GENERAL INFORMATION: 503-823-7404
1120 SW Fifth Ave, Suite 600, Portland, OR 97204
Members of the Water Bureau’s Operations Group have been busy conducting upgrades to the water supply system in the Bull Run watershed as well as to the huge conduits that carry water 22 miles to Powell Butte. These upgrades allow the Water Bureau to not only improve water quality protection methods, but also to ensure that the city’s water continues to meet or exceed all federal and state requirements for a public water system utilizing an unfiltered surface water source.
Conduit Vault Replacements
Water Bureau crews at the Sandy River Station are replacing old air valve vaults along the conduits. The air valves are fitted at the highest point on the conduits to continually release unwanted air during water system operation. This release protects the water system against air-related surges, and maintains system efficiency. The outdated vaults are too small to allow workers to test or replace the air valves, and do not adequately protect the air valves from contamination by flood water.
The crews’ goal is to remove and replace all the vaults that are not up to current standards. Sandy River Station staff has replaced about 14 vaults on Conduits 2 and 3 in the last year. Most of the vaults on Conduit 2 are in poor condition. The goal is to replace the remainder of them by the end of this year.
Later this spring, staff from the Water Bureau's Engineering Services Group is planning a shutdown on Conduit 2 east of SE 162nd Avenue. During that shutdown, Sandy River Station staff will replace all the isolation gates and air valves that no longer work correctly. The larger vaults will make this work possible.
Conduit 2 air valve vault, built with red bricks circa 1911, measured about 2-feet in diameter.
Sandy River Station staff installs a new air valve vault on Conduit 2.
Flow Meters Installation
Six new flow meters on the conduits at the Headworks facility in the Bull Run watershed are currently being installed. The new flow meters will replace existing meters installed in the 1920’s through 1950’s. New flow meters will be installed on each of the three conduits leaving Screenhouse #3, and on each of the three conduits leaving the Primary Intake Structure. Three new control valves will also be installed on the conduits leaving Screenhouse #3 to provide full pipe conditions for the flow meters and allow automation of flow control by the water treatment operators at Headworks.
Accurate flow measurement is a critical component in calculating the chlorine feed rate for disinfection, and the monitoring of chlorine contact time to meet regulatory requirements. The new flow meters will result in more accurate chlorine dose control and allow for automated chlorine dose control in the future when new chlorinators are installed.
Flow meters inside water conduit during installation.
The work involves installation of the six new meters, three control valves, and associated piping, electrical, and instrumentation on the water conduits at Headworks.