Hydraulic fracturing, more widely known as fracking, is a process in which a fluid is pumped at high pressure into a geologic formation to break up the rock, and release oil or gas trapped within. The oil or gas is subsequently siphoned out, along with any recovered fracking fluid (water combined with chemicals such as isopropanol). Frequently, these geologic formations are shale formations, and it is shale gas (an increasingly important form of natural gas) that is being extracted. Fracking has been largely embraced as helping the US on its way to energy independence, and shale gas is considered by many to be a cleaner-burning alternative to coal and other fossil fuels. However, there are numerous qualms with the practice.

Workers inspect a natural gas valve at a fracking site in Pennsylvania’s Marcellus Shale region.

Check-out this awesome site, which guides you through the fracking well and all the concerns of the practice.
Fracking threatens public health and the environment through the following ways:
First, fracking pollutes groundwater; methane concentrations are 17x higher in wells near fracking sites (relative to normal wells).
Second, the process consumes vast quantities of water, upwards of 200 trucks per well – much of which cannot be recovered.
Lastly, fracking has been found to cause earthquakes in different parts of the country.

If you’re more interested in this issue, you may want to check out a great episode of The Colbert Report about fracking from last summer or the sources for this article listed wells n
Environmental Protection Agency, “Evaluation of Impacts to Underground Sources of Drinking Water by Hydraulic Fracturing of Coalbed Methane Reservoirs Study”. Published in 2004.