Frequently Asked Questions

Project Need and Background

Why is the new wastewater treatment facility needed?
  • The existing Tryon Creek Wastewater Treatment Plant (TCWTP) was built in 1964 and is owned and operated by the Portland Bureau of Environmental Services (BES). It 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.

What are the main project benefits?

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

Project Status, Delivery Method, and Schedule

What is the status of the process for delivering the new wastewater treatment facility? 
  • The first phase of the project was completed in late 2023, which included developing facility designs, preliminary permitting, and proposed pricing for the Wastewater Treatment Facility Project.
  • In 2024, the project team evaluated competitive procurement delivery methods using public financing for implementing the next phase of the project, which will involve completing the designs, constructing the facility, and operating and maintaining the facility under a long-term contract. This is known as a design-build-operate-maintain (DBOM) delivery method.
What are the next steps? 
  • The next steps include preparing and advertising a Request for Qualifications, followed by a Request for Proposals from qualified firms to engage an entity to finalize designs, construct the new facility, and operate and maintain it. This is expected to take place in the last half of 2024.
Why did Lake Oswego change the project delivery approach at the end of phase 1? 
  • The progressive phased approach was intentionally designed to allow Lake Oswego to determine whether it would be getting the best possible value for ratepayers and customers from a design-build-operate-finance-maintain (DBFOM) private-public partnership, or if there is value in engaging other entities through a competitive method, with public financing.
  • The proposed cost of the private financing provided by EPCOR posed significant cost burdens on ratepayers and customers, compared to public financing. Therefore, it was not financially beneficial to enter phase 2 with EPCOR.
  • The cities believe it will be more cost-effective and a long-term benefit for ratepayers for the next phase of the project to take place using 100% public financing, as opposed to the public-private partnership DBFOM approach.
What did the first phase achieve? 
  • The first phase successfully demonstrated the feasibility of building a new plant away from the riverfront. It also enabled the cities to make a fully-informed decision about the costs and benefits associated with the private-public partnership approach to constructing the project.
Is the project still moving forward? Will you go back to upgrading the old plant, instead of replacing Tryon with a new facility?
  • Yes, the project is still moving forward.
  • There are currently no plans to upgrade the existing Tryon Creek plant, as it has reached the end of its useful life.
  • The cities are committed to replacing the current plant.
  • They still believe it is the best financial decision to build a new, cost-effective, resilient, state-of-the-art facility capable of meeting increasingly stringent regulatory requirements, rather than investing in the outdated plant.
Will you need to redesign the new facility?
  • It is likely there will be some adjustments to the current design, depending on the DBOM entity’s proposed design, construction, and operations approach.
  • We will continue to use the valuable input from residents and stakeholders to finalize the design.
Will AquaNereda technology still be used for the treatment process?
  • The AquaNereda treatment technology is preferred by the cities based on our phase 1 work, due to the site constraints and the environmental sustainability benefits it provides. This preference will be communicated to DBOM entities during the procurement method.
  • However, opportunities will be provided to proposers to offer alternative treatment technologies, as long as they meet the original project goals.
Who will own the new wastewater treatment facility?
  • A change from a DBFOM delivery method to a DBOM delivery method, with public financing, does not affect the ownership of the new facility.
  • The current Tryon Creek Wastewater Treatment Plant (TCWTP) is owned by the City of Portland and operated by the Portland Bureau of Environmental Services.
  • The current plant services Lake Oswego, parts of southwest Portland, and unincorporated areas of Multnomah and Clackamas counties.
  • Lake Oswego contributes more than 50% of sewage to the plant.
  • When the project is complete, Lake Oswego will own the new facility. Portland will be a major customer.
Who will operate the new facility?

As currently planned, the DBOM entity would provide long-term (20+ years) operations, maintenance, repair and replacement services for the new facility.

Finance/Costs

How was the project originally to be financed? Why does the City believe it can get a lower price than that offered by EPCOR?
  • The project was originally scoped to be privately financed, through a combination of a WIFIA loan (for 49% of the project), private debt, and at-risk equity provided by EPCOR.
  • By using lower cost public financing, the City believes that it can significantly reduce the cost burden of the project on ratepayers and the public.
What is the impact of the project qualifying for the federal EPA WIFIA loan during the phase 1 work?
  • The project was selected to apply for a WIFIA loan in December 2021.
  • The low-cost WIFIA loan significantly improves the affordability of the project.
What do you expect the cost of the project will now be?
  • The costs will only be known once the procurement method is finalized and a DBOM proposer is selected.
  • The project team believes that the project can still be implemented within the planned Lake Oswego rate structure of 3.9% increase per year.

Property Acquisition

Are you still acquiring properties for the new facility?
  • Yes, the plan is still to build a new facility next to the existing plant.
  • Lake Oswego has been in the process of acquiring the properties and relocating the impacted businesses since 2021.
  • The site serves a critical community need to supply reliable wastewater services to Lake Oswego and Portland.
Why was this location selected as the preferred site? Were other locations explored for siting the new plant?
  • The site was selected because it is large enough, safer from flooding, and is close to the existing pipes and outfall to the river (thus not requiring re-routing or building new sewer mains to the plant).
  • The new facility needs 6 acres of space and must be in close proximity to the existing Treatment Plant because of the utility infrastructure that is required.  As a result, the only option that meets these needs is to acquire the three properties that are next to the existing plant.
Why can’t the new plant be built on the current site?
  • Consideration was given to building the new facility on the existing Tryon Creek site, however the existing plant needs to be fully operational while the new plant is being built.