Oil and gas drillers have been tapping into shale deposits beneath eastern Ohio for years now. It's a similar story all over the country.
But researchers, regulators, non-profits and even people working in the industry still have a lot of questions about how fracking will affect the environment.
Alan Krupnick, director of the Center for Energy Economics and Policy at environmental think tank Resources for the Future, surveyed these stakeholders. Speaking on The Sound of Ideas, he said everyone says they're concerned about whether shale drilling contributes to climate change.
KRUPNICK: "There is a major concern about methane -- fugitive methane, it's called. It's methane that leaks out of the wells themselves or pipes, and processing facilities. That has a very great ability to warm the atmosphere."
He says they also say they're concerned that fracking waste might contaminate surface water.
The U.S. Environmental Protection Agency is in the process of studying whether fracking pollutes groundwater. It's a big new step for the EPA into the fracking debate.
BRISKIN: "This is the first time that EPA has looked at the potential impacts of hydraulic fracturing."
Jeanne Briskin with the EPA was at Case Western Reserve University to outline the agency's research so far. EPA researchers are collecting data from wells at shale deposits around the country. They're also performing case studies at a few sites that have already been fracked, and some that are about to be. Briskin says the EPA wants to know whether any step in the fracking process pollutes drinking water.
BRISKIN: "Does acquiring large volumes of water for hydraulic fracturing have an impact on drinking water resources' quality? We're interested in the process of making the hydraulic fracturing fluid. If there are some spills, might that cause an issue?"
And she wants to know how drinking water is affected when drillers pump fracking fluid into the ground, and when that fluid comes back up.
Another question still being asked -- what chemicals are in fracking fluids? Companies consider some of these chemicals to be trade secrets. Briskin says the EPA has disclosed more than 1,000 chemicals used in the fracking process, and is working on cataloging them.
Mark Zoback, a professor of earth science and geophysics at Stanford University, says the chemicals should be disclosed.
ZOBACK: "Just put it all out there. There's nothing to be afraid of. And let's get rid of...this unnecessary proprietary concerns."
Zoback also said in a presentation as Case Western Reserve that scientists should be monitoring seismic activity that could be linked to fracking wastewater injection -- though he said on The Sound of Ideas that it's not common for fracking or wastewater injection to cause significant earthquakes.
And still other questions remain. This year, Devon Energy announced it would leave Ohio -- raising the question of whether the shale boom will deliver the sustained economic prosperity that is often promised.
Steve Percy, the dean of the Monte Ahuja College of Business at Cleveland State University, says it's too early to know.
PERCY: "There's plenty of market for the gas, but there's lots of gas. So with thousands of cubic feet of gas moving to supply that market, the price is going to drop. So with that happening, drillers are pulling back on their current activity."
The industry will likely continue drilling in Ohio, but clear answers to some of these questions still could be some time away. The EPA plans to publish the draft results of its study next year, with the final study slated to be out in 2016.
