"It's the producers who want to get their gas to market," she said.
One of the largest projects, a $700 million expansion of Tennessee Gas Pipeline Co.'s 300 pipeline, is already under construction, employing 2,100 surveyors, inspectors and construction workers, according to the company. It received federal approval last year to lay approximately 127 miles of 30-inch pipeline - along the existing 300 pipeline where possible - through northern Pennsylvania and northern New Jersey, as well as the installation of two new compressor stations and upgrades of seven others.
To connect to the larger, interstate pipelines, other companies are moving forward in Pennsylvania on what is expected to be thousands of miles of smaller pipelines to ferry gas from producing well sites. Those gathering pipelines require various federal, state or local permits to cross wetlands, streams and roads, but not federal energy regulators' approval.
The region is already crisscrossed by major interstate pipelines, but it isn't accustomed to such heavy drilling or drilling-related activity. And while the industry is credited with bringing new life to local contractors, the pipeline construction at times is generating worries over how it will affect air, waterways and land.
Jan Jarrett of the Harrisburg-based environmental group PennFuture, said she is concerned about the impact of the pipeline construction on forests, wetlands and the countless high-quality cold water trout streams that spider-web northern Pennsylvania.
Joe Osborne of the Pittsburgh-based Group Against Smog and Pollution, or GASP, said there are concerns about air pollution from the growing number of compressor stations that pump gas through pipelines. He said the stations are sources of carbon monoxide and two other pollutants - nitrogen oxides and volatile organic compounds - that contribute to the formation of ground-level ozone. The U.S. Environmental Protection Agency says that can trigger or worsen breathing problems.
"In the Northeast, we already struggle to meet the federal health-based ozone standards," Osborne said.
In many cases, new pipeline would be buried along existing pipelines in the national network.
At least one new interstate project, the MARC I line proposed by a subsidiary of Kansas City, Mo.-based Inergy LP, is getting pushback from some residents and environmental groups in northern Pennsylvania's rural Endless Mountains region.
The EPA even weighed in, writing the Federal Energy Regulatory Commission to express concerns about the potential environmental impact of the line and question whether it is even necessary.
The line, which would travel into New York, would pose the threat of pollution to 111 sensitive streams and water bodies and split 39 miles of undeveloped forest and farm land in an area that supports a robust ecosystem, high quality of life and recreation, the EPA said.
But federal regulators have found the pipeline would have "no significant impact" on the environment and recommended that it be allowed to go forward. Bill Moler, president of Inergy's midstream division, said in a statement last month the company is confident that any environmental impact has been identified and either avoided or remedied in its plans.
Certification by the Federal Energy Regulatory Commission gives a company the right to seek court approval to take property by eminent domain - a worry for some property owners in the proposed path of the MARC 1 whose families have owned the land for generations, said state Rep. Rick Mirabito, D-Lycoming. Before that happens, Mirabito said those property owners should get the satisfaction of a stronger environmental analysis of the project.
"It's one thing if we do it for the greater public good," Mirabito said. "But when it's a private company that's basically making money, getting that power, you have to make sure you do the environmental footwork first."