Rainier STP
106 W 6th St, Rainier, OR 97048 · Columbia County · Publicly Owned Treatment Works
- Average flow
- 0.39 MGD
- Design flow
- 0.5 MGD
- NPDES permit
- OR0020389
- Administratively continued
- Permit expires
- July 2017
- Population served
- 1,940
- CWNS 2022
Rainier STP is a publicly owned wastewater treatment works in Rainier, Columbia County, Oregon treating an average of 0.39 million gallons per day against a permitted design capacity of 0.5 MGD, serving about 1,940 residents. It discharges under NPDES permit OR0020389 (administratively continued), which expires in July 2017, with 30 recorded violations in the last three years.
Treatment technology
Treatment structures and unit processes at Rainier STP.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 30
- Effluent violations
- 27
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
Decision-makers at Rainier STP.
No verified contacts on file yet
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Nearby wastewater treatment plants in Oregon
Clatskanie · 13 mi away
0.29 MGD
Vernonia · 20 mi away
0.39 MGD
Clatskanie · 21 mi away
0.04 MGD
Scappoose · 24 mi away
1.02 MGD
Astoria · 40 mi away
4.38 MGD
Portland · 44 mi away
11.55 MGD
Warrenton · 47 mi away
—
Seaside · 47 mi away
1.65 MGD
Rainier 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 October 26, 2026; facility record last updated May 24, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Tertiary treatment · Significant industrial user · all terms