A smart approach to water leak detection and prevention
By utilising mobile automatic meter reading (AMR) and fixed network advanced metering infrastructure (AMI) systems, utilities in the region can build successful leak detection programmes
In the face of revenue pressures, increasing operational costs, and manpower shortages, utilities can’t afford to ignore water loss. Nor can they afford to literally underestimate the problem.
As utilities review better methods to conserve water and control costs, leak detection has become a critical component of any modern utility management system.
By utilising mobile automatic meter reading (AMR) and fixed network advanced metering infrastructure (AMI) systems, utilities in the region can build successful leak detection programs.
Utilities with fixed-network AMI go from receiving a few meter readings per year to at least 24 readings per day. This data can be analysed to identify continuous usage, which is a leading indicator of which customers may have leaks inside their homes.
Traditional water meters are not only less accurate than smart meters, but they tend to lose accuracy as they age. The equipment must be replaced every 15-20 years on average, and many water utilities are now facing a natural replacement of their equipment.
With this opportunity, they should prioritise equipment that’s more accurate and allows customers to be better informed about and respond accordingly to their usage.
AMI for water, just as with electric meters, is a sophisticated two-way communication system that enables the utility and the customer to receive and react to real-time information, such as price signals and usage. But it goes beyond that.
They can also help prevent further deterioration. For example, a smart meter is more sensitive to low water flows, making it more accurate and comprehensive. In contrast, a traditional water meter measures total consumption of a building or home, meaning leaks are difficult to detect and customers can’t pinpoint inefficiencies.
By installing smart meters and sensors, both the utility and the customer are empowered with the information they need to improve efficiency and repair leaks earlier.
Some utilities that have fixed network AMI, such as Dubai Water and Electricity Authority (DEWA), have implemented proactive customer service efforts to help customers find leaks. Through such programmes, a customer is able to receive an email when their water use increases significantly over a period of several days. These notices allow customers to find and fix leaks before they receive a high bill.
Utilities are also making usage information available online, which allows customers to monitor their own water usage. Online usage data collected from the various smart meters installed allows customers to monitor their usage. Regular reports are also generated that allow the utility to identify customers who may have leaks inside their homes.
Most utilities estimate that 10 to 30% of water pumped into distribution systems is lost due to leaks before it even reaches customer meters. Utilities conduct audits to determine how much water pumped into the distribution system is actually metered.
AMI data can make these audits more accurate by helping utilities identify where loss may be occurring. For example, AMI data can identify meters that are not recording properly, either because they are broken or have been bypassed through theft. Unmetered water usage, whether authorised or not, is a key source of NRW loss.
In addition, a major NRW culprit is using the wrong-sized meter in an application, such as when a high-water-use business (e.g., a laundromat) moves into a commercial building originally developed for light industrial use. If the wrong meter is used, it may not record all the water that is used, which results in lost revenue.
Underground leaks in the distribution system are a primary cause of NRW loss but can be difficult to locate. Acoustic loggers integrated into a fixed-network system can cost-effectively identify small, underground leaks before they become big problems.
The loggers send data to the utility over the fixed network, where web-based application software automatically correlates the data and identifies and locates high-probability leaks. This approach simplifies acoustic leak detection, eliminating the need to send crews into the field and providing the means to manage the process from the utility.
Once the units are installed, operators can monitor the system and analyse results at the utility office. No manual or drive-by data collection is required. The system can be deployed stand-alone or added on to an existing STAR network AMI system, and operates with minimal operator involvement.
Several smart metering companies have deployed the technology across the GCC which use the system to find underground leaks that occur on hundreds of miles of galvanized service lines and cast-iron pipes.
When considering automation of meter reading, utilities should weigh the benefits of a fixed AMI network for a truly smart infrastructure. Improvements in customer service, conservation efforts, quantification of non-revenue losses, leak discovery, and operations improvements provide long-term, 21st century benefits over both drive-by and walk-by systems.
As water utilities are asked to quantify their costs and results, fixed-network communications networks that facilitate smart infrastructure solutions become a critical component of their technology toolbox.
For example, IZAR RC i Waterbox radio from Diehl Metering is devoted to conducting remote meter reading. IZAR RC i W module can be perfectly clipped onto all the meters of the Diehl Metering inductive modular range (Mixed or Ti), with grey ring. IZAR RC i W radio module, with great accuracy, transmits the meter reading, via an unidirectional link, every 8 seconds and offers a number of functions and alarms for leaks, reverse flow or when then meter is blocked.
In either Neptune technology’s AMR or AMI system, the keystone and starting point is the smart encoder – the E-Coder® solid state absolute encoder. An E-Coder-based system provides an advanced level of leak detection and detailed consumption data that accurately identifies water leaks on the customer side of the meter.
Providing advanced 8-digit, high-resolution data, the E-Coder provides resolution down to 1/10th of a gallon (1/100th cubic foot, 1 litre). This allows the utility to identify leaks that might otherwise be overlooked by lower-resolution encoder registers that cannot deliver granular enough data to the AMR/AMI system to enable postprocessing leak detection.
The E-Coder divides each 24-hour day into 96 15-minute intervals and monitors flow during each of those intervals. The E-Coder continually checks for consumption in each 15-minute interval, while its “smart” metrology distinguishes between intermittent and continuous leak conditions.
It also keeps track of the number of days the leak condition has existed. The E-Coder sets flags in the register to mark these leak conditions, updating the flags every 15 minutes. This level of advanced data, E-CoderPLUS data, is a valuable tool in water conservation and customer service. A small leak may seem insignificant. But if not caught early, it can add up to a significant volume of water.
Leak detection for most competitive systems is dependent on meter reading resolutions of 1 to 10 gallons from conventional 6-digit encoders. At best, these systems have to rely on algorithms programmed into the meter interface unit (RF MIU) or software analysis at the host to “infer” that a leak state existed – never really knowing whether there was a true leak.
A 6-digit encoder may not increment in an hourly interval with flows that are indicative of leaks, so neither the algorithm in the MIU or post-processing in the host can accurately determine whether a leak has in fact occurred.