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Across the country, utilities have a big problem: Aging natural gas pipelines that leak. The issue gained new attention after an explosion in New York last month. It leveled two buildings and killed eight people. Replacing old steel and cast iron pipes with plastic ones can take decades and billions of dollars. Still, some utilities are making that a priority.
NPR's Jeff Brady reports from Philadelphia, where after a long, cold winter, construction crews are back at work.
JEFF BRADY, BYLINE: We're on a residential street in Philadelphia. A utility worker is crouched in a freshly dug hole in somebody's yard. He's cutting through an old, two-inch steel pipe. When he's done, gas will flow to this house through a new, bright yellow plastic pipe. Look out at the street and there's a line of fresh blacktop next to the curb. That's where crews also replaced a much larger, six-inch cast iron pipe that carries gas to the entire block.
Joseph Hawkinson is the superintendent of construction for Philadelphia Gas Works. When deciding which pipelines to replace first, he says the utility looks at things like the number of gas leaks and repairs.
JOSEPH HAWKINSON: Through that analysis, we identify each year 25 miles of cast iron pipe to be replaced.
BRADY: At 25 miles a year, how long will it take you to finish?
HAWKINSON: Right now, our program is at 88 years.
BRADY: That's more than 2,000 miles of pipe. And the price tag is hefty - right now, about $77 million a year, says Hawkinson. Cost is important because that gets reflected in customers' utility bills. Philadelphia is just one city facing this issue. Research firm SNL Energy looked at federal data and compiled a list of large utilities with the highest ratio of leaks per mile of pipeline. Michael Carter is a director with the company.
MICHAEL CARTER: And, you know, it comes out as a very interesting list - concentrations in New York and Pennsylvania. But also, there's other companies up there that have a number of leaks in Texas or Virginia.
BRADY: New York's Con Edison tops the list with about one leak per mile of line; number two is Philadelphia Gas Works. Considering they are two of the oldest distribution systems in the country, that's not too surprising. The longer a pipeline is in the ground, the more likely it'll corrode or crack when it's cold. Fixing the leaks is important. On top of the safety concern, gas released into the air is bad for the environment.
When incidents like the explosion in New York last month happen, it can be tempting to conclude that all old pipes need to be replaced quickly. But it's just not that simple, says Richard Kuprewicz, president of Accufacts Incorporated, which investigates pipeline accidents.
RICHARD KUPREWICZ: I keep telling people over the decades, safety isn't free, all right. However, the excuse for safety is not an excuse to write a blank check.
BRADY: The key is striking a good balance between safety and cost, say Kuprewicz. These days, utilities are concluding more money needs to be spent replacing old pipelines. In Philadelphia, customers' bills now include an extra fee. That's helping the utility boost the number of miles of cast iron pipes it replaces each year by nearly 40 percent.
Jeff Brady, NPR News, Philadelphia.