1120 SW 5th Ave, Suite 613, Portland, OR 97204
Updated October 16, 2019
Environmental Services – your sewer and storm utility – is designing a project to clean and inspect a section of a force main that pumps sewage from the Guilds Lake Pump Station on the west side of the Willamette River to a receiving station on the east side of the river. Taking this action now will help protect the public and the environment by reducing the possibility of costly breaks, leaks, blockages and sewage releases.
Beginning in November 2020, crews will begin installing the launching station at the Guilds Lake Pump Station. This permanent structure, referred to as a “Pig Launcher,” will allow for future cleanings of the force main. This routine maintenance is crucial to ensuring that our sewer systems are functioning properly. Once the station has been constructed and installed, maintenance crews will then begin sending “pigs” through the pipe. This process is often referred to as “pigging”.
See the graphic below for a description of what a pig is, and how the process works. Completion of the installation, cleaning, and inspection is scheduled for April 2021.
A pig launcher is a small wye section of pipe that is attached to the force main at the pump station that allows maintenance crews to insert a cleaning device – a pig – into the pipe. Force mains are pressurized pipes, and installing this device allows maintenance crews to safely insert a pig, which can be pushed through the pipe with pressurized water. The pigs will discharge at a receiving station on the opposite side of the river.
This process is repeated using varying sizes of pigs. Once the pipe has been cleaned, maintenance crews will send in an inspection device called a Smart Ball through the system. This ball shaped device uses sonar to detect leaks or places where obstructions exist. This is to determine if further cleaning or maintenance is needed.