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.
  • Before investing in aging technologies and processes, the cities of Lake Oswego and Portland are exploring whether a new, resilient, and state-of-the-art wastewater treatment facility can be built to replace the aging TCWTP at a cost similar to or less than the costs of upgrading, modifying, and operating the existing facility.
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 AquaNereda® water treatment technology
  • Higher quality treated water returned to the Willamette River

Public-Private Partnerships (P3)

What is the process for delivering the project?

The project is being delivered under a progressive, dual-stage approach. The first phase involves a Preliminary Services Agreement (PSA) with EPCOR Foothills Water Partners (EFWP) for design development, permitting, financial structuring, community engagement etc. The PSA phase allows the cities to make an informed decision about the costs and benefits associated with replacing TCWTP with a new, resilient, state-of-the-art facility.

At the end of the Preliminary Services period, if Lake Oswego and Portland approve moving forward with the project, the second phase will be covered under a Public-Private Partnership (P3) Agreement. The second phase will involve completing the design, construction, and commissioning of the new facility. EFWP will then operate and maintain the facility for the next 30 years according to the P3 agreement.

What is a Public-Private Partnership (P3) and how does it benefit the cities?

Public-Private Partnerships (P3) generally refer to long-term contractual arrangements between a public authority and a private partner for the design, construction, financing, operation and/or maintenance of a public infrastructure facility like the proposed Lake Oswego Wastewater Treatment Facility.

Under the P3 approach for the proposed Lake Oswego Wastewater Treatment Facility,  EFWP assumes a large share of the risks associated with designing, building, financing, operating, and maintaining the wastewater facility. This insulates the public against project risks such as cost-overruns, schedule delays, performance shortfalls, etc.

Why is a progressive dual-stage approach decision process beneficial?

The process minimizes up upfront expenditures until after the replacement wastewater treatment facility is complete. It gives the cities the opportunity to make decisions based on a definitive life cycle cost analysis and its impact on customers.

Is P3 privatization?

No.  P3 is not privatization. The new treatment facility will be 100% owned by the City of Lake Oswego and EFWP will have no title or ownership in the facility.

Has P3 been done anywhere else in Oregon?

The practice of public-private partnerships is used in Oregon for wastewater treatment.  For example, Gresham and The Dalles use private contract operators and Wilsonville is a Design-Build-Operate plant.  Lake Oswego’s use of a progressive design-build-finance-operate-maintain approach is new to Oregon.

Who is EPCOR and what is their expertise?

EPCOR has extensive experience delivering and operating wastewater treatment plants through the P3 arrangements. EPCOR USA is headquartered in Phoenix, Arizona and currently provides water, wastewater, wholesale water and natural gas services to approximately 780,000 people across 42 communities and 18 counties in Arizona, New Mexico, and Texas.

How was EPCOR Foothills Water Partners selected?

EFWP was selected through a competitive procurement process. A selection committee comprising of City of Lake Oswego and City of Portland staff reviewed the proposals and recommended the selection of EPCOR to the Lake Oswego City Council.  City Council reviewed the selection committee’s recommendation and approved a Preliminary Services Agreement (PSA) with EFWP in May 2021.

Is there an off-ramp in the process? What happens if the cities decide not to move forward with the project?

Yes. The Preliminary Services approach to this project ensures that the cities can make a fully informed decision about this project, and they are under no obligation to proceed.  If, for any reason, the cities decide not to move forward, the cities can terminate their agreement with EFWP, compensating EPFWP only for costs incurred to that date.

Future Ownership, Operations and Maintenance

Who will own the new wastewater treatment 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 (BES). TCWTP services Lake Oswego, parts of southwest Portland, and unincorporated areas of Multnomah and Clackamas counties.

When the project is complete, ownership of the new facility will be transferred to Lake Oswego. This will give Lake Oswego more control, while enabling both cities to maintain affordable wastewater treatment services.

Who will operate the new facility?

Lake Oswego will be the owner of the new facility and Portland will be a customer. The cities are planning to partner with EFWP under the P3 agreement to manage ongoing operations and maintenance of the facility. This P3 agreement will be in effect for 30 years.

Foothills Neighborhood Impact

How will the proposed new facility benefit the surrounding Foothills neighborhood?

The proposed new wastewater treatment facility will be significantly more neighbor friendly. The facility will be located on a smaller 6 acre site with treatment processes housed in a fully enclosed building. Benefits for the neighborhood include:

  • Smaller footprint – 6-acre footprint compared to 12 acres to expand the old facility
  • Better neighborhood appeal – design and landscaping will fit into the Foothills neighborhood
  • Reduced odor and emissions – treatment processes will be fully enclosed in a building
  • Reclaimed riverfront – existing property adjacent to Foothills Park will be restored for other potential future uses
Where will the new proposed facility be located?

The proposed site for the new facility is located on the far northwest corner of the Foothills District. A map can be found here. Some of the benefits of this location include:

  • Reduced flood risk
  • Smaller footprint in the neighborhood
  • Ability to restore existing TCWTP riverfront property for other potential future use
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, close to the existing pipes and outfall to the river, and is safer from flooding.

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 purchase the three properties that are next to the existing plant, which totals 6 acres.

Unfortunately, the City of Lake Oswego is fully-built out and there isn’t vacant land nearby that is available to utilize.

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 and it was found that it was not feasible since the existing plant needs to be fully operational while the new plant is being built.

Will property need to be acquired for the project to move forward?

Yes. Lake Oswego is responsible for acquiring easements and property necessary for the project, including working with the property owners and tenants. This process is underway.

Lake Oswego’s interest in exploring the purchasing of the properties is to serve a critical community need to supply reliable wastewater services to Lake Oswego and a portion of Portland.

What will happen to the businesses located on the properties you are proposing to acquire? Will they need to be relocated?

Yes, the City is committed to working with impacted businesses to help with relocation while following all legal process to acquire the land.

In November 2021, Lake Oswego hired Universal Field Services to assist businesses with relocation efforts.

The City will pay fair market value for the land, improvements, and will also pay relocation expenses for any impacted businesses.

Will the City be using eminent domain?

The City will consider a Resolution of Necessity at the December 20 Council Meeting.  The Resolution of Necessity is a formal resolution that describes the land to be acquired and the public interest in acquiring the land.  The Resolution of Necessity is the first step in an eminent domain procedure. The process requires a back-and-forth negotiation with the property owners.

What will happen with the property where the existing facility is located?

The City of Portland currently owns the existing site of the Tryon Creek Wastewater Treatment Plant, which is located within Lake Oswego.  Under the proposed new arrangement, the site will be sold to the City of Lake Oswego for $1.  Once the new facility is complete, Lake Oswego will decommission and demolish the old facility and remediate the land.

After this is complete, the property will be ready for other potential future use. This will be a separate project from the planning, design, and construction of a new wastewater treatment facility.

How much will it cost to remediate the old plant site?

Cost estimates for demolishing and remediating the old plant site are in development.

How will neighbors be kept up to date on the project?  Do neighbors have the opportunity to weigh in?

The City is committed to being a good neighbor and will keep residents and the general public informed and involved throughout every phase of the project. This will involve ongoing community information sessions, public meetings, a dedicated project website, ongoing project updates, and other opportunities to share information and gather feedback. To learn about upcoming opportunities, visit the ‘Get Involved‘ page.

How can I learn more?

For more information or to sign-up for e-news visit You can also contact the project team here.

Affordability and Financing

How much will the new facility cost?

Cost estimates are being developed and refined throughout the design process.

A critical part of the project is to determine the feasibility of constructing and operating a wastewater facility at similar or below the projected cost of upgrading and operating the existing Tryon Creek Wastewater Treatment Plant. This will include a financial analysis to assess if the impacts to customer rates is the same or less than upgrading and continuing to operate the existing plant.

Environmental Sustainability

How will the new facility elevate the cities’ environmental commitment?

The new state‐of‐the‐art facility will have a smaller overall footprint than conventional treatment technologies and elevate the cities’ environmental commitment through

  • Energy savings (40%-50% less than MBR treatment technologies)
  • Minimizing carbon footprint
  • Discharging higher water quality to the Willamette River
How will the new facility address regulatory requirements?

The new facility will meet more stringent treatment standards than the existing TCWTP, producing effluent (liquid wastewater) that exceeds current treatment requirements for discharge to the Willamette River.

What reliability standard will the facility be designed to meet?

The new wastewater treatment facility will be designed  to meet the highest level of reliability (Class I) as required by Oregon DEQ for wastewater treatment facilities within the Willamette Valley.

How will the new facility improve resiliency?

The new facility will be constructed above the floodplain elevation and will be designed to withstand earthquakes.

State-of-the-Art Wastewater Treatment

What kind of technology will be used for the new treatment facility?

AquaNereda® Aerobic Granular Sludge technology was selected for the treatment facility after also evaluating Membrane BioReactor (MBR) technology. It provides tertiary treatment which will further improve wastewater quality before it is discharged to the environment.

Why was AquaNereda Aerobic Granular Sludge technology selected? What are its main benefits over MBR technology?

AquaNereda is an innovative biological wastewater treatment technology with many benefits for Lake Oswego and Portland:

  • Smaller footprint – AquaNereda technology requires less acreage enabling riverfront property to be restored for other potential uses
  • Energy efficient – Energy savings of 40%-50% compared to MBR technology
  • Environmentally friendly – Lower carbon footprint and provides high wastewater quality using less chemicals and energy
  • More efficient maintenance and operations
How does AquaNereda technology work?

Watch this brief video to learn more.

Federal Water Infrastructure Finance and Innovation Act

What is WIFIA?

With the help of Senator Jeff Merkley and others, the Water Infrastructure Finance and Innovation Act (WIFIA) program was created by Congress in 2014 to accelerate investment in water infrastructure projects like the Lake Oswego Wastewater Treatment Facility Project.

The federal credit program helps make critical water infrastructure projects more affordable for communities and their ratepayers. It couples low interest rates with flexible, long-term repayment schedules. This lowers the cost of investment in critical water projects, extending payments over the life of the asset.

Regionally, the Portland Water Bureau, Willamette Water Supply Program, Cascade Groundwater Alliance, and City of Beaverton have all received WIFIA loans, which will save their ratepayers millions of dollars. Other water and wastewater systems in the region are also applying for these loans to take advantage of the savings from the program.

What are the benefits of WIFIA?
  • Low interest rates. The WIFIA program sets its interest rate based on the U.S. Treasury rate on the date of loan closing, the lowest possible borrowing rate in the country. This interest rate is not impacted by the borrower’s credit or loan structure, allowing borrowers to benefit from the AAA Treasure rate, regardless of the project’s credit profile.
  • Customized repayment schedules. Borrowers can customize their repayments to match their anticipated revenues and expenses for the life of the loan. This flexibility provides borrowers with the time they may need to phase in rate adjustments, minimizing the impact of new projects on ratepayers.
  • Long repayment period. WIFIA loans may have a length of up to 35 years after substantial completion of the project, allowing payment amounts to be smaller throughout the life of the loan, thereby minimizing the impact on user rates.
How does the WIFIA application process work?

WIFIA’s application process includes two phases. The first involves project selection, where prospective borrowers submit letters of interest and the EPA selects projects which it intends to fund.

The next stage includes submitting a formal application, where the EPA will then conduct a detailed financial and engineering review of the project, followed by mutually negotiating a loan agreement, and financial close.

If the application is approved, who will take out the loan?

EPCOR Foothills Water Partners Inc. (EPCOR Foothills) would be the loan holder.

What are some of the criteria the EPA uses for selecting projects for the WIFIA program?

EPA selects projects for the WIFIA program on the basis of project impact, creditworthiness and other factors, including protection against extreme weather events and emerging contaminants, use of new or innovative approaches, environmental sustainability, and replacement of aging infrastructure systems.

What makes EPA’s selection of this project to apply for WIFIA funds noteworthy?

The selection of the Lake Oswego Treatment Project to apply for WIFIA funding by EPA is particularly noteworthy because EPCOR Foothills will be the borrower of the loan, as opposed to the City, based on the terms of a design-build-finance-operate-maintain public private partnership agreement.

Is it common for a private corporation to take out a WIFIA loan?

This is the first time that a private partner will be the WIFIA loan applicant, under the design-build-finance-operate-maintain P3 Agreement structure. This is one of the unique and innovative aspects of the project that will make the proposed new wastewater treatment facility more cost-effective for the community.

The practice of public-private partnerships is widely used in Oregon for wastewater treatment. For example, Gresham and The Dalles use private contract operators and Wilsonville is a Design-Build-Operate plant. Lake Oswego’s use of a progressive design-build-finance-operate-maintain approach is new to Oregon.

When will it be announced that the WIFIA loan is approved?

If the application is approved, it is anticipated the WIFIA loan closing with EPCOR Foothills would occur in the third quarter of 2022, after a determination by the cities to proceed with the project.


Where can I get more information about the WIFIA program?

Permitting and Regulatory Processes

What permitting and approval requirements must be met to build the new wastewater treatment facility?

Multiple permits and approvals from federal, state, county and local agencies must be in place prior to construction and operation of the new Lake Oswego Treatment Facility. These permits and approvals ensure the new plant will meet stringent environmental, land use, and operational standards. Because the project is still in the design phase, the summary of requirements presented below are preliminary and may change as design progresses.

Federal Requirements

  • National Environmental Policy Act (NEPA)
  • National Historic Preservation Act (NHPA)
  • American Iron and Steel Requirement
  • Davis-Bacon Wage Requirements
  • Archeological and Historic Preservation Act
  • Environmental Justice
  • Endangered Species Act (ESA)
  • All Civil Rights Acts
  • Clean Water Act (CWA)
  • Clean Air Act
  • Safe Drinking Water Act (SDWA)
  • Coastal Zone Management Act
  • Protection of Wetlands
  • Farmland Protection Policy Act
  • Magnuson-Stevens Fishery Conservation and Management Act
  • Wild and Scenic Rivers Act

US Army Corps of Engineers

  • Removal/Fill Permit
  • Biological Assessment/Essential Fish Habitat/Mitigation
  • Section 106 Compliance

Federal Emergency Management Agency

  • Conditional Letter of Map Revision
  • Final Letter of Map Revision

Oregon Department of Environmental Quality

  • NPDES Wastewater Permit
  • Air Permit
  • 1200-C Construction Stormwater Permit
  • 401 Water Quality Certification

Oregon Department of State Lands

  • Wetland & Ordinary High Water (OHW) Delineation Concurrence
  • Removal/Fill Permit
  • Function and Value Assessment & Mitigation

Clackamas County

  • Lot Consolidation

City of Lake Oswego

  • Land Use & Development Review
  • City Development Code Requirements
  • Landslide Hazard & Erosion Risk Areas Geotechnical Report
  • Flood Management Area
  • Building Permits
  • Erosion Control Permit
  • Tree Protection and/or Tree Removal Permit
  • Street Opening/ROW Permit
  • Temporary Traffic Control Permit

City of Portland

  • Bureau of Development Services Permit

PGE, NW Natural, Other Franchise Utilities

  • Utility Permitting
What is the approach for acquiring permits and approvals to construct the new wastewater treatment facility?

Lake Oswego, Portland, and EPCOR Foothills Water Partners have developed a permitting plan for the project.  It outlines the major steps to obtain permits, land use approvals, code requirements, environmental reviews, and approvals to build and operate the new facility. The plan will be updated at 30% and 60% design phases as designs are refined.

What type of Land Use Review does this project need to go through with the City?

The project will go through the City’s Development Review Commission (DRC) Public Hearing process.  This is a very comprehensive process that includes:

  • Land Use & Development Review
  • City Development Code Requirements
  • Landslide Hazard & Erosion Risk Areas Geotechnical Report
  • Flood Management Area
  • Building Permits
  • Erosion Control Permit
  • Tree Protection and/or Tree Removal Permit
  • Street Opening/ROW Permit
  • Temporary Traffic Control Permit
Why is the project starting the land use and development review permit application before final design and property is acquired?

The project started the land use permitting process in late 2021 because the cities and EPCOR need to understand the land use requirements and wanted to incorporate neighborhood feedback into the design of the facility before the Council makes a decision on moving forward with the project.  

Will there be a neighborhood meeting before the development review application is submitted?

Yes.  This is required as part of the development review application process.  This meeting enables us to share preliminary development plans and get feedback on preliminary designs for the proposed facility from neighbors and the public. This meeting was held via Zoom on February 3, 2022, between 6 and 8 pm.  For neighborhood meeting information click here.

Will there be additional opportunities for input on the design or architectural features?

Yes. The project team plans to apply for a land-use development review application in early 2023. This will involve public hearings at the Development Review Commission meetings. We will share this information on the project website once the application is submitted.

What is the timeline for permitting?

Preliminary work is already underway.  Different permits will have different requirements and schedules.

Project Schedule

What is the project schedule?

Schedules are subject to change

Site investigation and Preliminary Design Summer 2021 – Early Fall 2021
Design Development – through 90% Fall 2021 – Spring/Summer 2023
Permitting Ongoing