Hydraulic fracturing is a technique used by the oil and gas industry to facilitate natural gas recovery in underground low permeability coalbed methane wells. This operation improves the extraction efficiency of methane by creating fissions or fractures in underground rock formations, generally 5,000 – 20,000 feet below the ground surface. Highly pressurized hydraulic fracturing fluids, up to 15,000 PSI, are injected into the reservoir to force open the tiny cracks in the rock to allow for the resource to flow more readily. The hydraulic fracturing fluid used is comprised of 99.5% water and proppant material, typically sand, used to keep the fissures open. Anywhere from 50,000 – 350,000 gallons of fracturing fluids and 75,000 to 320,000 pounds of proppant material is used in a single drilling. The cause for concern, however, is the 0.5% of special purpose additives used to enhance the effectiveness of the fracturing fluid. These chemicals include potentially toxic substances such as benzene, formaldehyde, ethylene glycol, glycol ethers, hydrochloric acid, and sodium hydroxide. The danger lies in the potential for contamination of underground sources of drinking water from the 20 – 40% of the fluid that will remain underground. This is a significantly large amount given the initial amounts of fluids being injected into the ground.
In 2004, the US EPA conducted a study assessing the potential for contamination of Underground Sources of Drinking Water (USDW) due to the injection of hydraulic fracturing fluids into coalbed methane reserves. The study concluded that hydraulic fracturing posed little or no threat to drinking water so long as diesel fuel, which contains carcinogenic compounds benzene, ethylbenzene, toluene, xylene, and naphthalene was not injected into the wells. And upon the release of this study, an agreement with the service companies was reached to stop using diesel fuel as a component of fracturing fluid. Furthermore, the EPA found no confirmed cases or evidence of contaminated drinking water linked to fracturing fluids injected into underground coalbed wells.
ProPublica, an independent, non-profit newsroom that produces investigative journalism in the public interest has found many gaps in the EPA conclusion that hydraulic fracturing poses no risk to drinking water. In addition, many of the regulations are loosely enforced, especially in regards to using diesel fuel as an additive. More than 1,000 cases of water contamination across seven states have been found to have originated from a fracturing process. A recent New York Times article also documents the failure of an oilfield company failing to report fracturing violations to the EPA.
The Marcellus Shale, an underground rock formation that runs from northern Kentucky and eastern Ohio through upstate New York, is one example where hydraulic fracturing is used for gas extraction. An enormous amount of 50 trillion cubic feet of available natural gas is estimated to reside in the Marcellus Shale. This is approximately a two-year supply for the US, amounting to a value of around $1 trillion. However, much of the natural gas lies within New York City’s upstate 1,900 square mile watershed. Measures have been taken by New York State environment officials that will not allow natural gas drilling inside the watershed and within a buffer of the borderline, although, concerns still lie in the transport of contaminated groundwater. What is significant is that the state government is starting the recognize the potentially damaging effects of natural gas drilling on drinking water supplies. After several accounts of water contamination due to hydraulic fracturing, the EPA has decided to further its study in assessing the extent of damage natural gas drilling has on the environment and drinking water sources. The EPA has said that it will spend nearly $2 million on the research this year, and hopefully, this will push the progress of the FRAC Act, a House bill that would establish federal environmental controls over the process of hydraulic fracturing.