Plugging the leaks in water pipes and building new ones to keep up with a growing population could cost the United States $1 trillion over the next 25 years, according to an industry study released Monday.
That study unearths a subject few Americans think about: buried drinking-water mains. As with aging highway infrastructure, however, the vast network of pipes built out during the boom years of the 20th century is now nearing the end of its life span.
"We've known for a long time that pipe networks are aging. We didn't appreciate the magnitude of the challenge," said Tom Curtis, deputy executive director of the American Water Works Association, which commissioned the report. "The size of the need was startling even to water professionals."
The report did not include wastewater lines, which could double the national price-tag.
Unlike other areas of infrastructure investment, Curtis said, utilities have invested in fixing drinking water lines -- but the need is about to ramp up as many lines reach the end of their lives. If water utilities try to delay repairs, he said, that would eventually translate into more money for repairs and new lines.
The water utilities the AWWA represents will spend differently depending on their region. In the Northeast, aging systems and stagnant population growth means cities and towns will spend more replacing old lines ($92 billion) versus building new ones ($16 billion) through 2035. In the fast-growing West, by contrast, new lines will cost $153 billion versus $82 billion to bring old systems up to snuff.
The report is more accurate and complete than previous efforts, like the drinking water report by the Environmental Protection Agency, AWWA argues, because it involves an exhaustive look, including pipe materials to soil types.
Curtis said that some older cast iron pipes -- the 100-year-old pipes often cited as a prime example of creaky water infrastructure -- are actually in good shape. "In 1900, almost all the pipes that were being laid down were cast iron pipe. Turns out that stuff lasts a very long time," he said -- up to 130 years.
Still, in many places the water bill is coming due. Payments will look very different from those for highways, which rely in large part on state and federal gas tax receipts that only loosely track how much people actually drive. Almost all money spent on underground water lines is paid for directly by users themselves through water bills. The cost is about $3.75 per 1,000 gallons of water, according to AWWA, but that could increase in years to come.
Aurel Arndt, general manager of the Lehigh County Authority, which oversees drinking and wastewater services near Allentown, Pa., said much of that system's expansion was in the 1960s or later, so pipes are still in good shape. But for older towns in the Northeast, he said, the future is more stark.
Replacing old water mains, said Arndt, who sits on an AWWA advisory council, "is going to challenge many communities, particularly those where they've been experiencing economic problems, and also in some places where the population has declined. You have a smaller customer base that has to pay a bigger bill, and that's never a welcome circumstance."