Editor-in-Chief Elisabeth Lisican showcases a handful of features to read in the April 2017 issue of Water & Wastes Digest.
Tips for reaping the greatest benefits from AMI
Utilities usually deploy advanced metering infrastructure (AMI) to improve billing accuracy and eliminate estimated reads. Applications that use the hourly data from fixed-network systems, however, can optimize performance, mitigate potential problems, and ultimately improve both economic and environmental factors that affect success.
Improving Customer Service
The hourly data provided by AMI give customer service representatives (CSRs) a leg up in efficiently and effectively answering customer questions regarding high bills. It provides CSRs with the information needed to pinpoint date and time of water use—analysis that is not possible when readings are collected monthly.
In addition, the information AMI provides allows utilities to track leaks and continuous usage on the customer side of the meter. Utilities then can identify what may be causing high water bills so that if a customer calls to ask about an unusually high bill, the utility is able to tap into the database and determine if there are periods of constant consumption that could indicate a leak. Based on this analysis, CSRs can advise customers to check areas likely to be the cause of the constant consumption.
Some utilities proactively reach out to customers to inform them of continuous consumption. This allows them to take action immediately, instead of learning about the leak from a large water bill. This is an especially useful tool for immediately identifying problems caused by an emergency, such as a burst pipe, which could cause costly damage if left unchecked.
AMI also can be useful in spotting small leaks that can add up. The Department of Environmental Protection in New York City, for example, reaches out to customers when continuous use by a customer is noted. By analyzing AMI data from its Aclara STAR network, the department has found thousands of small but expensive leaks, once logging 1,300 in three months. According to a report in the New York Daily News, one leaky toilet was costing a homeowner $26 a day for water, while a leaky garden hose cost $85 a day.
Enhancing Conservation Efforts
Most utilities conduct audits to determine how much of the water pumped into the distribution system actually is metered. Audits are expensive and time-consuming, often costing tens of thousands of dollars. The audits are based on methods developed by the American Water Works Assn. (AWWA) and International Water Assn. that identify non-revenue water loss from all sources, including consumption that is metered, unmetered and unauthorized.
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 authorized or not, is a key source of non-revenue water loss.
Many cities also provide usage data from AMI systems to customers online, allowing them to monitor their water use. Showing customers how they use water can be a springboard for conservation efforts. When customers know how much water they are using and when, they become more aware of their behaviors and can take proactive steps to curb usage.
Managing Meters in the Field
Availability of hourly AMI data allows for powerful trending analysis to spot meter anomalies. For example, utilities can analyze AMI data to identify meters that are not performing up to warranty standards. This is important because the meter shop can see whether a meter is working or not, but cannot easily determine if performance has degraded before the warranty period has expired.
Trending analysis also allows utilities to set up more accurate replacement schedules. Most meter shops schedule meter replacement at regular intervals—usually every 10 to 20 years. If analysis identifies one meter that is performing significantly worse than similar meters, the utility can target the poorly performing meter for replacement immediately instead of waiting for an arbitrary time period to pass.
In addition, a major non-revenue water culprit is using the wrong-sized meter in an application. These situations often occur when a high-water-use business such as a laundromat moves into a commercial building originally developed for light industrial use. If a meter is over- or under-specified for a particular setting, it will record water use improperly. A misread of a few percentages above or below the AWWA-recommended new meter standard of ±1% has a dramatic effect on meter accuracy and lost revenue. AWWA recommends that all used meters register at 95% or better.
A study for one Aclara water utility partner found significant meter sizing errors for its top 20 commercial customers. The resulting under-reads over the course of the year represented a staggering $400,000 in lost revenue. Harnessing data from AMI can, with data analysis, further leverage the value and investment of an AMI network.
Adding Smart Devices to the Network
Fixed AMI networks are not only designed for meter reading. The networks also can monitor many types of sensing devices, and utilities should consider using them to bring intelligence to their distribution networks.
For example, underground leaks in the distribution system are one of the primary causes of non-revenue water 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 associated with Aclara’s STAR ZoneScan system, for example, send data to the utility over the fixed network, and 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 head end.
Leak detection is not the only additional smart infrastructure solution that can take advantage of AMI networks. In the future, utilities will use their networks to monitor different types of sensors. Wastewater level and flow monitors, for instance, could help utilities manage sanitary sewer overflows.
Today, some sanitary sewer monitoring is done manually, with crews visually checking to make sure wastewater does not overflow into local waterways or exceed levels set by the U.S. Environmental Protection Agency. When they do, the utility may be subject to hefty fines. Wastewater sensors could automatically monitor discharge rates, allowing the utility to react quickly to situations in which discharge rates exceed limits.
Water utilities should consider their AMI networks as an effective tool to collect data from throughout the distribution network, bringing intelligence to areas of the system that may not be monitored.