Winchester WWTP
Joseph Ave, Winchester, ID 83555 · Lewis County · Publicly Owned Treatment Works
- Average flow
- 0.01 MGD
- Design flow
- 0.03 MGD
- NPDES permit
- ID0020184
- Administratively continued
- Permit expires
- September 2025
- Population served
- 288
- CWNS 2022
Winchester WWTP is a publicly owned wastewater treatment works in Winchester, Lewis County, Idaho treating an average of 0.01 million gallons per day against a permitted design capacity of 0.03 MGD, serving about 288 residents. It discharges under NPDES permit ID0020184 (administratively continued), which expires in September 2025, with 72 recorded violations in the last three years. EPA has recorded 3 formal enforcement actions naming the plant, the latest in August 2021.
Treatment technology
Treatment structures and unit processes at Winchester WWTP.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 72
- Effluent violations
- 37
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 Winchester WWTP in EPA's ICIS system.
- Formal actions
- 3
- 2 since FY2020
- Penalties assessed
- $15,000
- all cases
- Compliance actions
- $195,580
- required by EPA orders
- EPA inspections
- 0
- none on record
Latest case · Aug 2021
Winchester, City of
Administrative order · CWA, NPDES Permit Violations · Final Order With Penalty · Penalty $15,000
EPA's description of the case:
“EPA Region 10 reached settlement with the City of Winchester (Respondent), Winchester, ID for CWA Violations. Respondent exceeded effluent limits in their NPDES permit for E.coli, total residual…”
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Source: EPA ECHO, civil enforcement case 10-2021-0119.
Full case history with a free Klarifi account
Every action against Winchester WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
Decision-makers at Winchester WWTP.
No verified contacts on file yet
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Nearby wastewater treatment plants in Idaho
Craigmont · 8 mi away
0.3 MGD
Culdesac · 10 mi away
0.06 MGD
Nezperce · 18 mi away
0.008 MGD
Cottonwood · 20 mi away
0.22 MGD
Orofino · 23 mi away
0.28 MGD
Juliaetta · 23 mi away
0.03 MGD
Lewiston · 23 mi away
3.36 MGD
Orofino · 23 mi away
0.02 MGD
Winchester 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 October 26, 2026; facility record last updated January 23, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Significant industrial user · WWTP · all terms