Disposal of fracking wastewater poses potential environmental problems

Wednesday, April 25, 2012 

A recent study by the United States Geological Survey (USGS) shows that the oil and gas industry are creating earthquakes. New information from the Midwest region of the United States points out that these man-made earthquakes are happening more frequently than expected. While more frequent earthquakes are less of a problem for regions like the Midwest, a geology professor from the University of Southern Indiana, Dr. Paul K. Doss, believes the disposal of wastewater from the hydraulic fracturing (or "fracking") process used in extracting oil and gas has the possibility to pose potential problems for groundwater.

Map showing significant earthquakes in the Midwest region of the United States. It was analyzed to show links between felt earthquakes and energy development.
Image: United States Geological Survey.

"We are taking this fluid that has a whole host of chemicals in it that are useful for fracking and putting it back into the Earth," Doss said. "From a purely seismic perspective these are not big earthquakes that are going to cause damage or initiate, as far as we know, any larger kinds of earthquakes activity for Midwest. [The issue] is a water quality issue in terms of the ground water resources that we use."

Hydraulic fracturing, or fracking, is a technique used by the oil and gas industries which inject highly pressurized water down into the Earth's crust to break rock and extract natural gas. Most of the fluids used for fracking are proprietary, so information about what chemicals are used in the various fluids are unknown to the public and to create a competitive edge.

Last Monday four researchers from the University of New Brunswick released an editorial that sheds light on the potential risks that the current wastewater disposal system could have on the province's water resources. The researchers share the concern that Dr. Doss has and have come out to say that they believe fracking should be stopped in the province until there is an environ­mentally safe way to dispose the waste wastewater.

"If groundwater becomes contamin­ated, it takes years to decades to try to clean up an aquifer system," University of New Brunswick professor Tom Al said.

While the USGS group which conducted the study says it is unclear how the earthquake rates may be related to oil and gas production, they've made the correlation between the disposal of wastewater used in fracking and the recent upsurge in earthquakes. Because of the recent information surfacing that shows this connection between the disposal process and earthquakes, individual states in the United States are now passing laws regarding disposal wells.

	The problem is that we have never, as a human society, engineered a hole to go four miles down in the Earth’s crust that we have complete confidence that it won’t leak.
—Dr. Paul K. Doss

"The problem is that we have never, as a human society, engineered a hole to go four miles down in the Earth’s crust that we have complete confidence that it won’t leak," Doss said. "A perfect case-in-point is the Gulf of Mexico oil spill in 2010, that oil was being drilled at 18,000 feet but leaked at the surface. And that’s the concern because there’s no assurance that some of these unknown chemical cocktails won’t escape before it gets down to where they are trying to get rid of them."

It was said in the study released by the New Brunswick University professors that if fracking wastewater would contaminate groundwater, that current conventional water treatment would not be sufficient enough to remove the high concentration of chemicals used in fracking. The researchers did find that the wastewater could be recycled, can also be disposed of at proper sites or even pumped further underground into saline aquifers.

The New Brunswick professors have come to the conclusion that current fracking methods used by companies, which use the water, should be replaced with carbon diox­ide or liquefied propane gas.

"You eliminate all the water-related issues that we’re raising, and that peo­ple have raised in general across North America," Al said.

In New Brunswick liquefied propane gas has been used successfully in fracking some wells, but according to water specialist with the province’s Natural Resources De­partment Annie Daigle, it may not be the go-to solution for New Brunswick due its geological makeup.

"It has been used successfully by Corridor Resources here in New Bruns­wick for lower volume hydraulic frac­turing operations, but it is still a fairly new technology," Daigle said.

The United States Environmental Protection Agency (EPA) is working with U.S. states to come up with guidelines to manage seismic risks due to wastewater. Under the Safe Drinking Water Act, the EPA is the organization that also deals with the policies for wells.

Oil field located in Lost Hills in California
Image: Arne Hückelheim.

Oil wells, which are under regulation, pump out salt water known as brine, and after brine is pumped out of the ground it’s disposed of by being pumped back into the ground. The difference between pumping brine and the high pressurized fracking fluid back in the ground is the volume that it is disposed of.

"Brine has never caused this kind of earthquake activity," Doss said. "[The whole oil and gas industry] has developed around the removal of natural gas by fracking techniques and has outpaced regulatory development. The regulation is tied to the ‘the run-of-the-mill’ disposal of waste, in other words the rush to produce this gas has occurred before regulatory agencies have had the opportunity to respond."

According to the USGS study, the increase in injecting wastewater into the ground may explain the sixfold increase of earthquakes in the central part of the United States from 2000 - 2011. USGS researchers also found that in decades prior to 2000 seismic events that happened in the midsection of the U.S. averaged 21 annually, in 2009 it spiked to 50 and in 2011 seismic events hit 134.

"The incredible volumes and intense disposal of fracking fluids in concentrated areas is what’s new," Doss said. "There is not a body of regulation in place to manage the how these fluids are disposed of."

The study by the USGS was presented at the annual meeting of the Seismological Society of America on April 18, 2012.

Sources

• Kevin Bissett. "Halt fracking until waste water can be properly disposed of, profs say" — The Chronicle Herald, April 24, 2012
• Jim Efstathiou Jr. "Fracking-Linked Earthquakes Spurring State Regulations" — Bloomberg, April 20, 2012
• Christopher Joyce. "Quakes Caused By Waste From Gas Wells, Study Finds" — NPR, April 11, 2012
• Associated Press. "Study ties oil, gas production to Midwest earthquakes" — Fox News Channel, April 8, 2012