LOGAN, UT, Apr. 19, 2012 -- The Utah State University (USU) Buried Structures Laboratory has published a comprehensive study on water main break rates for the United States and Canada. In it, water main break rates are calculated for all pipe materials used in the transport of water to create a measurement to judge pipe performance and durability. The study is expected to help prudent decision-making as it relates to repairing and replacing underground pipes.
The study "Water Main Break Rates In the USA and Canada: A Comprehensive Study," conducted by Dr. Steven Folkman, co-author of Buried Pipe Design, looked at 188 utilities representing approximately 10% of the nation's installed water main pipe network.
The study found that PVC pipe has the lowest overall failure rate when compared to cast iron, ductile iron, concrete, steel and asbestos cement pipes.
The study also found that corrosion is a major cause of water main breaks. About 75% of all utilities have corrosive soil conditions and high proportion of old cast iron and ductile iron pipes, making corrosion the second highest cause of water main pipe failure in the United States. When comparing between older cast iron and newer ductile iron, thinner-walled ductile iron is experiencing failures more rapidly.
Other findings include a new national metric of 264 people per 1 mile of pipe connections regardless of utility size. The average age of failing water mains is 47 years old and 22% of all water mains are over 50 years old.
The study also found that 8% of all installed water mains are beyond their useful life. The use of trenchless technologies will continue to increase with directional drilling as the most widely accepted technology with a higher satisfaction rating. Seventy-four percent of utilities are considering it in the near future.
This study contributes to the continuing efforts of the EPA's Aging Water Infrastructure (AWI) research and the American Water Works Association (AWWA).
The Water Main Break Rates In the USA and Canada: A Comprehensive Study can be found at:
http://www.neng.usu.edu/mae/faculty/stevef/UtahStateWaterBreakRatesHR.pdf (High resolution)
Dr. Steven Folkman is a registered Professional Engineer, a member of American Society for Testing and Materials (ASTM) F17 Plastic Piping Systems, a member of AWWA and a member of the Transportation Research Board Committee on Culverts and Hydraulic Structures, and has oversight of the prestigious Utah State University's Buried Structures Laboratory (USU - BSL). USU - BSL has been involved in analysis and testing of all kinds of pipe and associated structures for over 50 years and is recognized as one of two laboratories in the U.S for performing large scale tests on buried pipes. Dr. Folkman's expertise includes structural dynamics, linear and nonlinear finite element analysis utilizing soil/structure interaction, and testing.