Utility managers are continually challenged to run water systems in the most efficient manner. Reducing non-revenue water (NRW) is an important component for system efficiency. In many states, regulators are placing caps on NRW or requiring reductions in the amount of NRW. Accurate and well-planned flow measurement can be used to locate areas of water leakage and reduce NRW.
McCrometer is a leading global company specializing in flow instrumentation, innovating flow meters since 1955. Water Online spoke with Shriom Mourya, Product Manager at McCrometer to find out how specific types of flow metering can help find and reduce sources of NRW.
What is considered non-revenue water (NRW)?
Utilities produce and supply potable water to residents and businesses. They charge customers for water used, to obtain revenue for utility capital and operating expenses. The difference between the volume of water that utilities supply versus the volume of water they bill for is non-revenue water. The gap arises from loss of billable water between the treatment/production facilities and the end users. These losses can generally be attributed to leaks in the distribution network, metering inaccuracies, or theft.
Besides loss of revenue, are there other reasons to be concerned about NRW?
Loss of revenue is a primary concern. NRW also can increase operational costs of utilities, which are borne by the ratepayers. In addition, NRW represents a waste of critical water resources and reduced environmental sustainability.
How can flow monitoring help to find sources of NRW?
Flow meters can be placed throughout the distribution system between the treatment/production facilities and end users. This will help locate differences between volumetric flow rates between two points, which helps to pinpoint the location of water leaks or other inaccuracies.
What are recommended locations for flow meters for finding NRW throughout the distribution system?
It is good practice, and often required, to install a flow meter at the main supply pipe. Some water utilities then divide their network into defined District Metered Area (DMA) zones, like a subdivision or commercial area. Large meters are installed at the point where water enters the DMA. Water flowing to each DMA can be measured and compared with billing volumes. A large difference between water to the DMA and customer billing volume indicates potential leaks within the zone. Installing additional flow meters throughout DMAs with high losses to isolate flow pipes within the zone helps deduce leak points or inaccuracies.
What type of flow meter is recommended for such a water loss reduction program?
Electromagnetic flow meters are preferred over other technologies in water distribution networks. Depending on the pipe size, the overall cost of installing a full-bore magnetic meter can be expensive. McCrometer, Inc. offers a unique full profile insertion (FPI) electromagnetic flow meter that is suitable and economical for water loss reduction programs. FPI offers the same functionality and accuracies as full-bore meters, with much lower installation cost and overall ease of use.
How does a next generation full profile insertion (FPI) flow meter work?
FPI, like other full-bore or insertion electromagnetic flow meters, works on Faraday’s principle of electromagnetic induction. Water moving through a magnetic field produces a voltage directly proportional to the velocity of the water moving through the field. FPI’s multi-electrode design averages flow throughout the cross section of the pipe and delivers 0.5 percent accuracy.
What is the major benefit of using the FPI mag meter for finding NRW?
Many distribution networks are old/outdated and not designed for meter installation. FPI has no moving parts and can be easily installed through a hot tap. This allows the meter to be installed without interrupting service, de-watering lines, cutting pipes, welding flanges, or inconveniencing customers.
Can FPI meters communicate with SCADA systems or other data monitoring and logging systems?
Yes, FPI offers standard dual 4-20mA output that can communicate with SCADA systems. Also, McCrometer’s new Smart Output option allows FPI flow meters to communicate with existing advanced metering infrastructure/automated meter reading (AMI/AMR) systems.
How can the use of an FPI save costs for a leak detection or water loss reduction program?
Installing full-bore meters can get complicated very quickly. Many distribution networks are old and were not designed to accommodate flow meters. This is where FPI’s strength and value lies. Installing a 0.5 percent accuracy flow meter without having to interrupt service, de-water lines, cut pipes, weld flanges, or inconvenience customers provides direct cost savings. FPI’s versatility and ability to communicate with existing communication or data monitoring systems makes it the “go to” flow meter for leak detection and water loss reduction programs.
Image credit: "Penny Drop," Andrew Malone © 2007, used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by/2.0/
