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Tryon Creek Wastewater Treatment Plant Project

Project Background

The City is seeking a new, more efficient wastewater treatment plant to replace the existing Tryon Creek Wastewater Treatment Plant (TCWTP), which needs significant investments to meet necessary DEQ requirements.

The existing plant, strategically located at the confluence of Tryon Creek and the Willamette River, was constructed in 1964 and expanded in 1976. The plant is owned by the City of Portland and operated by the Portland Bureau of Environmental Services. Currently, wastewater treatment operations and maintenance costs are split between Portland and Lake Oswego. The aging plant is in need of a major upgrade or replacement. 

The City is looking to partner with a private partner under a Public-Private Partnership (P3) to minimize the City’s risks and costs, as well as transfer the ownership of TCWTP from the City of Portland to the City of Lake Oswego. 

On December 18, 2018, the City Council approved Resolution 18‐55 authorizing the City to initiate a competitive procurement to enter into a Design ‐ Build ‐ Finance ‐ Operate ‐ Maintain agreement for a new wastewater treatment plant. The City intends to deliver a new wastewater treatment plant, which will replace the aging Tryon Creek Wastewater Treatment Plant. 

The City’s goals of the project are:

Keep costs at a level equal to or below the cost of upgrading the TCWTP

  • Optimize risk transfer to the private developer
  • Obtain a reliable plant design that is more compact, requires a smaller footprint, and would be a better neighbor to the existing and future development through odor control and a more visually appealing design
  • Achieve the earliest date of operations that is consistent with reliable, high‐quality design and construction
  • Achieve reliable operations and effective maintenance
  • Minimize life cycle costs, consistent with the above objectives

The option of a new facility would require a smaller overall footprint and elevate the cities’ environmental commitment by increasing the amount of water treated to newly prescribed waste standards and returned to the river to the natural water cycle. It would also be a good neighbor to the existing and future waterfront development through odor control and a visually appealing design.

The City of Portland and the City of Lake Oswego Councils have approved the establishment of an interim intergovernmental agreement to continue the project. The City of Lake Oswego has hired Illuminati Infrastructure Advisors, LLC, Corrollo Engineers, Inc., and Hawkins Delafield, LLP to advise on this innovative.   

The contracting process as developed by staff provides multiple opportunities for the City to decide whether the Public-Private Partnership is a viable option or not, including multiple checkpoints with Council. The City will continue to weigh out the cost for redevelopment versus the necessary upgrades of the existing plant.