Fracking in North Carolina could carry extra risks
North Carolina’s geology will require extra precautions
05/22/2012 6:00 PM
05/22/2012 9:45 AM
North Carolina’s flirtation with fracking is increasingly looking like the real thing, with Republican lawmakers poised to pass sweeping legislation this summer that would lead to drilling for natural gas.
The state may have just a fraction of the enormous natural gas reserves found in Texas and Pennsylvania. But fracking here will likely entail greater risks to drinking water supplies and may require special measures not used in other states.
North Carolina’s natural gas reserves are much closer to groundwater than in other states, and the rock in between is not watertight and could permit potent fracking chemicals to work their way upward and contaminate the aquifers, state regulators say.
State officials will take at least several years developing safeguards to protect residents, farm animals, crops and natural habitats from the hundreds of chemicals used in the process of fracking. The chemicals – used to kill bacteria, prevent well corrosion and to thicken fracking fluids – for years had been regarded proprietary and kept secret.
In response to public pressure, however, the names of those chemicals are now being divulged in other states and have been shown to contain carcinogens and other toxins that can damage the nervous system, kidneys and liver when mixed in high volumes. Accidental spills and blowouts have been linked to fish kills, livestock deaths and other complaints.
“It’s hundreds of thousands of pounds of chemicals per well,” said Robert Jackson, a professor of environmental science at Duke University. “It will have to be done safely.”
In fracking – shorthand for hydraulic fracturing – benzene, methanol and other chemicals are mixed with water and pumped underground at high pressure to shatter shale rock and to flush the gas trapped inside. Up to 2 percent of the fracking fluid is made up of a chemical mixture.
Fracking is not legal in North Carolina, but legislation is slated to be introduced as early as Monday that would overhaul the state’s oil and gas laws.
“When it’s done right, it will be composed of all the necessary rules and regulations,” said state Sen. Bob Rucho, a Mecklenburg County Republican whose bill would legalize fracking by mid-2014. “You’re talking close to 9,000 pages.”
Rock that could leak
North Carolina’s environmental regulators have urged lawmakers to pass one of the nation’s strictest disclosure standards, requiring the industry to reveal all chemicals and combinations used in the fracking process, with the exception of trade secrets. The state Department of Environment and Natural Resources, in a 484-page study issued last month, also urged lawmakers to ban the use of diesel, a toxic additive considered particularly dangerous to drinking water.
The agency also warned that fracking chemicals pose special risks here because of the state’s unusual geology.
“The unique geology and hydrogeology of the Triassic Basins of North Carolina suggests that there is a greater risk of groundwater contamination from oil and gas operations here than may be present in other shale gas plays,” the agency said.
Shale gas deposits are typically separated from groundwater by a barrier of ancient rock formations, which in the case of the Marcellus Shale in Pennsylvania measures nearly two miles thick.
That means that as long as well shafts are well-constructed and properly reinforced – which has not always been the case – chemicals pumped underground should not leak through the well shaft and “migrate” upward to contaminate drinking water.
North Carolina is different. For one thing, the distance between the state’s shale gas reserves and drinking water is not as vast, less than a half-mile in some areas, the state report indicates.
What’s more, the sedimentary rock separating the gas from the water may not form an impermeable barrier if disturbed by underground fracking explosions, said assistant state geologist Kenneth Taylor.
“Something could seep into the water,” Taylor said.
The area under Lee, Chatham and Moore counties, where the shale gas is believed to be concentrated, is punctured throughout with massive slabs. These “dike swarms” were once streams of molten magma that surged upward under high pressure millions of years ago and then solidified. The slabs, measuring as much as 150 feet thick and several miles across, break up the solidity of the barrier between the gas and the water.
This means that wells drilled in North Carolina will likely have to be sealed with cement and multiple layers of steel from top to bottom, Taylor said, rather than relying on the minimum standard of 50 feet of sealing at the bottom. The minimum standard is recommended by the American Petroleum Institute, the oil and gas lobby.
Furthermore, it would be unsafe to drill wells and frack near the slabs because that could prompt fracking chemicals injected below to flow into drinking water above. Determining a safe drilling distance will require scientific study, Taylor said.
The state study says that accidental chemical spills at the surface are almost inevitable but can be limited with strict requirements and controlled with mitigation plans. Those specifics would fall under the second phase of agency’s research, a multimillion-dollar project that has not yet been funded.
The fracking industry has long said that its chemicals are unfairly demonized.
“A lot of these chemicals are chemicals people come into contact with in their everyday lives,” said Simon Lomax, research director at Energy In Depth, an industry organization in Washington. “The point is they are to be used as directed.”
Some are used in household cleansers and as food additives, he said.
Under intense scrutiny, the fracking industry has markedly improved its safety record since 2008, according to a study issued last week by the University at Buffalo’s Shale Resource and Society Institute. Incidents were down by more than half with more regulation.
The study examined nearly 3,000 violations from nearly 4,000 natural gas wells in Pennsylvania over four years. Only 25 of those were major accidents, such as spills, well leaks, blowouts and water contamination, mostly caused by human error or negligence.
The report concluded all 25 of the mishaps could have been prevented or controlled by measures under consideration in New York, which is under a fracking moratorium as it develops laws and rules.
“It’s like school speed zones, 20 miles per hour,” said one of the Buffalo report’s co-authors, Timothy Considine, an economics professor at the University of Wyoming.
“If there’s a cop parked out there, where everyone can see, it maintains compliance. Vigilance keeps these companies on their toes.”
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