There is much interest in drilling for natural gas in the western half and the northern half of PA., as well as upper Bucks County. Courts have ruled that municipalities cannot regulate it - it can even occur in the middle of homes.
The following is the text and audio of a great article from NPR about what can happen after a natural gas boom. It is about how natural gas drilling has moved into urban areas in Texas. As a result, companies are using condemnation powers to force through natural gas pipelines through residential yards. These pipelines are not "odorized" so they do not generate a smell when there is a leak. There also has been much construction of compressor stations and other mechanisms, one of which recently exploded in a city.
The natural gas is often a mile below the surface. That requires unusually heavy drilling equipment that rips apart public roads. There also can be storage tanks for the gas in the middle of homes.
http://www.npr.org/templates/story/story.php?storyId=93300400