A massive natural gas pipeline explosion in West Virginia this week has heightened awareness of the safety issues related to Pennsylvania's almost 60,000 miles of natural gas pipelines.
Pipeline transportation of natural gas has a good track record and a federal study shows it is safer than rail or truck shipping, but the pipeline explosion Tuesday near Sissonville, along Interstate 77, 15 miles north of Charleston, highlights its often overlooked and sometimes fiery risks.
There are more than 2.5 million miles of pipelines running through the U.S., approximately 60,000 of which are in Pennsylvania. Concerns have heightened as new pipelines are laid to service burgeoning shale gas development in Pennsylvania and other states, and older pipelines corrode and crack, increasing the possibility of leaks and accidental explosions. A recent federal report found more than half of the pipelines in the U.S. are 50 years old or older.
And while the West Virginia pipeline accident didn't cause any injuries or fatalities, the U.S. Transportation Department's Pipeline and Hazardous Materials Safety Administration data show pipeline accidents have caused the deaths of 68 people nationwide in the last five years, 21 of those pipeline workers.
In Pennsylvania last year, five people were killed by an explosion in Allentown caused by a corroded pipeline and one person died in a pipeline explosion in Philadelphia.
The PUC regulates 46,000 miles of distribution lines -- the utility lines that transport natural gas to communities, 1,000 miles of intra-state transmission lines that carry gas longer distances from gas producing regions to distribution facilities, and about 870 miles of the almost 2,200 "gathering lines, which transport natural gas from well sites to compressor stations.
"We can go years with zero incidents, but when they do happen they gather headlines and are typically tragic. We have our inspectors out every day to make sure we can avoid those kinds of things happening," said Jennifer Kocher, a spokeswoman with the Pennsylvania Public Utility Commission, which has regulatory authority over the vast majority of pipelines in the state, but not interstate transmission lines like the one that ruptured in West Virginia.
It does not have "safety jurisdiction" over the 1,300 miles of gathering lines, known as "Class 1" lines, linking shale gas wells to compressor stations or other processing facilities, but under provisions of a 2011 state law the pipeline companies must register those lines with the PUC. The gathering lines are classified Class 1 because they are located in areas where there are less than 10 homes within a one mile radius of the line. Class 2, 3 and 4 pipelines are located in more populated areas.
Regulation of the interstate pipelines like the one that exploded in West Virginia, falls to the federal Pipeline and Hazardous Materials Safety Administration and there are approximately 9,000 miles of those in Pennsylvania. According to PHMSA statistics, there were 21 "significant" incidents on those transmission lines from 2002 through 2011, but no fatalities and only two injuries.
"Safely developing and transporting natural gas to end users is of paramount importance to the natural gas industry. With nearly 10,000 miles of inter- and intra-state natural gas transmission lines in Pennsylvania, and very few incidents over the past 10 years, the industry's safety record here in the Commonwealth is constantly improving," said Steve Forde, vice president of the Marcellus Shale Coalition, a gas industry advocacy organization.
Mr. Forde said the industry has improved its maintenance procedures and the coalition supports the PUC's "call before you dig" one-call system to locate pipelines before any earth-moving work is done. "Line hit" by excavators is the No. 1 cause of gas pipeline accidents in the state.
The aging pipeline infrastructure is also a prime concern, said Ms. Kocher, who said a study shows the state's 10 largest gas utilities will need to spend $12 billion over the next 20 years to replace aging cast iron and bare steel pipes that are in danger of corroding and have become brittle because of the state's freeze-thaw cycle.
She said Act 13, the state's oil and gas law passed in February, established a "distribution system improvement charge" that will allow gas utilities to expedite the needed gas pipeline improvements.
Pennsylvania has historically been a net consumer of natural gas, with most of the larger interstate transmission lines bringing gas into the state from the Gulf Coast states and the Midwest. It has very little gathering pipeline infrastructure but that is changing, according to Dave Messersmith, a member of the Penn State Extension Service Marcellus Shale education team.
"There has been a rapid increase in the development of gathering pipelines to move the gas to market, and as more wells are drilled, more pipelines will be needed," Mr. Messersmith said. "One of the causes of the drilling slowdown in the state, along with low gas prices, is the lack of pipeline infrastructure."
Most of that pipeline development is occurring in the gathering lines running from Marcellus Shale wells, which are not regulated by the PUC or the federal PHMSA. But, as a state report on pipeline placement issued Tuesday by Patrick Henderson, Gov. Tom Corbett's energy executive, notes the federal agency is considering extending its jurisdiction to those unregulated lines.
"There will be a discussion on regulating Class 1 gathering lines in the coming year. I expect the Legislature to do that," Mr. Henderson said.
He said that regulating Class 1 gathering lines is "at the bottom of the state's priority list" because few people would be affected, but if the federal agency decides to regulate them, Act 13 would require them to be added to the PUC's oversight responsibility.