When I tell friends about what industry I am working in, I often get the following question: "So what do you think about fracking?" The question alone often already indicates their bias against the technology because the term "fracking" is usually used by opponents.

Obviously, the topic has been controversial for many years now, not least because of a film called "GasLand" that showed residents living next to "fracking" sites in Pennsylvania being able to set their tap water and rivers on fire, while their properties were covered with dead animals.

But even after researching the topic for some time, I don't exactly know what I should think about it. Both proponents and opponents seem to have evidence on their side. And then there is also the confusing definition of the term "hydraulic fracturing," which means different things for different people and can lead to the same evidence being used for and against fracking at the same time (as brilliantly illustrated in this article in the New York Times).

For instance, a research study by a team under Robert Jackson from Duke University found that in a sample of 141 private drinking-water wells in an area home to about 5,000 hydraulic fracturing sites in the Marcellus shale, 4 out of 5 wells contained methane — the main component of natural gas . Yet, so far both supporters and opponents have been implicitly able to use the study to their advantage.

Fracking opponents who use the term to refer to the whole process of extracting shale oil and gas (including the drilling phase) have argued that the study proves that fracking leads to ground water contamination. In contrast, supporters who draw a strict line between drilling and hydraulic fracturing (defined as the injection of chemical-laced water and sand to break apart rock and release gas) retain that "fracking" is not the problem. As a matter of fact, even the author of the study says, "I believe it's more about the drilling than the fracking."

So fracking is not the problem? Well, it is not that easy. Putting aside this confusion of definitions, there are still hard facts that are for and against the technology. For instance, in 2011, the U.S. Geological Survey linked about 50 earthquakes in Oklahoma to fracking.

Its analysis concluded that "shortly after hydraulic fracturing began, small earthquakes started occurring, and more than 50 were identified, of which 43 were large enough to be located. Most of these earthquakes occurred within a 24-hour period after hydraulic fracturing operations had ceased."

Equally disturbing, a study by the University of Texas at Arlington found elevated levels of arsenic and other heavy metals in groundwater near natural gas fracturing sites in Texas' Barnett Shale. These metals can be contained in the so-called "flowback," the portion of fluids that flow back to the surface after being pumped into the ground.

On the other side of the spectrum, however, a well-researched report by the Massachusetts Institute of Technology concluded that only a small amount of more than 20,000 wells drilled for fracturing in the previous decade had led to groundwater contamination and that all of these incidents resulted from breaches of existing regulations. In short, if done well, fracturing is not an issue.

What to think about all that now? My conclusion is to look at the facts, to compare studies and the quality of these studies and to make your opinion.