About the Project
The Tryon Creek Wastewater Treatment Plant is aging and in need of major upgrades to continue to reliably meet Oregon Department of Environmental Quality water quality requirements. Lake Oswego, with Portland’s support, is planning to build a new, state-of-the-art wastewater treatment facility to replace the old plant.
Tryon Creek Plant Background
The Tryon Creek Wastewater Treatment Plant (TCWTP) was built in 1964 and is owned and operated by the Portland Bureau of Environmental Service (BES). It is strategically located at the confluence of Tryon Creek and the Willamette River in Lake Oswego. The plant treats wastewater collected from parts of southwest Portland, unincorporated areas of Multnomah and Clackamas counties, and the City of Lake Oswego. Treated wastewater is discharged to the Willamette River via an outfall system.
Currently, wastewater treatment operations and maintenance costs are split between Portland and Lake Oswego. On average, Lake Oswego contributes approximately 70 percent of the flow volume. Lake Oswego also pays approximately 70 percent of the cost of operating the plant, in line with its usage. Both cities are exploring a new plant that would be owned by Lake Oswego.
The existing Tryon Creek Wastewater Treatment Plant is aging and parts of the plant are at the end of their useful life cycle.
The facility needs significant investments to continue to reliably meet current and potentially more stringent Oregon Department of Environmental Quality (ODEQ) permit requirements and protect it against climate change.
Lake Oswego, with Portland’s support, has been using a phased approach that could replace the aging Tryon Creek plant, with an environmentally sustainable wastewater treatment facility, at a good value to the community. The first phase is now complete, which included developing facility designs, preliminary permitting, and proposed pricing for the Wastewater Treatment Facility Project.
A new, state-of-the-art wastewater treatment facility will produce cleaner water and ensure more environmentally sustainable services at a similar cost to upgrading the existing aging facility.
Some additional benefits include:
- Smaller footprint that enables riverfront property to be restored for future use
- Odor control
- More visually appealing design for the neighborhood
- Energy efficient
- Greater climate resiliency
- State-of-the-art water treatment technology
- Higher quality treated water returned to the Willamette River