Weighing potential costs of hydraulic fracturing

The recent expansion of hydraulic fracturing across the nation has set off a debate among oil and gas industry officials and conservationists and environmental scientists.

During a recent House Space, Science and Technology Committee hearing, Congressman John Sarbanes (D-MD) outlined the points of contention: “You have one group that’s got long experience with hydraulic fracturing [contending] it’s very safe” and “you have another group that’s new to it and is having to analyze the potential of risks associated with it.”

Hydraulic fracturing, commonly known as “fracking” involves using high-pressure injections of water, chemicals and sand to open cracks that release gas trapped in rock deep underground. Advances in fracturing technology have led to a dramatic surge in gas extraction nationwide. The U.S. Energy Information Administration (EIA) estimates that the United States has 2,119 trillion cubic feet of recoverable natural gas, about 60 percent of which is “unconventional gas” stored in low permeability formations such as shale, coalbeds, and tight sands. In 2010, production of this “shale gas” doubled to 137.8 billion cubic meters, up from 63 billion cubic meters in 2009. A Pennsylvania State University study stated that deployment in 2008 of hydraulic fracturing technology in the Marcellus Shale region generated more than $240 million in state and local taxes for Pennsylvania, 29,000 jobs and $2.3 billion in total economic development.

The oil and gas industry falls into the camp of those who contend that decades of practice show that hydraulic fracturing is important economically and poses no discernable threat to public health or the environment. In the other camp are conservationists and some researchers who say that fracking could pose a risk to drinking water supplies.

During the recent congressional hearing, the committee’s majority Republican members repeatedly asserted that the Environmental Protection Agency’s $12 million study on the safety of hydraulic fracturing is wasting taxpayer dollars. “The study intends to identify the potential impacts of hydraulic fracturing on drinking water without ever taking into consideration the probability that such an effect may occur,” said Chairman Ralph Hall (R-TX).

A key part of understanding different views of the potential risks of “fracking” is how it is defined. Many in the oil and gas industry use the term to describe not the drilling process but, more specifically, the completion phase where chemical-laced water and sand are blasted underground to break apart rock and release gas. Companies assert it is a safe practice since so far there has been no indication of hydraulic fracturing fluid rising above the mile or so of rock layers to reach drinking water aquifers.

Others outside the industry typically view fracturing and drilling as interconnected. Consequently, they maintain that the impacts of drilling, which precedes the actual “fracking” should also be taken into account when looking at potential negative impacts, with some contending that the drilling carries greater risk.  A recent study from Duke University suggests that gas drilling can cause methane gas to leak into drinking water and sometimes the air in people’s homes. The study suggests that approximately 44 million Americans rely on a private water supply that is typically sourced from shallow aquifers.

The Duke study also notes that a wide array of factors can potentially lead to contamination from wastewaters associated with hydraulic fracturing including, “the toxicity of the fracturing fluid and the produced waters, how close the gas well and fractured zone are to shallow ground water, and the transport and disposal of wastewaters.” It also says that despite precautions by industry, water contamination can still occur through “corroded well casings, spilled fracturing fluid at a drilling site, leaked wastewater, or, more controversially, the direct movement of methane or water upwards from deep underground.”

Methane, which comprises 90 percent of shale gas, is not regulated in drinking water as it does not alter the color or taste of water, nor does it affect its potability. The Duke study found that methane levels were 17 times higher in water wells near gas drilling operations above the Marcellus and Utica shale gas formations in Pennsylvania and New York than those farther than 3,000 feet away. The study noted that outside extreme cases of explosion, flammability and asphyxiation, methane is not typically viewed as a health hazard in low concentrations.

According to the New York State Water Resources Institute at Cornell University, the New York Marcellus Shale is located about 3,000 – 5,000 feet below the surface, but it is possible that cracks in the rock may occur at depths of less than 500 feet, which could lead to contamination of drinking water. The Duke study noted that a single hydraulic fracturing well can, over the course of one month, produce millions of gallons of wastewater that contain pollutants unsafe for drinking water and the surrounding environment. These pollutants can include “formaldehyde, boric acid, methanol, hydrochloric acid, and isopropanol, which can damage the brain, eyes, skin, and nervous system on direct contact,” as reported in the study.

The Duke study concludes that while hydraulic fracturing has not been proven to have the obvious detrimental impacts associated with coal burning or mountaintop mining, additional scientific research would serve to both increase public confidence and address lingering concerns. Society has a consistent predilection for waiting until public health is already severely compromised (often involving fatalities) before addressing a problem. In light of some of the red flags being raised on this issue, it seems sensible to avoid waiting for potential danger to become a clear and present danger.

Perhaps it all comes down to whether a $12 million study that, at the very least, will inform and perhaps improve how we extract natural gas is worth what could be the far higher price of coping with adverse environmental and public health impacts.

Photo Credit: arimoore

Author: Terence Houston

Science Policy Analyst for ESA.

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1 Comment

  1. Dear Terence Houston,

    The characterization of the information found at the NY State Water Resources Institute is misleading. The page you reference does indeed acknowledge the risk to groundwater arising from issues with the cementing and well construction near the surface. However, this is primarily a well drilling issue, and is not related to the hydraulic fracturing procedure.

    The page goes on to explain that the New York City DEP has expressed “concern” regarding the connection of deep fractures with near surface groundwater. I would encourage you to reference them in this regard. It is our understanding at WRI that direct contamination of groundwater as a result of hydraulic fracturing, insofar as such contamination may be caused by “cracks in the rock,” is extremely unlikely.

    Rather than dwell on one aspect of the shale extraction issue that has little scientific credibility (ie. hydraulic fracturing contaminating water via enormous vertical cracks), we feel it more beneficial to focus on and discuss the numerous other significant and credible concerns associated with this development. Perhaps our website does not convey this clearly enough. We will try to improve that.

    It is clear that, as you say, there will be some negative environmental and public health impacts. It is also clear that our energy demands are staggering, and that shale extraction will lead to economic benefits for some. How one feels about this issue likely comes down to whether one perceives themselves as losing or gaining, and also to how one identifies with and assigns value to their environment, their community, and their livelihood. It is difficult and contentious. I hope that future dialogue involves both “sides” of this debate acknowledging this complexity. Unequivocal positions are seldom correct and leave no room for discussion or understanding. We can do better.

    Brian G Rahm
    NYS Water Resources Institute

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