The gas pipe that leaked and is believed to have caused a massive gas explosion in Allentown nearly one year ago was first installed in 1928.
Eighty-three years old at the time, the pipe was slightly below the average age of the cast-iron pipelines running through the city.
Out of about 72 miles of cast-iron pipe in Allentown, the average pipeline age falls between 90 and 120 years, according to Mayor Ed Pawlowski.
One year after the Feb. 9, 2011, blast that claimed five lives and destroyed eight houses, Pawlowski said he thinks UGI is still not doing enough to speed up replacing the aging pipes.
The public utility company told a special U.S. Senate committee last year it would take 40 years to replace all of the city’s cast-iron pipes.
UGI officials say they have stepped up the pace at which they are replacing cast-iron pipe with high-density plastic in Allentown and the rest of the Lehigh Valley.
The company replaced seven miles of city gas main in 2011, UGI spokesman Joe Swope said. That’s more than the six miles it planned to replace, which itself is more than twice what the company had replaced the year before.
In 2012, UGI plans to replace seven and a half miles of pipeline, Swope said. That would leave about 64.5 miles of cast-iron pipe in the city.
But replacing pipeline costs about $650,000 per mile, and UGI officials have previously said they cannot replace gas lines at this pace every year.
Even if they stuck to six miles per year, Pawlowski said, it would take more than a decade to replace it all, which the mayor said is too long.
If undisturbed, cast-iron pipe can operate for years without problems. But as they age, they become less resilient and more susceptible to leaks, cracks and pressure from street traffic.
The new pipe installed by UGI is made of a sturdier high-density plastic, Swope said, which is often sleeved through the existing cast-iron pipe to create an additional layer of protection.
There are 217 miles of cast-iron pipe in the Lehigh Valley. That does not include 13 miles worth that were replaced in 2011, Swope said.
Since most of the Valley’s cast-iron pipeline falls outside Allentown, this is a regional concern, not a city issue, Pawlowski said.
As of 2010, UGI’s three utilities in Pennsylvania have 11,627.49 miles of pipeline statewide, according to the Pennsylvania Public Utility Commission.
Of that, 1,827.197 miles, or 15.71 percent, are either cast iron or bare steel, which PUC spokeswoman Jennifer Kocher described as “risky pipeline.”
Swope said that since 2000, UGI has replaced more than 290 miles of cast-iron pipe systemwide, and the company spent $43 million on natural gas main and service replacements last year alone.
It will probably cost UGI about $4.9 million to replace the seven and a half miles of cast-iron pipeline it plans to replace this year in Allentown, Swope said.
Among the challenges in replacing older pipeline is finding construction crews qualified for the work and working with municipalities to determine which mains should be replaced in which order, he said.
There are 60,418 miles of pipeline throughout the state, according to the Pipeline Safety Trust, a Washington, D.C.-based watchdog group
Of that, 47,051 are for gas distribution and service, 10,834 are gas transmission and 2,532 are hazardous liquid, according to the organization.
Nationally, 31 percent of gas distribution lines were installed prior to new regulations in the 1970s, according to the U.S. Department of Transportation.