Colfax Wastewater Treatment Plant
501 W Walla Walla Hwy, Colfax, WA 99111 · Whitman County · Publicly Owned Treatment Works
- Average flow
- 0.33 MGD
- Design flow
- 4.2 MGD
- NPDES permit
- WA0020613
- Administratively continued
- Permit expires
- October 2015
- Population served
- 3,257
- CWNS 2022
Colfax Wastewater Treatment Plant is a publicly owned wastewater treatment works in Colfax, Whitman County, Washington treating an average of 0.33 million gallons per day against a permitted design capacity of 4.2 MGD, serving about 3,257 residents. It discharges under NPDES permit WA0020613 (administratively continued), which expires in October 2015, with 4 recorded violations in the last three years.
Treatment technology
2 treatment structures and unit processes identified at Colfax Wastewater Treatment Plant.
Available with a free Klarifi account
See the full treatment train at Colfax Wastewater Treatment Plant: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 4
- Effluent violations
- 3
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
3 verified contacts for Colfax Wastewater Treatment Plant, with validated emails and direct phone numbers.
Unlock 3 verified contacts
Names, validated emails and direct phone numbers for decision-makers at Colfax Wastewater Treatment Plant, plus the full compliance history and discharge data.
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Palouse · 14 mi away
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Endicott · 15 mi away
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Saint John · 17 mi away
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Oakesdale · 17 mi away
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Rosalia · 24 mi away
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Colton · 25 mi away
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Tekoa · 27 mi away
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Colfax Wastewater Treatment Plant: 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 September 11, 2026.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Filter press · FOG · all terms