-makers at Sewickley STP.
No verified contacts on file yet
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Nearby wastewater treatment plants in Pennsylvania
Sewickley · 3 mi away
0.002 MGD
West Newton · 3 mi away
0.67 MGD
N Huntingdon · 3 mi away
1.42 MGD
Coulters · 4 mi away
0.01 MGD
Smithton · 5 mi away
0.0053 MGD
Irwin · 6 mi away
2.4 MGD
Smithton · 7 mi away
0.03 MGD
Elizabeth · 7 mi away
0.57 MGD
Sewickley 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 September 11, 2026; facility record last updated November 27, 2025.