By Kathryn Kretschmer-Weyland
November 11, 2008

As water resources become more expensive and environmental regulations tighter it is imperative that cities implement measures to eliminate water leaks and losses. One way to identify non-revenue water loss is through better data collection and analyses.

Water departments that collect monthly meter reads are not collecting enough information to perform proper analyses. Cities must gather water usage data daily, if not hourly, to understand how the water system is working.

The SmartRead program in Boston, for example, employs the wireless STAR® Network system advanced metering infrastructure from Aclara to collect data four times a day from approximately 90,000 meters. In Boston, leaks are caught earlier because discrepancies in water usage are readily identified by analysis of meter data.

The meter readings are evaluated to determine if water usage fluctuates substantially over time, or if it is elevated when city buildings are closed. Information collected as part of the SmartRead program helped the Boston public school system identify leaks at a number of buildings that were costing it over $3,000 a month, for instance.

Plugging water-main leaks before they become expensive problems is another way to reduce non-revenue water loss and positively impact water resource-management efforts. Remote, correlated acoustic-leak detection can identify these small leaks before they become major problems. Aclara’s STAR®-ZoneScan (STAR-ZS) system, which combines the fixed STAR Network system with the Zonescan 800® leak-detection technology from Gutermann International, Zurich, Switzerland, promises to make accurate, remotely correlated acoustic leak detection a reality.

The STAR-ZS system literally “listens” to the sounds of water flowing through the main. Anomalies in the sound of water are picked up by a sensor placed on a valve or hydrant on the main, transmitted to a device located in the pit lid, and sent by way of the wireless fixed network to the utility. STAR-ZS units can be set up permanently, or can be moved around the water system.

Once the acoustic data is received by the utility, it is analyzed and correlated to identify leak locations. STAR-ZS devices can pinpoint the location of leaks to within a few feet. The accuracy of the system reduces the time it takes to find a leak and the amount of field work that must be done to repair it.

What differentiates the Aclara system from other approaches to leak detection is its ability to analyze the data provided by the acoustic sensors. Other solutions simply assign leak values to specific points in the water distribution system to indicate the likelihood of a leak, and a crew must be sent to the field to conducts tests to find the leak. The Aclara STAR-ZS system actually correlates the leak values to pinpoint leak locations remotely.

For additional information about Alcara, contact Kathryn Kretschmer-Weyland at 301-460-5251 or send email to kweyland@usmayors.org. You can also visit Alcara’s website at: www.aclaratech.com