Monthly Archives: October 2020

Saving Water Through Better Metering

Automated water meter reading devices

Since adopting its Sustainability Plan in 2013, CSUN has achieved a 28% decrease in annual water consumption. This has been done through a variety of different strategies, which include the replacement of water-intensive lawns with drought-tolerant plants, the injection of algae-based hydrogels into the root zone of fields and lawns to improve water retention, efficient irrigation systems, and the replacement of water faucets and fixtures with low-flow alternatives. CSUN’s newest water conservation initiative uses data analytics to detect leaks, inform optimized equipment schedules, and identify opportunities to capture further savings.

Only about one-fourth of CSUN’s buildings have their own water meter, and these are typically read manually once per month. While this practice is useful for tracking overall usage, it does not reveal water usage trends that occur on a smaller time scale such as days, or even hours. CSUN’s new “smart” water meters connect directly to the existing meter, as well as to an online portal, where once a day they report readings taken every five minutes in the past 24 hours. The Energy and Sustainability team can then log into the portal, and view or download data for any time period. The system also has the capability to send email alerts when a specified usage rate is exceeded, meaning that water leaks can be reported in real-time.

One of these automated meter reading devices was installed in July 2019 on the water main that feeds the USU, with the Sierra Center, Arbor Court, and The Soraya receiving similar devices in July of this year.

CSUN’s Manager of Energy & Utilities, Coleen Barsley, led the effort to integrate these devices, and has already managed to detect and stop one significant issue so far. Establishing normal usage thresholds has been challenging because the campus has not seen normal water usage since transitioning to telecommuting and virtual learning in March of 2020. However, Coleen regularly monitors the online portal to manually identify excessive usage. In doing so, she noticed that one facility was experiencing unusually high flow rates for a period of about twenty hours. Unfortunately, the first time this happened was on a Friday, and it wasn’t noticed until the following Monday. The high usage occurred again two more times after that, but stopped before the source could be identified. The fifth time it happened, the facility manager was quickly notified, and they were able to locate a faulty toilet within the facility that was flushing continuously. By identifying and correcting this issue, facility managers were able to prevent between 35,000-40,000 gallons of water from being wasted for each time it might have occurred again. The data from these instances is visualized in the graph below, with the periods of high usage being very easily identifiable. The second image shows data from a normal consumption period.

Water meter data showing periods of abnormally high water usage
Water meter data showing normal water usage

The devices cost around $300 each plus installation, and they have already prevented over $1,000 in water losses while also providing detailed insights into the water usage patterns of various facilities. The Energy & Sustainability team is also working to establish alert thresholds so that future instances of high water usage will be automatically reported shortly after they begin, enabling them to be identified and fixed more quickly. CSUN’s Sustainability team expects to see them become the new standard for campus water meters going forward.