Project Design and Pipeline Route
The first task of this project was to determine the preliminary design and preferred route for the new conveyance pipeline. This step in the process has been in discussion for over a decade and is now complete. All necessary permits and easements have also been obtained. The route of the replacement pipeline is parallel to the existing effluent pipeline. The route will cross private property, the Burlington Northern Santa Fe Railway, existing utility lines, Salmon Creek, Lake River, and two road rights of way.
Improved Outfall Diffuser for Water Quality
As part of our goal of fostering a healthy environment, an improved river discharge assembly, called an outfall diffuser, will be built at the end of the new effluent transmission pipeline. The outfall diffuser will improve Columbia River water quality by better diluting and mixing discharged treated water. Since the Department of Ecology (Ecology) monitors and regulates the health of the Columbia River, we’ve worked closely with Ecology to determine the best location and design for the outfall (discharge location). The mixing zone will meet stringent standards set by Ecology to ensure clean water for swimming, boating, fishing, and aquatic resources.
An improved outfall diffuser will ensure that discharge of treated water is mixed and diluted efficiently and will meet water quality standards.