Twin Boroughs STP
Mifflin, PA · Juniata County · Publicly Owned Treatment Works
- Average flow
- 0.3 MGD
- Design flow
- 0.9 MGD
- NPDES permit
- PA0023264
- Effective
- Permit expires
- February 2027
- Population served
- 2,405
- CWNS 2022
Twin Boroughs STP is a publicly owned wastewater treatment works in Mifflin, Juniata County, Pennsylvania treating an average of 0.3 million gallons per day against a permitted design capacity of 0.9 MGD, serving about 2,405 residents. It discharges under NPDES permit PA0023264 (effective), which expires in February 2027, with 2 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
- 2
- Effluent violations
- 2
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
Decision-makers at Twin Boroughs STP.
No verified contacts on file yet
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Nearby wastewater treatment plants in Pennsylvania
Port Royal · 2 mi away
0.05 MGD
Mcalisterville · 8 mi away
0.04 MGD
East Salem · 9 mi away
0.005 MGD
Lewistown · 9 mi away
0.96 MGD
Thompsontown · 9 mi away
0.16 MGD
Mcclure · 11 mi away
0.13 MGD
Reedsville · 12 mi away
0.3 MGD
Millerstown · 14 mi away
0.04 MGD
Twin Boroughs 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 October 2, 2025.