Gresham WWTP
Portland, OR · Multnomah County · Publicly Owned Treatment Works
- Average flow
- 8.99 MGD
- Design flow
- 15 MGD
- NPDES permit
- OR0026131
- Administratively continued
- Permit expires
- August 2026
- Population served
- 126,805
- CWNS 2022
Gresham WWTP is a publicly owned wastewater treatment works in Portland, Multnomah County, Oregon treating an average of 8.99 million gallons per day against a permitted design capacity of 15 MGD, serving about 126,805 residents. Treatment on site includes clarifiers, biogas silos. It discharges under NPDES permit OR0026131 (administratively continued), which expires in August 2026, with 0 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
- 0
- Effluent violations
- 0
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Capital improvement projects in Portland
Portland's capital improvement plan lists 208 water, sewer and wastewater line items worth $3.8B starting 2023–2029. The largest budgeted items are shown here.
All water and sewer capital projects in Portland →
| Project | Budget | Years |
|---|---|---|
| Bull Run Filtration | $1,021,346,000 | 2025–2029 |
| Bull Run Filtration | $633,880,000 | 2024–2027 |
| Bull Run Pipelines | $301,685,000 | 2025–2029 |
| Bull Run Pipelines | $178,960,000 | 2024–2027 |
| Willamette River Pipe Crossing | $113,560,000 | 2025–2030 |
Full project details — scope, funding source, engineering consultant and the decision-makers behind each project — are available in Klarifi, along with similar wastewater capital projects in other cities.
Key contacts
1 verified contact for Gresham WWTP, with validated emails and direct phone numbers.
Unlock 1 verified contact
Names, validated emails and direct phone numbers for decision-makers at Gresham WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Oregon
Boring · 9 mi away
0.01 MGD
Milwaukie · 13 mi away
1.74 MGD
Lake Oswego · 13 mi away
3.51 MGD
Tigard · 18 mi away
18.4 MGD
Estacada · 18 mi away
0.44 MGD
Canby · 21 mi away
0.99 MGD
Scappoose · 24 mi away
0.67 MGD
Aurora · 27 mi away
0.08 MGD
Gresham 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 July 2, 2025.