Fracking: what's the big deal?

Fracking is talked about a lot nowadays -- mostly heatedly and almost always in a binary fashion (YES/Good or NO/Bad). What is fracking all about?

When we think of drilling for some liquid substance, what first comes to mind is something similar to putting a straw into an underground reservoir. Some may include the idea of a bunch of very wet sand, where the liquid is dispersed through the area but freely available.

Both of these were probably true for the earliest wells. A hole was pierced in the soil and it either hit an area of liquid (water, oil, also natural gas -- which is not liquid but, in this case, has the important properties of a liquid) or it was able to find an area that the liquid could collect in from the surrounding area.  For water, this is called the aquifer. For water and other "liquids" (including natural gas), this ability to collect from the surrounding area is making use of a quality called "permeability" -- the ease of movement of liquids/gases through solids.

Pool are pools. It is a matter of finding them and using them. Permeability decreases as the area gets deeper because of the weight of the earth above. Greater pressure lowers the permeability of the surrounding area.

As we make use of more of our natural reservoirs of water, oil, and other liquid/gas resources, it is harder to find easy-to-use locations. Isolated pools become deeper (or underwater) and smaller (making them less economically possible to exploit). Natural permeability occurs more towards the surface and is harder to find. Thus, there is the desire to go where we have not gone before (national parks, wilderness, and beneath beds of water) and to promote artificial permeability.

Finally, you say, we get to fracking. Fracking is the process of breaking up the surrounding rock and creating permeability where none (or little) existed before. Early fracking mainly used explosives to break up the ground underneath. Although it usually worked, it was not very effective because of the irregularity of the fissures (or cracks) created and because, if it was deep, those cracks were likely to close back up from the pressure.

The modern practice of fracking usually involves hydrologic pressure. A liquid (often water) is injected into the well under great pressure and this causes the surrounding area to crack. Additives are put into the liquid to help keep the cracks open (thus, allowing permeability) after the pressure is removed. One method is called "acid etching" where an acid makes "grooves" in the cracks as they expand leaving little furrows when pressure is removed. This is done to make access to reserves more possible.

There are two primary problems with fracking. First, it requires a lot of liquid to achieve fracking. While that didn't use to be looked at as a problem -- with global climate change and uncertain icepacks and rains and overused aquifers it is quite a problem nowadays. I don't know the exact proportion of water to newly accessible liquid (you wouldn't normally use this technique for water wells, obviously) but there is a lot of water used. In addition, the additives put into water may not be either environmentally or health beneficial and those additives will find their way into the surrounding area.

The second problem is that the cracking of the earth is indiscriminate -- it does not JUST allow the desired liquid/gas to pool together. If there are pockets of water and gas or oil nearby, the fracking is likely to allow the mixing of such -- and causing health and environmental problems with use of the water.

The first problem might be addressable with new techniques (air fracking, perhaps, with environmentally safe additives) but the second problem is inherent to the process.

The only real method of eliminating the need for fracking to access dwindling natural reserves is to use alternate energy/base material sources.

What are your thoughts about fracking?