HARRISBURG, Pa. (AP) - Pennsylvania and the Marcellus Shale natural gas reservoir are emerging as a key focus of natural gas pipeline operators, as the increasing gas flow spurs projects to bring it to customers in the northeastern United States and possibly Canada.
More than half of the interstate natural-gas pipeline projects proposed to federal energy regulators since the beginning of 2010 involve Pennsylvania - at a cost estimated at more than $2 billion.
That means hundreds of new miles of pipeline as part of a larger, traditional cross-country network that already extends through Pennsylvania and its neighboring states, as well as dozens of new or upgraded compression stations to force more gas through the buried pipes.
The projects are already employing thousands of contract workers and bringing work to steel mills, welders, gravel quarries and landscapers. At the same time, they are generating concerns about air and water pollution and eminent domain issues.
Combined, more than a dozen projects proposed or already under construction would have the capacity to move an additional 4 billion cubic feet of natural gas a day - one-third of what analysts for Colorado-based Bentek Energy say is the average daily demand in the northeastern United States.
"A lot of those projects are really designed to move the new volumes out of the Marcellus to your more traditional, historic pipelines that have served the Northeast markets for the last 30 or 40 years," said Bentek's manager of energy analysis, Anthony Scott.
For now, Bentek said about 3 billion cubic feet (bcf) per day of gas is flowing from the Marcellus Shale, the nation's largest-known natural gas reservoir. Production is rising quickly as crews busily drill more wells, and the flow should easily reach 7 bcf or 8 bcf per day in the next five years, Scott said.
But the exploration companies need to find takers for the gas, and Bentek analysts say more pipeline capacity is needed if the Marcellus Shale gas is going to ease price spikes at important New York City and Boston-area hubs during the coldest winter stretches.
Where the gas is already flowing into interstate pipelines, largely in southwestern and northeastern Pennsylvania, it is displacing pricier gas from more distant sources including Canada, the Gulf Coast, Rocky Mountains or terminals that accept liquid natural gas shipments from overseas, Bentek analysts said.
Similar pipeline construction followed earlier growth in shale gas production in Texas, Louisiana and Arkansas, said Jeffrey Wright, director of the Office of Energy Projects at the Federal Energy Regulatory Commission.
"You test it, you produce it and you develop it, and when things look promising, you have to have a way to get the gas to market, and that's when the pipeline proposals start coming in," Wright said.
The expansions come amid scrutiny after several high-profile pipeline accidents around the country and the need for Congress to re-authorize the last significant pipeline safety rules, adopted in 2006.
Armed with billions of dollars and a new technique for tapping gas from thick rock - hydraulic fracturing, or fracking, combined with horizontal drilling deep underground - major drilling companies began descending on Pennsylvania in earnest in 2008 to exploit the Marcellus Shale.
The formation lies primarily beneath Pennsylvania, New York, West Virginia and Ohio. Pennsylvania is the center of activity, with more than 3,000 wells drilled in the past three years and thousands more planned in coming years.
Cathy Landry, spokeswoman for the Interstate Natural Gas Association of America, said pipeline construction historically has been driven by demand from gas utilities or power plant owners. With the growth in gas production, partly from the Marcellus Shale and other shale regions now being explored, it's the exploration companies that are pressing for pipelines.