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Lower Prices, Consumption, Near-Term Construction Lessens 2010 Spending Levels
For our annual pipe report, managers at LDCs were again queried to comment on several subjects, including the cost of finding and repairing leaky mains. The cost figures and comments from industry participants on these and other topics follow.
As in past years, those surveyed unmistakably report the utility industry is replacing older, leaking, inefficient and structurally deficient mains and services. As to ongoing programs to replace existing cast iron or unprotected steel mains with plastic or protected steel, 68 percent of those surveyed report programs in progress while 17 percent indicated they had no cast iron or bare steel in existing systems. Of the 13 percent reporting bare steel in existing systems, leak history was consistently cited as a primary area of focus. Just 2 percent of those surveyed indicated they had not yet started a long-term program to replace bare steel and cast iron in existing systems.
Most residential pipe installed in the past 30 years has been plastic, chosen for its flexibility and resistance to corrosion. Today alone plastic reportedly accounts for more than 39 million services and 3 billion feet of the pipes in service and over 97 percent of all new gas distribution piping installed each year.
After decades of successfully using polyethylene pipe in sizes up to 12-inch diameter, utilities are recognizing the potential for larger diameter applications in gas distribution lines. Cities such as Chicago and Kansas City have used large-diameter gas pipe mains for many years to renew the cast iron pipes that reached the end of their service lives. The availability and ease of installation of pipes offer safe, economical solutions for large-diameter gas pipe mains.
Survey recipients also indicate that 2- and 4-inch diameter PE pipe is widely used in the gas utility industry and accounts for 95-98 percent of all new main installations in developed areas. As to cost, the following figures reflect the average cost per foot reported to install plastic and steel mains. Costs for plastic main installations ranged from $16.70 to $10.20 for 2-inch diameter; $13.60 to $20 for 4-inch; and $12 to $33.50 for 6-inch.
Those reporting protected steel main installation costs listed the following: 2-inch, 17.35 to $20 foot; 4-inch, $28.20 to $30; 6-inch $33.05 to $45; and $60 to $74.70 for 6-inch.