Water Environment Services

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.

Project Location

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.

Please clean up after your pets!

By 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.
 

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.

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

The 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 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. 

Funding

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.

Videos

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

• Outfall Alternatives Routing Study - Executive Summary 
• Segment 1 Routing Alternatives Evaluation 
• Segments 2A and 2B Routing Alternatives Evaluation 
• Willamette River Outfall Diffuser Siting Alternatives Evaluation 

Archived Materials

Ballot Measure

• Resolution, June 17, 202
• Ballot Measure Language, June 17, 2020
• Measure Explanatory Statement for County Voters' Pamphlet, August 6, 2020

News and Media

• Proposed Ballot Measure Fact Sheet August 2020
• Proposed Ballot Measure - Tri City Water Resource Recovery Outfall Project, August 5, 2020
• Proposed Ballot Measure Questions Answered August 2020

Meeting Materials

• City of Oregon City, City Commission June 17, 2020 - Meeting Agenda and supporting documents, June 17, 2020
• Project presentation to City of Oregon City, City Commission, June 17, 2020

Virtual Open House

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