Tryon Creek Wastewater Treatment Plant Project

The City of Lake Oswego is seeking a new and more efficient wastewater treatment plant to replace the existing Tryon Creek Wastewater Treatment Plant (TCWTP) located in Lake Oswego, Oregon.

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 (BES). Currently, wastewater treatment operations and maintenance costs are split between Portland and Lake Oswego. The plant treats an average daily flow of 5.7 Million Gallons per Day (MGD) and can accommodate peak flows up to 37.5 MGD. 

In 2014, BES completed the TCWTP facilities planning process that identified current and future capital improvements to the plant required to ensure the plant continues to meet BES levels of service and regulatory requirements for the next 30 years. The plant is aging and must be upgraded over time to meet increasingly stricter treatment standards and to become more efficient at managing existing wastewater concerns.

During this same period, the City of Lake Oswego was developing and refining its Foothills Framework Plan, which calls for the redevelopment of the Foothills Park Foothills District. This 107‐acre district provides a unique opportunity to connect downtown with its public waterfront, however, the Tryon Creek Wastewater Treatment Plant occupies approximately 13 acres of this redevelopment zone. This led the City to begin considering the design and construction of an alternative replacement plant that would fully enclose the treatment plant area, reduce the facility’s overall footprint from the projected expansion to 15 acres to a smaller footprint, possibly around 4 acres (depending on technology, cost, and site characteristics) and result in higher water quality that is discharged into the Willamette River. This approach potentially would allow for the City to commercially redevelop the Foothills area, while still providing for Portland’s and the City’s wastewater treatment needs.

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 primary objectives in delivering the Project are to:

  • Keep costs at a level equal to or below the cost of upgrading the TCWTP
  • Maximize financial stewardship by deferring the upfront financial outlays associated with the Project, instead tying payments to performance over the life cycle of the replacement Plant
  • Optimize risk transfer to the private developer
  • Obtain a reliable plant design that is more compact, requiring a smaller footprint, and that 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 and high‐quality design and construction
  • Achieve reliable operations and effective maintenance; and
  • Minimize life cycle costs, consistent with the above objectives.

The City encourages consideration of small and local businesses. More details are provided in the Request for Qualifications (RFQ).

For the official RFQ posting, visit the City of Lake Oswego Bid Management System

Questions for the RFQ from applicants are to be directed to the Bid Management site. Questions and answers will be published publicly on the site. 

The City is still exploring this option overall. The City will be weighing out the cost for redevelopment versus the necessary upgrades of the existing plant. This will be a determining factor of whether the City will continue to pursue the Project or not.