Water Environment Services

Water Environment Services

Tri-City Water Resource Recovery Facility Outfall Project

Latest Updates to Clack-A-Mole and the Tri-City Water Resource Recovery Facility Outfall Project

What is an Outfall?

Every day, Clackamas Water Environment Services (WES) cleans more than 10 million gallons of wastewater at its Tri-City Water Resource Recovery Facility in Oregon City. The treated water, called "effluent," is then sent back to the Willamette River. An outfall is the discharge point where the treated water flows into the river.

Cross-section of outfall project

An outfall is designed to maximize mixing and dilution of effluent. The mixing must meet state water quality standards for boating, swimming, fishing, and aquatic resources.

Project Overview

Background

Map of project areaThe current outfall from the Tri-City facility was constructed in 1984 and is nearing capacity during peak wet weather events. In May 2019, the Clackamas County Board of County Commissioners approved an additional Outfall Project, which would be large enough to provide service for decades to come.

The existing outfall is structurally sound and will remain in place for use if needed. The new outfall will use gravity to convey the water from the treatment facility, so it will not require energy to pump water.

Location

The new outfall will run from the Tri-City facility parallel to I-205 and under the OR 99E off ramp. It will continue under Jon Storm Park and discharge into the Willamette River just north of the I-205 Abernethy Bridge. The Oregon City Charter calls for a vote of the people regarding the easements and for the construction of permanent structures unrelated to park use. In November of 2020, Oregon City voters authorized WES to place the wastewater pipeline underground in Jon Storm Park.

Project Planning

The outfall pipeline will tunnel beneath Jon Storm Park. Construction crews will adhere to the Oregon Department of Fish and Wildlife's Willamette River in-water work requirements. The in-water work guidelines were created to minimize potential impacts to fish, Pacific lamprey, wildlife and habitat resources. In addition, WES' consultants are performing an archaeological investigation and working in compliance with the National Historic Preservation Act. WES is also working with the Confederated Tribes of Grand Ronde Tribal Historic Preservation Office.

Construction will use a design-build process, where the design engineers and builders work together under a single contract from the beginning of the project. This method ensures the project stays on schedule and on budget. 

Funding

The project, which has a construction cost of $58,444,000 will be funded as part of WES' Capital Improvement Plan.

Videos

2025 overview of the Tri-City Water Resource Recovery Facility Outfall Project.

On February 21, a groundbreaking event was held for construction of the new outfall.

On January 23, 2024, the project team held a meeting to update community on the project and answer questions.

Learn more about the project.

Frequently Asked Questions

133806

Resources

Archaeological Information

Clackamas Water Environment Services consultants are performing an archeological investigation and working in compliance with the National Historic Preservation Act (NHPA). WES is also working with the Confederated Tribes of Grand Ronde Tribal Historic Preservation Office. The project will be done with a federal nexus through the U.S. Army Corps of Engineers, and compliance with the NHPA.

The slide below outlines the general strategy WES will follow to ensure that, through consultation and iterative project design, potential impacts to significant cultural resources will be accounted for and addressed prior to construction.

WES Archaeology Project Steps slide 

Routing Study

Archived Materials

Ballot Measure

News and Media

Meeting Materials

Virtual Open House

WES hosted two virtual open house presentations, on August 26, 2020 and September 21, 2020. View the presentation.

Sidebar Heading
Related Information
New Format?
On

Kellogg Creek Bioblitz

Help document the plants, birds, insects, and other wildlife that are currently present in and around the soon to be restored Kellogg Creek!

The Kellogg Creek Bioblitz is an important part of the ongoing efforts to monitor conditions in the natural areas surrounding the Kellogg Creek Impoundment before the Kellogg Creek Restoration and Community Enhancement Project goes to construction in 2026-27. Right now, we want to collect as much data as we can about what plants and animals are currently using this space, and you can help!

Windswept Waters Stewardship

Your help is needed to mulch hundreds of native trees and shrubs that were planted this past winter at this poplar gem of a park! We may also take out some weedy introduced plants, if time allows. This is physically-demanding work (great for folks looking for a work out!).  

Register

Clackamas Water Environment Services is proud to support events like this that help protect water quality.