Newswise — A professor at The University of Texas at Austin's Cockrell School of Engineering said the risks incurred during hydraulic fracturing are low when compared to the risks of energy production from any other energy source and that some commonly believed notions about the gas extraction process are incorrect.

While hydraulic fracturing has been used since the 1950s, the controversial process has received heightened attention in recent years as oil and gas companies have expanded their operations into "shale plays," geologically tight formations containing vast natural gas resources. Recent documentaries like "Gasland" and "Haynesville" have further heightened public interest in fracturing, and earlier this summer Texas lawmakers passed groundbreaking legislation requiring oil and gas operators to publicly disclose the specific chemicals used in hydraulic fracturing.

"Should these chemicals be disclosed? Absolutely," said Dr. Mukul Sharma, a Cockrell School professor who holds the "Tex" Moncrief Chair in the Department of Petroleum and Geosystems Engineering. "But to claim hydraulic fracturing is a toxic mix of things is incorrect. All of these materials have been used in oil and gas wells for the past 100 years."

Also known as "fracing," the process creates fractures in shale formations to extract natural gas that was once thought unrecoverable. Now, combined with horizontal drilling, the process has transformed traditionally unproductive deep shale formations and led to an energy revolution over the past decade that is credited for the production of a significant and increasing proportion of domestic oil and gas. Sharma said natural gas is a cleaner burning fuel, significantly less expensive than oil and provides a domestic source of energy that creates jobs and tax revenue to states and royalty income to landowners.

But opponents of the process have raised safety and environmental concerns about fracturing. Chief among them are that it contaminates groundwater, depletes valuable water reserves and can cause earthquakes.

Sharma's presentation June 27 to faculty and students in the department's Summer Research Internship program addressed these concerns — some of which he said are real and some perceived — along with other facts and myths surrounding hydraulic fracturing.

In reference to concerns about the amount of water used for the process, Sharma said municipal water-use in the Barnett Shale — a top natural gas-producing formation in north Texas — is 323 billion gallons. The water used for fracturing in the same area is only about 2.7 million gallons per well.

"To say we're going to consume all of the water resources in the region is fear mongering," he said.

Sharma said the process does cause earthquakes but their magnitude is smaller than an earthquake that occurs when a truck drives down a road, rarely producing any damage to buildings on the surface of the Earth.

"On the Richter scale, they would be negative or put another way, one million times smaller than a typical California tremor," Sharma said.

He also praised recent legislation in Texas that, beginning in 2012, will require oil and gas operators to disclose the chemicals that they inject into the ground during hydraulic fracturing. Oil and gas companies lobbied against the legislation, arguing that it would disclose trade secrets to competitors.

Sharma said people should "know what’s going in the ground," but he said he hopes the new regulations are not onerous to the point that they cause the process to slow down.

"That's the balance we have to strike, and only time will tell whether we have achieved this balance," he said.

He also added that most shale gas extraction uses water and polyacrylamide, a non-toxic polymer that helps reduce friction in the wellbore.

Fear of groundwater contamination from hydraulic fracturing has been heightened, most notably by the 2010 "Gasland" documentary, which interviews a resident in Pennsylvania who is able to light his tap water on fire. The resident said nearby gas drilling was to blame.

Sharma said such claims in the documentary are misleading because natural gas has been known to seep in water wells decades before hydraulic fracturing was ever used. He said an example of such occurrences is western New York's Eternal Flame Falls, a natural waterfall over shale that emits natural gas from deep inside the Earth and produces flames when lit.

Sharma said more than one million wells have been drilled with hydraulic fracturing and, to date, there are no documented cases of groundwater contamination resulting directly from fracturing.

"If this was a pharmaceutical drug trial this would be a stupendous success," he said.

"Can you contaminate ground water? Yes," he said. "But the fact that we've had a long history of doing this and we haven't had any cases where this has happened indicates to me that if the engineering is done properly and we take basic precautions, we can avoid this issue."