Seaside WWTP
Seaside, OR · Clatsop County · Publicly Owned Treatment Works
- Average flow
- 1.2 MGD
- Design flow
- 2.25 MGD
- NPDES permit
- OR0020401
- Effective
- Permit expires
- July 2029
- Population served
- 6,875
- CWNS 2022
Seaside WWTP is a publicly owned wastewater treatment works in Seaside, Clatsop County, Oregon treating an average of 1.2 million gallons per day against a permitted design capacity of 2.25 MGD, serving about 6,875 residents. Treatment on site includes clarifiers, aerated lagoons, carrousels / oxidation ditches. It discharges under NPDES permit OR0020401 (effective), which expires in July 2029, with 27 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Compliance snapshot (last 3 years)
- Total violations
- 27
- Effluent violations
- 17
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
Decision-makers at Seaside WWTP.
No verified contacts on file yet
Klarifi verifies plant and municipal decision-makers continuously. Start a free trial to browse contacts at nearby plants and flag this one for verification.
Nearby wastewater treatment plants in Oregon
Cannon Beach · 8 mi away
0.32 MGD
Warrenton · 12 mi away
0.76 MGD
Arch Cape · 14 mi away
0.08 MGD
Astoria · 15 mi away
1.75 MGD
Nehalem · 20 mi away
0.3 MGD
Rockaway Beach · 27 mi away
0.19 MGD
Clatskanie · 28 mi away
0.01 MGD
Rockaway Beach · 29 mi away
0.08 MGD
Seaside 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 September 11, 2026; facility record last updated August 7, 2026.