By Dan Pinney
Most utilities understand they have a nonrevenue water problem, but few know how to deal with it correctly. Start by learning more about how the issue affects your utility and what options are available.
Non-revenue water (NRW) can quickly add up. In fact, North American water providers are getting paid for only roughly 70 to 80 percent of the water they distribute. That leaves utilities with a big gap to fill between the volume of water they supply and the amount of water they bill to customers each month.
This challenge is nothing new in the industry, but utilities no longer have to miss out on meeting revenue potential or incur unnecessary operational expenses due to NRW. Solutions are available today to help identify the sources of NRW and reduce them. And, when implemented strategically, these solutions can be combined to create a system that will pay for itself and produce cost savings into the future.
Answers For Apparent Water Loss
Apparent loss happens when water is produced but not measured. Utilities can enhance metering performance and improve administrative capabilities to minimize apparent water loss. They can quickly generate significant cost savings by focusing on three key areas:
- Meter accuracy— Mechanical meter components experience wear, so there may be performance issues over time that cause the meter to not record all of the consumption. Replacing or recalibrating older meters could help restore accuracy and often increases the revenue capture by 10 to 20 percent. Installing new meters could help jumpstart the revenue curve and potentially save millions of dollars.
- Billing — Billing records can be lost when completed manually or lead to issues with units of measurement if systems were not installed correctly. For example, a utility might record data in cubic feet but bill in gallons — meaning customers aren’t paying as much as they should for their water. Utilities can streamline the billing process to reduce errors using an automated system coupled with an advanced metering infrastructure (AMI) solution.
- Unauthorized use— Alarms can help utilities detect meter tampering and access from unauthorized personnel. Smart alarms with tamper alerts help utilities detect attempted theft and prevent additional lost revenue.
Some utilities might take a progressive approach in deploying solutions for apparent water loss. For example, improving meter accuracy often serves as a good first step, as it allows utilities to invest the cost savings in updating their operations. Each step is financially supported by the previous one.
"Utilities can build a platform to address real loss by enhancing water distribution management and monitoring systems to protect infrastructure against leaks and spills."
Reducing Non-Billable Usage
Most utilities have some level of non-billable usage within the distribution system. Typical examples include flushing, hydrant testing, other fire department use, and consumption by the utility or municipality itself. Consumption of this nature is needed and has valuable safety, public health, and social impacts. Often, the consumption of water for these purposes can be reduced by deploying a smart utility network to monitor these activities. Solutions include:
- Metering — Deploying meters to monitor hydrant testing and municipal usage can provide accountability to drive conservation efforts.
- Trending — Monitor flushing in conjunction with water quality parameters to reduce the amount and optimize both losses and costs while maintaining appropriate water quality levels.
Resolving Real Water Loss
Real loss occurs when a leak or spill happens, and the water never gets to the customer. Utilities can build a platform to address real loss by enhancing water distribution management and monitoring systems to protect infrastructure against leaks and spills. Key solutions include:
- Mass Balance — A mass balance platform gives utilities a view of water consumption compared to water production and/or purchase. The use of district meters may also segment the network to provide additional focus on specific regions. If something comes up, service technicians will know which region to focus on to address the issue quickly and efficiently. This system also allows utilities to understand which zones might be prone to water leakage, further increasing accuracy and efficiency by allowing better prioritization of preventive maintenance.
- Pressure Monitoring— The ability to monitor pressure in the distribution system provides a variety of benefits. Monitoring pressure at 3 to 5 percent of the service connections and at elevated points within the distribution system provides indications of pressure drops due to real losses. It also identifies areas for additional focus on real loss pinpointing, quantification, and potential repair or replacement strategies. Moreover, pressure provides insights into system behavior and can enable a proactive approach to addressing system issues such as low or high pressure and pipe bursts or leakage.
- Level Monitoring — By using a smart utility network, personnel can monitor storage tank levels and alarm thresholds to avoid spills and overflows at these locations. • Acoustic Solutions — Leveraging sensors with the ability to listen for acoustic leakage signatures, the utility can monitor distribution lines and precisely locate leaks. Sensors compare background noise to the current levels and then report pipeline conditions to the utility through a communication network. The data can then be analyzed to determine whether and where a leak condition exists, and service crews can make any necessary repairs before the issue gets worse.
- High Resolution Monitoring — Once areas of concern have been identified by using district mass balance or pressure monitoring, a utility can choose to deploy high resolution sensors to provide definitive identification of the issue. High resolution sensors include inline hydrophones, transient monitors, acoustical correlators, and in situ devices that examine the distribution pipes. These sensors can provide additional data on time signatures of surges, pipe conditions, leak locations, and more. While the previous solutions will allow a utility to address a significant amount of NRW, advanced leak detection provides the capability to gather much more data and fine-tune leak detection to specific percentage points.
To determine the best approach for reducing NRW, utilities should assess apparent and real water loss solutions based on their own needs and budget. Some utilities may want to deploy individual solutions for specific situations, while others may aim to implement a step-by-step system to advance their overall water loss prevention efforts. With the right system, utilities will be able to maximize water system health and accuracy with immediate savings that will continue to pay dividends.
About The Author
Dan Pinney is the global director of water marketing for Sensus, a Xylem brand. Pinney has 28 years of experience in the global water industry with leadership roles in operations and development. He graduated from the University of Florida with a major in electrical engineering.