By Dean Slejko

Water utilities today are faced with critical challenges. Some of these include managing the potential for high visibility disruptions caused by aging infrastructure, handling service delivery requirements that push the limits of available capacity, balancing conservation measures with increasing operating costs, and meeting customer demands for improved service. Rehabilitation and replacement of existing treatment and distribution systems could resolve these issues, but this is a long, expensive process. Implementation of a two-way, fixed network automated metering infrastructure (AMI) system can address these challenges in a more cost-efficient way.

Many water utilities are considering the advantages of these smart metering systems to address the challenges mentioned above. A recent report by Oracle, “Testing the Water: Smart Metering for Water Utilities,” found that 62% of water utility managers identified enabling early leak detection as the most significant benefit of smart meter technology deployment, followed by 35% who said supplying customers with tools to monitor and reduce water use was crucial. Clearly, each drop of water saved, whether through eliminating leaks or reducing consumption, is of prime importance to water utility managers.

Smart metering systems, as personified by two-way, fixed network AMI, have distinct advantages over simple automated meter reading (AMR) solutions. Whereas mature AMR systems typically communicate one way (from meter to utility) with a limited number of transmissions a day, the latest generation of AMI systems now provides a number of new capabilities that give today’s water utility manager the tools to get the most out of their systems.

Until recently, water utilities have not had the tools necessary to collect and analyse meter data to either effectively perform early leak detection or to monitor and reduce water use. Typically, water meters were read no more than once a month, water balances were performed once a year, and customer bills provided only historical (last month’s) usage.

Utilities that have implemented AMR systems have made progress in analysing consumption patterns to help find leaks and reduce customer usage. For example, some utilities now offer consumers the ability to look at current usage by placing daily customer consumption on a web site, which encourages conservation. Some utilities are also using the data they collect to identify leaks based on consumption patterns. But these systems just scratch the surface of what can be done when data from twoway AMI systems is available.

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A two-way, fixed network smart metering system consists of transmitter units connected to each water meter that automatically read meter data and transmit it to the utility. Data management software validates and presents the meter data so utility personnel can monitor system operation, take appropriate actions, and communicate back to customers

TWO-WAY, TIME SYNCHRONISATION IS CRITICAL
The most significant capabilities of today’s AMI systems are two-way communication between meter and utility and the ability to collect hourly, time stamped reads. The combination of these features allows utilities to more easily perform system-wide functions that yield a number of important benefits.

Traditional AMR systems may provide hourly reads, but these reads are taken asynchronously. System clocks are set to different times, so each meter in the system is read at a different time. A fixed network AMI system that uses a time synchronised approach ensures that each system clock is set at the same time. Utilities then can take a network-wide reading at a single moment in time.

With two-way communication and hourly, time-stamped meter readings, water utilities can realise benefits in a number of critical areas. Among these are promoting water conservation, improving customer service, reducing non-revenue water losses, and extending the life of existing infrastructure.

PROMOTING WATER CONSERVATION
In the Oracle report cited above, 76% of water consumers who responded said they are concerned about water conservation. Most believe they could conserve more, and 71% would reduce their usage if they had detailed information on their water consumption to motivate them. Utilities can use analysis of hourly data to enforce conservation measures such as water use restriction rules. Water usage information also can be sent directly to customers so they can make real-time decisions, encouraging conservation.

IMPROVING CUSTOMER SERVICE
While automatic collection of meter readings allows utilities to bill more accurately, hourly readings can help utilities increase outreach and deliver more personalised service to their customers. For example, instead of waiting until a customer calls to inquire about a high water bill, hourly data could be analysed to identify customers whose usage patterns might indicate continuous consumption. A postcard, e-mail, or phone call to the customer would prompt them to check for leaks within their home or business.

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In typical automated meter reading networks system clocks vary, while in a time-synchronised network all system clocks are set at the same time and a system-wide reading can be taken of all meters at a single point in time. The data collected from this read can be used to simplify system reconciliation

REDUCING NON REVENUE WATER LOSS
Time synchronisation provides utilities with the ability to perform system-wide reconciliation to more easily compare how much water flowing into the system is actually getting to customers. Typically, water utilities only perform a system balance by reviewing the last year’s worth of data. By offering an accurate, time-synchronised snapshot of the entire water system, the latest fixed network AMI systems make the process of balancing and reconciliation easier and more efficient.

Regular system balancing has a number of benefits. Most notable is the ability to identify areas of possible system leaks prior to a major main break or other service disruption. Using time synchronisation, utilities can isolate areas of the system that may have leaks, and determine whether these are occurring before or after the water meter. Once the data is analysed, utilities can take additional measures such as employing acoustic leak detection to accurately pinpoint the location of the leak, or check specific accounts where abnormal consumption is occurring due to tampering or other problems.

EXTENDING THE LIFE OF EXISTING INFRASTRUCTURE
Every unit of water that is saved as a result of improved billing accuracy, conservation, or reduced leakage helps prolong the life of existing infrastructure. In its 2009 Report Card for America’s Infrastructure, the American Society of Civil Engineers estimates that the nation’s drinking water systems face an annual funding shortfall of at least $11 billion to replace aging infrastructure and to comply with existing and future federal water regulations. This trend is complicated by geographic shifts in population, requiring system expansion in areas of high growth, and maintenance of aging systems in areas of diminishing populations with correspondingly smaller rate bases. While many water systems are approaching the end of their useful life (with some pipes well past their useful life), the difficult economic climate suggests that the funding required for costly infrastructure improvements will be difficult to obtain.

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Features, functions and benefits of AMI systems

CONCLUSION
Water utilities can realise significant benefits by deploying fixed network AMI systems with two-way, time synchronised communication. Providing real-time information directly to customers gives them the ability and incentive to make conservation decisions. Communicating with customers also can help to identify potential leaks after the meter, saving customers the expense of unused water as well as potential property damage. Time synchronisation of meter readings allows for regular water system balances, enabling early leak detection before a major disruption occurs. Finally, implementation of AMI systems can help extend the life of existing infrastructure before the need and expense of rehabilitation or replacement. With the critical challenges facing water utilities today, the latest generation of AMI systems can help get every last drop out of your existing infrastructure.