Water Loss Management Key to Water Conservation
Mark Patience Jun 08, 2011
In some countries, the potable water resources are so scarce that they are only permitted to pump water for short periods of time each day. In the United States, we are fortunate to have a good supply of fresh drinking water. However, this will not be the case in years to come if we do not address the many issues surrounding our aging water infrastructure. Many of us are unaware just how precious water is and will become in the future.
The American Society of Civil Engineers estimates that 7 billion gallons of water go unaccounted for every day in the United States alone. This can be attributed, in part, to the accuracy of the water meters in older systems. But, more commonly, a good portion of this unaccounted for water is the result of leaking pipes and aging infrastructure.
Although water is abundant and relatively cheap to produce in some areas, if small leaks go unrepaired they can erupt into catastrophic events that cost a considerable amount of time and money to repair. Additionally, as the unaccounted for water increases, it forces utilities to consider expanding their treatment facilities to increase their pumping capacity. This is a large investment that the utility could avoid by reducing the amount of water produced that is not being used. In order to gain control of unaccounted for water and prevent these catastrophic events and additional expenses, utilities need to be more proactive in their approaches to water loss management.
The current most common method of detecting leaks is the leak audit. Utilities hire contractors on a monthly or quarterly basis to perform leak audits. The contractor can only cover small sections of the entire system at a time, and in many cases it may take several years to cover the entire system.
While contractors may very well find leaks during the audit – allowing the utility to recover some of its unaccounted for water – they are only looking at a small portion of the system. This does not solve the problem as the utility simply maintains its current level of unaccounted for water. As a result, utilities are looking for a better, more efficient way to monitor unaccounted for water. Utilities need water loss management programs that cover the entire system and can be monitored more frequently in order get a better understanding of their distribution system.
While the water loss management market is still emerging, we are starting to see an upward trend of utilities moving toward system-wide water loss detection. Some state governments are even beginning to require that utilities show the presence of a water loss management program in order to qualify for state funding. This has helped push the development of new technology to meet the needs of the utility.
Automated meter reading (AMR) and advanced metering infrastructure (AMI) systems offer an easy way to get full system coverage and more frequent data to analyze the distribution system. By attaching an acoustic sensor to the AMR or AMI endpoint, the utility is able monitor its distribution system along with customer service lines to get complete system coverage. The acoustic sensor monitors pipe conditions, looking for changes in the sound that travels down the pipe. The sensor has been designed to listen for a certain frequency range that represents the frequency a leak would produce. By tying the leak sensor to the AMR or AMI system, the utility is able to get a snapshot of its system as often as it reads its meters. In an AMR system, the utility typically receives data on a monthly basis. While in an AMI system, data is received daily.
The AMR or AMI endpoint is also able to monitor the customer’s usage, looking for abnormal patterns of usage that might be the result of a leak in the home. As the endpoint monitors the customer side for leaks and the acoustic leak sensor monitors the distribution side for leaks, utilities get complete coverage of the system. Now the utility is able to monitor its system more frequently and thoroughly, giving it the ability to be truly proactive in finding and repairing leaks.
The Future of Water Loss Management
To take things a step further, utilities are now looking at ways to tie in their water loss management systems to their GIS systems. This allows the utility to track the location of leak sensors and repaired leaks in one system. Over time this will create an extensive database that will allow the utility keep track of repairs made to distribution lines and begin to schedule line replacement.
Utilities are constantly looking for ways to become more efficient with their resources. Water demand is only going to increase as we begin to develop more areas of the country and the world. A true water loss management program allows the utility to be proactive in its repair process and line replacement program and to be great stewards of our water resources.
Mark Patience is Product Manager for water later loss management at Itron. He currently serves on the AWWA Water Loss Management Committee and has extensive experience in water metering, AMR/AMI and water loss management systems.