The valve turning and hydrant flushing program was designed to serve a multitude of needs. Underground infrastructure is very difficult and costly to replace, developing programs that can help extend the life cycle of underground infrastructure saves ratepayers a great deal of money over time. Every week members of the water distribution team head into the field with our Bluetooth-operated valve turning truck and trailer to perform preventative maintenance on many of the city's 5000+ water valves and 1900+ fire hydrants. While turning valves and flushing hydrants, staff cross-references our GIS database to ensure that all of our infrastructure mapping is up to date and accurate.
(Valve turning staff uses GIS mapping and a computerized maintenance management system to improve efficiency)
The valve turning trailer is outfitted with a high powered vacuum that allows our staff vacuum dirt and other debris from the operating nut on a valve, allowing for immediate access to valves in case of emergencies and for scheduled preventative maintenance. Once we have access to the operating nut of a valve the trailer exercises the valve, breaking away any corrosion and tuberculation that may exist on the seat of the valve. By breaking up this tuberculation we are able to get valves to completely seal, allowing us to minimize the amount of water lost during construction or water main leaks. Performing valve exercising extends the effective life cycle of isolation and control valves in our distribution system.
Valve exercising and hydrant flushing go hand-in-hand. As tuberculation is broken up from the seat of the valve, hydrants are opened and flowed, cleaning the seat of the valve, allowing for a smooth surface to seal on. Hydrant flushing also helps expel stagnant water from dead end hydrant laterals, minimizing the risk of bacteriological growth within our water system. Hydrant flushing is a necessary task to maintain high water quality within our distribution system. While it often appears to be wasteful those who witness it while driving or walking by, hydrant flushing is an industry standard and is required to keep our water supply safe and chlorinated.
The opportunity to confirm the accuracy of our GIS mapping allows us to develop more comprehensive and accurate mapping and infrastructure databases. The valve turning crew is tasked with making updates to our mapping system so it accurately represents the infrastructure that lays beneath the earth's surface. An accurate mapping system is essential for decision making not only during emergencies but also for long range planning. Information about water mains, hydrants, and valves, are all updated during the valve turning process, ensuring that we have all of the right information during our decision making processes.