National Survey on the Trends in Small-Diameter Water Pipeline Failures

A national survey was conducted during the years 2008-09 by the Center for Innovative Grouting Materials and Technology (CIGMAT) at the University of Houston in collaboration with the City of Houston to document the conditions of small-diameter (< 500 mm diameter) water pipelines in the United States and Canada. Several major cities and few smaller cities participated in the survey, representing a population of 11 million and a water pipeline length of more than 28,000 mi with pipe diameters less than 500 mm. The survey results were analyzed with number of local parameters to establish the general trends observed in the water pipeline failures. The results were also compared with the one conducted by the U.S. Mayor in 2007. The survey conducted by U.S. Mayor included more than 290 cities, representing a population of more than 30 million with water pipeline length of more than 100,000 mi. By comparing the two surveys, the CIGMAT survey represented somewhat larger water systems with several cities having total water pipeline length greater than 1,000 mi. Based on both surveys, the water pipeline breaks per day varied from 0.002 to 12. From the CIGMAT survey, it was possible to investigate the relationship between water pipeline breaks or breaks per mile with numbers of independent variables and the total pipe length in a city was an important parameter. In this study, few relationships were developed for water pipeline breaks using the CIGMAT survey data and the predictions were compared with the USCM survey data.