Hydraulic fracturing — less formally known as fracking — has drawn the ire of many environmentalists due to earthquakes and other issues, despite its positive contribution to United State’s shale oil boom.

For those in need of a quick refresher, fracking is a high-pressure drilling method that recovers oil and gas from shale rocks deep beneath the Earth’s surface, injecting water, sand, and chemicals into the rock to release it.

Criticisms include the method’s potential to contaminate groundwater, and most recently, such drilling’s contribution to earthquakes. Earthquakes in particular are a cause for concern in middle America, which has experienced a huge increase in seismic activity in recent years.

Here’s what to know about how fracking is quite literally shaking up America, what it means, and if things are likely to change in the future.

Fracking-Induced Earthquakes: How they happen

Man-made activities have been known to cause earthquakes in the past, so it isn’t so much of a surprise that fracturing rocks deep within the Earth’s crust could potentially do so as well.

During the fracking process, long, narrow fractures are produced in the shale rock formation. The resulting “microseismic” events are typically less than magnitude -2 or -3.

It’s only been recently that the link between larger earthquakes and fracking has been scientifically determined: in January 2015, researchers found that a magnitude 3.0 quake (felt by humans) in Ohio coincided with fracking in a nearby gas well on a previously existing fault line.

Despite the invasive process of fracking itself, research strongly suggests that what’s actually inducing seismic activity is likely the post-fracking injection of wastewater into deep disposal wells.

This process, though regarded as the safest and most cost-effective disposal method, aggravates the faults from within, producing earthquakes that are growing in frequency, size and strength.

Where is it happening?

Asides from Ohio, states like Oklahoma, Texas, Colorado, and Arkansas have also experienced an increase in earthquakes that coincide with fracking.

In Oklahoma, for example, the frequency of magnitude 3.0 quakes has skyrocketed from just one and a half per year, to 585 in 2014 alone — more than any state with the exception of Alaska.

Oklahoma’s government even officially accepted the scientific consensus that the earthquakes there were indeed linked to fracking — or more specifically, the wastewater disposal associated with it.

Now, evidence has it that earthquakes in the Dallas, Texas region — which had only experienced one recorded earthquake in the 58 years before 2008 — are “most likely” caused by the post-fracking wastewater process.

Since 2008, the northern Texas region experienced 140 earthquakes, most of them small. But that doesn’t rule out the possibility of larger, more damaging quakes, as was evidenced by a 5.7 magnitude quake in Oklahoma, the largest linked to injection wells, which damaged 14 properties.

What’s next for fracking?

With all the bad press, not to mention doubts over economic sustainability, “Will fracking survive?” The Atlantic Council’s Global Energy Center tackled this question, and it’s certainly one worth asking.

As far as earthquakes dissuading fracking, it’s unlikely they will be its undoing — experts are confident in fracking’s future, but are more worried about the effect of low oil prices than environmental concerns.

As oil prices plummet, the fracking boom in America is expected to slow down, and while some providers may shut down, others will have to become more cost-effective.

Will an alternative wastewater disposal method play into this, thus reducing the likelihood of quakes? Probably not until a less expensive process is developed.

It’s worth noting that fracking, though controversial and certainly in need of more research and attention, has benefits as well: economically, as it lowers the price of energy and utilities, creates jobs, and saves consumers $150 a year.

The question is whether or not getting shaken up in the process — along with a wealth of other environmental concerns — is worth the other perks.