Aging natural gaslines pose hidden threat across U.S.
Early one recent morning in Pittsburgh's Squirrel Hill neighborhood, a crew of utility workers in hard hats and neon yellow safety vests worked to defuse a time bomb.
About six feet below street level, in a trench dug by Peoples Natural Gas Co. workers, lay two sections of foot-wide, yellow plastic pipe they would join. Nearby, a woman and small boy pressed smiling faces to the screen window of a house, the boy enthralled by the workers' activity.
This pipe, less than 10 feet from the house, replaced a pitted cast iron tube laid by a generation of utility workers 90 years or more ago. The old pipe is like nearly 100,000 miles of natural gas distribution lines serving homes and businesses across the country. No one knows their true age — or when wear might lead to rupture.
“We have a ticking time bomb under most of our cities, especially in the Northeast where we have older cities,” warns Allentown Mayor Ed Pawlowski.
He knows the importance of replacing pipe like the one in Squirrel Hill. In 2011, a gas explosion killed five people and destroyed most of a block of his Lehigh County city. The only explosion deadlier in the past decade happened March 12 in East Harlem, N.Y., when eight people died. That explosion destroyed two apartment buildings and injured 48 people.
Accidents involving gas distribution lines have killed more than 120 people, injured more than 500 others and caused more than $775 million in damage since 2004, according to a Tribune-Review analysis of U.S. Pipeline and Hazardous Materials Safety Administration records. The damage figure doesn't include millions of dollars awarded from civil lawsuits to survivors, and other costs.
This distribution network to homes and businesses, not to be confused with much larger interstate transmission lines, includes nearly 1.3 million miles of pipe. And the older those pipes get, the more they leak, officials say.
Two Western Pennsylvania utilities, Peoples Natural Gas and Columbia Gas of Pennsylvania, plan to spend more than $1 billion to replace pipe during the next few years. Other utilities around the state and the nation will spend billions more to remove high-risk pipe.
Pennsylvania averaged one natural gas leak for every three miles of distribution pipe last year, the Trib found, making the Keystone State's one of the leakiest systems.
One in five miles of Pennsylvania pipeline — nearly twice the national average — is older than 1960, federal data show. During the past 10 years, gas explosions killed 10 people and injured 21 in the state.
“The number one predictor of leaks is old piping,” said Rob Jackson, a professor of environmental science at Stanford University. Jackson uses methane sensors to map gas leaks in major cities with aging infrastructure.
Records of that infrastructure can be unreliable. Some date to the Civil War and companies that long ago ceased to exist.
“There's always a line here or there that doesn't show up on any map,” said Guy Costa, Pittsburgh's chief operations officer.
Natural gas contains 20 times the energy of TNT, according to the Lawrence Berkeley National Laboratory in Berkeley, Calif. It's invisible, and odorless without the mercaptan that gas companies add to give it a rotten-egg smell.
When a line breaks, the gas begins to surface. If pavement or packed earth block its rise, the gas can move sideways through softer soil, seeking a hole.
Usually, it finds open air. But on Feb. 9, 2011, gas in the 83-year-old pipe under Allentown found homes at 542 and 544 North 13th St.
Methane swirled with oxygen and, at 10:48 p.m., the gases ignited. The explosion obliterated the two homes, killing all five people inside them and setting fire to much of the block.
It took several hours to cut off fuel to the raging fire, Pawlowski said.
Long time coming
Pipes made of cast iron and bare, unprotected steel make up less than 6 percent of the natural gas distribution network in the United States. Yet those pipes account for 95 percent of leaks, the state Public Utility Commission said.
Across the country, nearly 75,000 miles of such pipe remains in use, federal records show — mostly under Texas, New York, Pennsylvania, Michigan and Ohio.
The highest concentration of risky pipe in Pennsylvania is under its most populous city. Cast iron makes up half of Philadelphia's 3,000 miles of pipeline, the Trib found. Philadelphia Gas Works reported the highest rate of leaks in the state in 2013 with 89 per hundred miles of mains — eight times the national average.
Utilities stopped using cast iron and unprotected steel by the end of the 1960s, and federal regulators urged them to replace it starting in the 1970s.
Forty years later, more than 10,000 miles of such pipe remains under Pennsylvania, federal data show. The PUC estimates it would cost $11 billion — about what the state spends on education this year — to replace.
“Should we replace it? Yes. But how do we pay for all of that?” Gov. Tom Corbett said during a recent interview with the Trib. “Replacing (pipe) isn't as nice as building a park or building a bridge, is it? Oftentimes, isn't it the emergency that causes movement, rather than planning?”
For Pennsylvania lawmakers, it took two emergencies.
Weeks before the 2011 Allentown explosion, a 19-year-old Philadelphia gas worker died in an explosion while investigating a leak. A year later, Corbett signed a law allowing utilities to add up to 5 percent to customers' bills to recoup infrastructure costs to replace gas lines.
The disasters sped up gas companies' plans as well.
“Things like that have driven us at a greater rate to change out our infrastructure,” said Ken Johnston, Peoples' vice president of operations.
Peoples plans to spend $500 million over five years on pipelines, which it can't recoup from rates for at least five years because it is operating under a rate freeze, spokesman Barry Kukovich said.
Peoples expects to replace the last of its cast iron pipe this year, and its approximately 4,000 miles of unprotected and bare steel pipe over 20 years, Johnston said.
UGI Utlities, in a settlement with the PUC over the Allentown explosion, promised to replace its cast iron mains by 2027 and bare steel by 2043.
Before the 2012 law, some companies' replacement schedules ran longer than 100 years, said Gladys Brown, a PUC commissioner.
“With some of these proposals, they're getting down to 30 years to replace it,” Brown said.
The law increased the maximum penalty the PUC can impose on a company from $500,000, the amount the commission fined UGI, to $2 million.
Pawlowski worries that dangerous pipelines will remain in use for decades. He and Mayor Jim Ruane of San Bruno, Calif. — where a larger gas transmission line explosion killed eight people in 2010 — formed the Mayors' Council on Pipeline Safety. They try to get other mayors to pay attention to something neither of them thought much about before their cities' tragedies.
“It's going to happen again,” Pawlowski said. “It's just a matter of time.”
Mike Wereschagin is a staff writer for Trib Total Media. He can be reached at 412-320-7900 or email@example.com.