Fracking can never be done safe, at least not with today's technology. You are drilling russian roulette mode, sometimes it's safe but mostly it's not.
When a company has drilled a few hundred wells in a field, with all the electric log analysis, reservoir simulations, and production decline analysis, I believe that it's safe to say that the oil company has a pretty darn good idea what's happening subsurface.
Companies are simply making guesstimates of what will happen when they pressurise formation and, where the fractures will go and how it will affect ground water at various depths.
Ever heard of microseismic monitoring? Oil companies want to maximize the contact of hydraulic fractures in the pay zone and minimize growth into zones directly above and below the pay zone (because the horsepower, water, and proppants end up getting wasted in non-productive zones). Microseismic monitoring has been performed on literally thousands of shale wells. There are other similar technologies, such as surface and subsurface tilt-meters that measure rock deformation (these tilt-meters are also used on some busy bridges to monitor strain on the steel beams, protecting vehicle traffic in high-population areas). Microseismic data has shown time and time again that shear events from hydraulic fracturing operations may be detected a few layers of rock, around 300-500 ft at most, above the pay zone. So a horizontal section of a well drilled at around 7,000-feet deep will not get nearly close to fracturing into an aquifer. Perhaps in a case where a drilled to 3,000 feet with an acquifer at 2,500 feet would it be possible to propagate a fracture to the aquifer, but that's not where any of the shale zones are at.
Will it affect nearby wells, they don't know and they don't give a fuck.
You don't drill a $7 million well and not care about how one well affects another, or whether your fractures are optimized in your pay zone.
They paid their lobbyists to influence Darth Cheney to write laws to protect frackers from the frackers murderously greedy activities.
The so-called "Halliburton loophole" was done to keep an over-reaching EPA from regulating apples and oranges cases. For decades, the EPA did not regulate hydraulic fracturing operations as "hazardous waste disposal", and rightly so. The purpose of hydraulic fracturing is to create fractures, not dispose of hazardous waste. At some point in the early 2000's, a bureaucratic at the EPA, not understanding the process, decided to treat hydraulic fracturing the same as waste disposal. These are not nearly the same things. But of course, the fact that Cheney helped reverse this error is interpreted by some people to be an act of greed.
The reality is there is no technology currently available to forecast what will actually happen when you try to turn rock formations into massive soda fountains, none at all, it is a straight up guess.
Totally, absolutely false. Sure, there is still some uncertainty to what *exactly* goes on subsurface. But there *is* a lot of technology out there that oil companies and the oil service industry employs to understand hydraulic fracturing. 2D hydraulic fracture equations were developed in the 60's, and 3D computer simulators in the 80's. Reservoir simulation software. Petrophysical analysis (electronic well logs and core sample analysis). Production decline analysis. Hydraulic fracture treatment pressure-matching, mini-frac analysis, etc. There are a *lot* of different techniques being employed to try to understand hydraulic fracture growth in hydrocarbon-bearing formations. There is also millions of research dollars being spent in universities to advance the science. There are a multitude of conferences every year where engineers and scientists in the industry go to peer-review each other's works and advance their understanding of fracture behavior. This is not some hidden process that gets applied haphazardly.
Pretty much a safe bet for the fracker they will likely get a big profit as for everyone else around that location, let's be honest, as far as the frackers are concerned luck of the draw 'Fuck Em'.
Safe to say that if an oil company's well end up fracturing into a water zone (even a salt-water zone, which are much closer to hydrocarbon zones than freshwater acquifers), that the oil company is sure as heck not making a profit on that well. Water wells do not oil companies a profit make.