Fracking is a technique of fracturing rock with a pressurized liquid; the veins or fractures formed in the rock allows gas trapped within to escape. This technique is what allows natural gas to be extracted from shale, a particular type of rock formation. Pennsylvania is home to one of the largest formations in the United States; the Marcellus Shale.
Fracking is what allows natural gas to be produced so cheaply in America, but it also causes a huge amount of waste in the form of contaminated water, sand, and other chemicals. The handling and disposable of this waste is one of the main environmental concern with this hydraulic fracturing process.
A Coast Guard proposal is suggesting the use of barges, which can carry up to 10,000 barrels of waste, as a means of transporting the fracking by-product to disposal sites. A Pennsylvania commission recently put together a report that shows the various types of dangerous chemical already being transported down PA waterways by barges.
Corporate gas drillers point the barges safety record, averaging only seven major spills per year, which is much less than trucking, as a positive.
Environmentalist point to that same stat of seven major spills per year, which is higher than the railroad average, as a negative. These spills could now occur along the PA waterways and rivers; giving this process another chance to potentially contaminate fresh water and drinking supplies in the state.