Reducing Water Loss

In its 2009 Report Card for America's Infrastructure, the American Society of Civil Engineers stated that "each day, seven billion gallons of clean, treated drinking water disappears, mostly due to old, leaky pipes and mains." This is enough water to serve the population of a state the size of California. American Water is focused on implementation of technologies that encourage resource conservation and efficiency of this precious resource. We have found that many leaks appear to be related to water temperature changes and other factors that include soil movement, vibrations and water pressure changes. Early detection and repair of these leaks saves water and energy and reduces costs of repairs. Regular monitoring also enables us to notify customers who have leaks proactively before their water bills increase significantly. American Water is working towards keeping its water loss to a minimum and has a variety of programs in place to assist with this effort. Our research and development program has established a variety of successful programs to reduce “lost” water, and is also testing a number of innovative new technologies, some of which are outlined below.
Water Loss and Leak Control Technologies

Leakage Control Zones

Some American Water systems are subdivided into separate “zones of supply,” and utilize master meters to measure the water use in a specific area on a periodic basis. When a system experiences a higher than expected water flow in the middle of the night, it can be identified as a spot to investigate for onsite leak detection. This reduces the need to dispatch leak detection specialists into areas that are relatively leak-free. This is a common practice that is used in Europe but is just beginning to be utilized in the U.S. American Water estimates that 10% of its systems could be monitored using this method.

Pressure Control

Leakage Control Zones and other small water systems have some potential to have water pressure reduced in a way that still provides customers with needed supply but effectively reduces the amount of water flowing out of leaking pipes. Pressure management is a particular challenge for systems with significant changes in topography. Several projects undertaken by American Water, most notably in the Pittsburgh area systems, have not only reduced leakage but the damage that can be caused when leaks occur.

Continuous Acoustic Monitoring of Water Mains via Valves

American Water has placed FCS Permalog leak detecting sensors on water main valves that record sound vibrations overnight. Trained staff then drives by the sensors on a periodic basis to download the information into specially designed software that analyzes the pipe “noise” for the sound of leaks. Thousands of these devices have been installed across the American Water system across the country to replace the traditional method of leak surveying with field staff listening to pipes at night. This year another manufacturer, Metrotech, has provided an alternative version that is being tested in Pennsylvania American Water systems.

Continuous Acoustic Monitoring of Water Mains via Service Pipes: American Water has several systems utilizing Itron MLOG technology which equips water service lines with a leak detecting sensor that records sound vibrations over a period of four hours each night. The specially designed software analyzes these acoustical patterns and assigns them one of three leak categories: “no leak present,” “possible leak” or “probable leak.”

American Water is the first company to combine leak monitoring with Advanced Metering Infrastructure (AMI) communication. AMI allows us to look at pipe “noise” data on a daily basis without site visits, in order to analyze entire systems in a few minutes and at the same time, collect daily meter readings. This allows our leak technicians to focus on suspected leaks and pinpoint and repair those that would normally remain undiscovered, possibly leaking for months and causing significant damage. This technique is also available using a mobile (vehicle) collection system.

American Water is currently testing this approach for operations in Pennsylvania, New Jersey and California. American Water, in collaboration with the AWWA Research Foundation is also analyzing the potential benefits of this new technology to find leaks literally as they start.

Continuous Acoustic Correlation of Water Mains via Valves: American Water is entering a second test phase of a leak detection system that will confirm and pinpoint leaks before a work crew is dispatched in its Chicago-Metro district. Gutermann Zone Scans have been placed on water valves in the Valley View water system. The sensors are designed to detect water leak noise and will be connected to AMI (Advanced Metering Infrastructure) transmitters located in the valve box lids. Data will be transmitted daily allowing operators to perform correlation testing with any two working units, to identify the exact location of leaks between sensors. Last fall, the initial test of this system was successful in finding leaks using a portable version of the technology.

Large Transmission Main Testing

Though a rare event, the failure of major water transmission mains can have severe consequences in terms of water loss, interruption of service and damage. American Water is currently evaluating several complex methods to listen for leaks on large pipes. New Jersey American Water has piloted the PURE Smart Ball system that sends a sensor inside water pipes to find leaks. Pennsylvania American Water has tested the Echologics Leak Finder, which senses noise transmitted by running water while attached to the outside of a water pipe.

GIS Analysis

American Water has the ability to review historical leak information via GIS mapping, which more clearly identifies areas prone to repetitive leaks. We are currently utilizing this technology in Pennsylvania and New Jersey, where it has provided insight into the fact that the majority of leakage problems occur with smaller diameter pipes that were installed over fifty years ago.

Main Replacement Program

Using databases and GIS, American Water routinely collects and evaluates water system data. That data is used to identify main replacement projects that will effectively reduce the number of system leaks and the magnitude of lost water.