Water Environment Services

Water Environment Services

Rock Creek Interceptor Extension Project

The Rock Creek Interceptor Extension Project was identified as a priority in the Capital Improvement Master Plan to ensure a safe, resilient, reliable sanitary sewer system with the capacity to serve our community now and in the future. This project will provide additional capacity and system improvements to serve Clackamas County and portions of the Happy Valley, Pleasant Valley, and North Carver Comprehensive Plan area.

Interceptor Defined

An interceptor is a primary sewer line that receives wastewater flow from several smaller trunk and local sewer lines. The interceptor moves the wastewater to the wastewater treatment facility. Interceptors are some of the largest pipes in a sewer system.

Interceptor Defined

An interceptor is a primary sewer line that receives wastewater flow from several smaller trunk and local sewer lines. The interceptor moves the wastewater to the wastewater treatment facility. Interceptors are some of the largest pipes in a sewer system.

Diagram of a water collection system

Project Location

map The work includes extending the Rock Creek Interceptor beyond the intersection of SE 172nd Avenue and SE Troge Road to the north and east: 

  • The north interceptor extension (in red) generally follows the Rock Creek tributary north to the Multnomah County border and includes approximately 9,800 linear feet of new sewer.  
  • The east interceptor extension follows SE Troge Road to SE Foster and includes approximately 3,200 linear feet of new sewer.  

This project is dependent on downstream capacity upgrades being completed under the Clackamas Area Interceptor Improvement Project. See map including downstream projects.

Project Planning

One of the first tasks is to create a baseline of conditions along the pipeline route. Field crews will be surveying land, locating utilities, identifying potential environmental, cultural, and historic resources to protect, and assessing the topography, soil, and geology. Geotechnical borings will also be taken. Property owners will be contacted before access is needed on private property.\

This project is primarily within residential areas. Maintaining access to private properties is essential. We will coordinate with neighbors, local businesses, agencies, and service providers in the area.

This project includes sensitive environmental areas, including Rock Creek, wetlands, and stream crossings. The Rock Creek Extension project will seek to minimize potential impacts to fish and wildlife habitats during design and construction. 

Community members, the WES Advisory Committee, industry experts, and elected officials provided vital input to prioritize this project as part of the Capital Improvement Master Plan.

Frequently Asked Questions

Questions or concerns?
Department Staff
Clackamas Water Environment Services
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Clackamas County offering new option for safe drug disposal

Clackamas County is now offering free Deterra medication disposal pouches to help residents dispose of unused drugs safely. These pouches are available at 20 convenient locations throughout the county.

“When you keep unused drugs in your home, they may be taken by people who shouldn’t take them—including children,” said Dr. Sarah Present, Clackamas County Health Officer. “Using Deterra medication disposal pouches is one way people can help prevent drug misuse and accidental ingestion.”

WES and SOLVE - Waterway Cleanup Series Kickoff Event - Willamette River at Meldrum Bar Park

Join Clackamas Water Environment Services and SOLVE for the kickoff event of the Waterway Cleanup Series. We are looking for volunteers like you dedicated to making a meaningful impact and prevent trash from finding its way into our rivers.  

Please register in advance in order to get a free parking pass. Help us preserve this 85 acre park, over 30% of which is made up of natural vegetation and wetlands. We hope to see you there!

Wastewater leak into the Willamette River

Clackamas Water Environment Services (WES) personnel responded to a release of wastewater near the Willamette River Thursday morning, April 4.

The release came from a break in the sewer line approximately 100 feet back from the riverbank near the 5600 block of River Street in West Linn.

WES personnel are currently doing emergency repairs. A small amount, likely less than a hundred gallons, spilled today.

There is no Poop Fairy

Please clean up after your pets!

Poop fairy signBy the numbers

Clackamas County has almost 100,000 dogs of all shapes and sizes. On average, a dog excretes 0.75 pounds of waste per day. That adds up nearly 13,000 tons of pet waste in our county per year!

Reasons to scoop

  • Dog poop is classified as a pollutant not fertilizer. It can destroy grass.
  • Some dog poop contains harmful diseases.
  • Rain washes dog poop into streams and rivers, where we swim and get our drinking water.
  • Dog poop can be a hazard for other animals as well as people.
  • Cleaning up after your pet is always the right thing to do.

Grab a bag before your next walk, and tell your friends to do the same. Our water will be much healthier.

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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


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.


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 window. 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. 


Construction in the river is currently planned for the in-water work window during July – October of 2024. The project, which has a construction cost of $58,444,000 will be funded as part of WES' Capital Improvement Plan.


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



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.

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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!