Ontario utility demonstrates advantages of monitoring distribution system at PRV vaults
The city of Barrie, Ontario, Canada, water operations branch services approximately 147,000 customers. The water operations consist of a single low-lift pumping station that supplies a surface water treatment plant, as well as a network of several groundwater wells, in-ground storage facilities, booster stations and elevated storage tanks. As with most water systems, its focus has been on gathering monitoring and alarm data from these major operations points. However, the water is pumped through miles of water distribution piping, often with little or no consistent monitoring of the overall system health.
Over the last few years, the City of Barrie has been adding monitoring to several locations in the system using the cloud-based SCADA system from High Tide Technologies. This system enables the water operations team to get a good idea of the overall condition of the entire distribution system. The most advantageous place to measure pressures and flows has been at pressure-reducing valve (PRV) chambers; the reason for this is that the PRV is located at the border of two pressure zones. By placing a pressure transmitter on each side of the valve, the operations personnel can monitor the pressures in each zone. These chambers are also usually roomy enough to accommodate some extra equipment.
The installations are quite simple. Insertion flowmeters can be installed into some brands of PRVs. These flowmeters require no changes to existing piping and will provide flow data suitable for analysis of system health. Many times, these chambers will not have power. If that is the case, power generators that will use the water flowing through the piping, along with the pressure drop, to generate electric power are available. This is not a significant amount of electric power, but it is enough to run instrumentation and the High Tide Technologies remote terminal unit (RTU).
The inside of the PRV chamber with the High Tide Technologies RTU.
The City of Barrie has nine PRV chambers using High Tide Technologies RTUs. Eight of the chambers have power supplied to them; one uses the power generator described above. For more than three years, the power generator, the High Tide telemetry unit and the instruments have been providing data and alarms to the Barrie operators. This information allows them to better understand their system, ensure that it is working properly and respond to unusual occurrences quickly.
“High Tide telemetry units allow us to collect data and to alarm our system in locations where we would otherwise have no monitoring capabilities,” said Dave Truax, supervisor of ground water supply for the City of Barrie. “Traditional SCADA is expensive to install and to maintain, but High Tide units provide us with many of the benefits of SCADA at a much lower cost. The units have proven themselves to be reliable and we have improved our system performance thanks to the information supplied by High Tide’s system. One of the biggest advantages is their ease of installation – it is virtually plug and play. Just about anyone can install them without the need of extensive training.”
Because the High Tide Technologies system is a cloud-based system, the operations staff has access via a secure portal from any internet-connected device. Through this portal, they can look at a snapshot of system status or drill down and look at trends for pressures and flow rates.
The advantages of this system are extensive. The operators receive alarms when pressures or flow rates are out of range; these alert them to possible leaks. They can look at trends to see if the system is functioning correctly and if the PRVs are set appropriately for that particular time of year. Also, they do not have to physically visit the valve vaults, which is especially helpful in the cold winter months.
David Mundie, Ph.D., is president of High Tide Technologies.