AWWA INF53950

AWWA INF53950 A Practical Approach to Distribution System Rehabilitation Planning
Conference Proceeding by American Water Works Association, 06/01/2001

Grablutz, Frank^McCammon, Sandra^Murphy, Laurence

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United Water New Rochelle (UWNR), whose parent company, United Water Resources,is a wholly owned subsidiary of Suez Lyonnaise des Eaux, supplies water toapproximately 133,000 people in southern Westchester County, New York. Theservice area includes residential and commercial districts in ten municipalitiesjust north of New York City. UWNR's distribution system is comprised ofapproximately 440 miles of pipe. The median age of the distribution system pipeis 75 years; 66 miles of the pipe were installed over 100 years ago. Bycomparison, the median ages of distribution system pipes in Philadelphia andBoston are approximately 70 years and 48 years, respectively. UWNR recognized theneed for a proactive pipe renewal program in order to ensure good quality serviceto its customers into the future. The term renewal encompasses both replacementof pipe and rehabilitation of pipe to prolong its life. As an investor-ownedutility, UWNR needed to provide the state Public Service Commission (PSC) with adetailed and well-documented renewal plan in order to receive the rate adjustmentneeded to fund the program. Rates are expected to rise due to the aggressivenature of the renewal plan. UWNR expects to spend $6 million annually in currentdollars just on pipe renewal. That is significantly more than the historicalaverage annual total capital expenditures of $3 million in current dollars. Thus,Roy F. Weston, Inc. was retained by UWNR to develop a long-term distributionsystem pipe renewal plan and prioritization schedule. This paper describes thedevelopment of the long-term water main renewal plan for UWNR. First, therationale behind the prioritization process is presented. Next, data availabilityand the data collection process are described. Finally, the results of theproject are presented along with general suggestions to assist other utilitiesplanning their own long-term renewal programs. Includes reference, tables, figures.