Lewiston WWTP
900 7th Ave N, Lewiston, ID 83501 · Nez Perce County · Publicly Owned Treatment Works
- Average flow
- 3.36 MGD
- Design flow
- 5.7 MGD
- NPDES permit
- ID0022055
- Administratively continued
- Permit expires
- January 2021
- Population served
- 45,845
- CWNS 2022
Lewiston WWTP is a publicly owned wastewater treatment works in Lewiston, Nez Perce County, Idaho treating an average of 3.36 million gallons per day against a permitted design capacity of 5.7 MGD, serving about 45,845 residents. It discharges under NPDES permit ID0022055 (administratively continued), which expires in January 2021, with 0 recorded violations in the last three years.
Treatment technology
3 treatment structures and unit processes identified at Lewiston WWTP.
Available with a free Klarifi account
See the full treatment train at Lewiston WWTP: structures, unit processes and planned upgrades, with exact unit counts.
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
3 verified contacts for Lewiston WWTP, with validated emails and direct phone numbers.
Unlock 3 verified contacts
Names, validated emails and direct phone numbers for decision-makers at Lewiston WWTP, plus the full compliance history and discharge data.
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Genesee · 9 mi away
0.3 MGD
Culdesac · 17 mi away
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Juliaetta · 17 mi away
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Kendrick · 21 mi away
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Moscow · 21 mi away
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Winchester · 23 mi away
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Troy · 24 mi away
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Lewiston 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 March 28, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Significant industrial user · WWTP · all terms