Water usage and waste are at record levels as a growing global population, environmental changes and aging water infrastructure strain freshwater resources. Water utilities are adopting the smart grid for water by investing in technologies commonly associated with the smart electric grid. While there are many benefits, the one that offers a significant opportunity for reducing freshwater waste is detecting leaks ? not only in a utility?s infrastructure, but at customer premises.
According to the American Water Works Association (AWWA), the average American household uses 180-250 gallons of water each day and loses 14 percent of that to leakage, and the American Society of Civil Engineers (ASCE) estimates that 7 billion gallons of water are lost each year due to utility infrastructure leaks. Considering these figures, there is a powerful opportunity for water conservation through leak detection.
The smart grid for water facilitates leak detection by delivering hourly usage data from smart water meters to the utility via a two-way communications network.
The utility then analyzes data using specialized software. This data provides insights to support leak detection.
For example, a utility may notice a spike in usage that could indicate a leak, quickly alert the customer to the problem and deploy utility teams for repair. Sensors placed along a utility distribution network can also play a role in identifying pipe leaks.
Building the Business Case
Garden City, Kan., is a municipal utility provider serving the water needs of more than 28,500 residents. In 2008, utility officials began evaluating the need for a fixed-base advanced metering infrastructure (AMI) system that would enable remote meter reading to improve customer service and increase billing accuracy ? accuracy gained in part through leak detection.
For decades, Garden City relied on manual meter reads managed first through the city and subsequently through a contracted meter reading service. Not only was this an additional cost to the city, it was an inconvenience for residents who sometimes complained when meter readers visited their property. Moreover, meter reads were challenging during winter months when snow and ice often prevented readers from accessing the meters, requiring bills to be based on estimated usage.
In addition to benefits including remote meter reading and improved customer service, Garden City sought an AMI system that offered a single solution for electric and water needs to help control project costs and afford greater efficiency in utility operations. After evaluating many different AMI systems, Garden City ultimately chose Sensus and its FlexNet communications network for its smart grid system. The system supported both electric and water needs and covered the entire service territory with only two tower base stations, helping to control costs.
Garden City installed new smart electric meters and up-fitted existing Sensus water meters to cost-effectively support two-way communications. The utility simply switched the registers on existing residential, commercial and industrial meters and installed radio transceivers on each meter to facilitate automated meter reading and a variety of field operations, such as the ability to monitor distribution lines for leaks and provide the ability for future support of home area networks that would provide consumers with detailed data about their usage and associated costs.
Reaping the Benefits
Garden City completed installation of a smart metering infrastructure for its water and electric customers in late 2010 at a total cost of $3.3 million. This investment was financed entirely by the city and officials estimate a full return on investment in the electric program within three years.
While the city is in the earliest stages of gathering data from the water utility, officials have received positive feedback from customers who have benefitted from significant advances in leak detection and notification.
The utility is also using leak detection and flow testing data to identify and fix vulnerabilities throughout the distribution system.
Other benefits of the system were clear from Day 1 as Garden City experienced a significant improvement in its operational efficiency. There were some initial cultural changes required as the utility adjusted back-end processes to manage the marked increase in incoming data from meters. These changes have driven operational improvements as billing staff that previously spent hours correcting billing inaccuracies can now focus energy elsewhere. Customers that previously experienced estimated billing during winter months can now rely on consistent, accurate bills year-round.
Data from meter reads once took three days to be gathered and processed by the billing department. Today, information is gathered in 15-minute intervals and available at a click of the mouse. Billing staff uses this data to address customer billing questions with precise, detailed information that has boosted customer satisfaction.
Customer satisfaction also increased as a result of significant advances in leak detection and notification. The utility is using leak detection and flow testing data to identify and fix vulnerabilities through the distribution system. Leaks that once resulted in costly and wasteful water loss are now discovered and resolved before they damage homes, apartments and businesses.
By prioritizing customers and operational efficiency, Garden City identified the need and opportunity for smart grid for water technologies to benefit the utility and its customers. As industry leaders, consumers and regulators increasingly scrutinize water usage and conservation, the city looks forward to serving as an example for how these technologies can benefit utilities and customers.
Leland D. Cable is Superintendent of Water for the City of Garden City, Kan., with more than 23 years of experience in the water industry, 14 of those in water management. He is a member of American Water Works Association and Water Environment Federation, as well as their state associations.?
