Grand Coulee WWTP
Industrial Rd, Grand Coulee, WA 99133 · Grant County · Publicly Owned Treatment Works
- Average flow
- 0.2 MGD
- Design flow
- 0.9 MGD
- NPDES permit
- WA0044857
- Administratively continued
- Permit expires
- December 2014
- Population served
- 2,096
- CWNS 2022
Grand Coulee WWTP is a publicly owned wastewater treatment works in Grand Coulee, Grant County, Washington treating an average of 0.2 million gallons per day against a permitted design capacity of 0.9 MGD, serving about 2,096 residents. It discharges under NPDES permit WA0044857 (administratively continued), which expires in December 2014, with 0 recorded violations in the last three years.
Treatment technology
2 treatment structures and unit processes identified at Grand Coulee WWTP.
Available with a free Klarifi account
See the full treatment train at Grand Coulee 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
Decision-makers at Grand Coulee WWTP.
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Nearby wastewater treatment plants in Washington
Wilbur · 17 mi away
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Bridgeport · 32 mi away
0.15 MGD
Brewster · 38 mi away
0.16 MGD
Okanogan · 39 mi away
0.16 MGD
Omak · 40 mi away
0.54 MGD
Davenport · 44 mi away
0.16 MGD
Odessa · 44 mi away
0.04 MGD
Chelan · 47 mi away
0.75 MGD
Grand Coulee 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 November 29, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · FOG · Equalization tank · all terms