Monday, December 12, 2011

Environmental Impacts from Fracking

The oil and gas industries’ ability to pull, push or otherwise draw hydrocarbons from the earth has exceeded our knowledge of geology and groundwater and gotten ahead of our regulations which were created for traditional oil and gas wells. In the lingering Texas drought the oil and gas industry finds itself competing for the millions of gallons of water necessary to hydro fracture a well with other users -towns and ranches. In some areas ranchers are selling water rights while in other areas drillers are being limited in how much water they can draw from the aquifer. The portion of the water used to hydro fracture a well that can be recovered and reused for other fracking jobs is determined by flowback and how the water is treated or disposed of. Flowback from fracking is determined by geology and the amount of water absorbed by the rock formations, before the rest needs to flow out of the well to allow the released gas to flow.

In Texas groundwater is being used to frack wells at an unsustainable rate. In Texas groundwater belongs to the landowner and governed by the rule of capture, which grants landowners the right to capture the water beneath their property. The landowners have a right to pump and capture whatever water is available, regardless of the effects of that pumping on neighboring wells. Any single landowner in a watershed could in effect sell all the groundwater quite legally taking their neighbor’s water. Groundwater should not be used beyond its recharge rate or ultimately it will be depleted leaving communities without adequate water to support them.

The water that is absorbed into rock formations may change the formations in ways we do not understand. Though the water in the hydro frack is exempted from the clean water act (by a 2005 act of congress), the flowback is not and must be disposed under state regulations. The flowback water itself is a problem, it contains “proprietary” chemicals and contaminates from the geological formation. Researchers of the University of Texas at Austin were part of a team of researchers who studied a series of small earthquakes that struck near Dallas, Texas in 2008 and 2009, in an area where natural gas companies had used fracking. The epicenter of the quakes turned out to be about half a mile from a deep injection disposal well under the Dallas-Fort Worth International Airport used to dispose of the fracking fluid. The largest earthquake of the series measured 3.3 on the Richter scale, a very small earthquake. In a study that was published in the Bulletin of the Seismological Society of America, the researchers also reviewed records from US Geological Survey seismic-recording stations in Oklahoma and Dallas. It was concluded by the researchers that the fracking did not cause the earthquakes, but there seemed to be a relationship to the deep well injection of the fracking fluid to the earthquakes.

For years the US Geological Survey has been studying the factors that impact the response of groundwater wells to earthquakes, including the magnitude and depth of the earthquake, distance from the epicenter, and the type of rock that surrounds the groundwater. The depth of the well, whether the aquifer is confined or unconfined, and well construction also influence the degree of water-level fluctuations in wells in response to seismic waves. It has been suggested that some aquifers may even act as resonators, which may amplify the response. Even a small earthquake is not without consequences to the groundwater in the surrounding area. Fracking may also have impacts on nearby water wells. Water injected into a previously dry formation may act as a resonator or lubricant to allow the formation to slide.

Local geology determines the danger of fracking to the water table. In Wyoming where the water table is deep and the gas shallow the drinking water has been impacted. The Environmental Protection Agency, EPA, announced last Thursday that glycols, alcohols, methane and benzene found in a well the EPA drilled to the drinking water aquifer in Wyoming within the Pavillion field were consistent with gas production and hydraulic fracturing fluids and likely due to fracking. The oil company responsible for these wells claims that the results are inconclusive because methane can naturally seep into groundwater wells that provide drinking water. This is a rare occurrence that is usually confined to deeper water wells in the coal-producing areas, but these were deeper wells in a coal producing area. Benzene also occurs in nature, but I can find no instances where benzene was introduced into drinking water by purely natural action; though it could have been introduced into the water by previous generations of oil and gas development. Benzene, glycols and alcohols were all common substances in fracking fluids. In 2004 when EPA first looked at hydro fracking they coordinated a voluntary agreement with the three largest fracking contractors (Halliburton, BJ Services, and Schlumberger), to stop using diesel fuel in hydro fracking. Until 2004 diesel had been commonly used in hydro fracking coal bed gas and the deeper shale gas. Diesel contains benzene, so it seemed likely to the investigators they were introduced by fracking.

EPA constructed two deep monitoring wells to sample water in the aquifer, and tested private and public drinking water wells in the community. The samples were consistent with chemicals identified in earlier EPA results released in 2010 and are within established health and safety standards for most substances, but not for benzene. Sampling found up to 246 micrograms of benzene per liter of water was found in one well, far above the safe drinking water standard of 5 micrograms per liter. The geology of Pavillion, Wyoming is unusual for shale gas formations. The shale is much shallower than in the Haynesville shale and the Marcellus shale, though there is a shallow area of the Fayetteville shale. The fracturing in Wyoming took place both within the water table and a few hundred feet below the drinking water aquifer close to drinking water wells.

In hydraulic fracking on average 2-5 million gallons of chemicals and water are pumped into the shale formation at 9,000 pounds per square inch and literally cracks the shale or breaks open existing cracks and allows the trapped natural gas to flow. While geologists and engineers believe that in hydraulic fracturing the intervening layers of rock prevent a fissure from extending into the water table, they base this on the “typical” geology where there are thousands of feet between the water table and the fracking location and does not account for any potential impacts on the hydraulic balance in a watershed. The problems seen in drinking water wells near hydro fracking jobs typically occur when fracking fluid seeps into drinking water wells through improperly sealed or abandoned drilling wells (a large number of the problems have occurred in older coal bed areas). However, in Pavillion the groundwater is within a few hundred of the gas reserves the groundwater is more easily directly impacted by fracking. In addition, there had been previous development of the oil and gas resources opening the possibility for improperly abandoned or sealed wells. In Pavillion, Wyoming they used hydro fracking within the water table near the drinking water wells. It is not at all surprising that they contaminated the water supply. What is surprising is that the business and the regulator allowed this to happen. They did it without thinking about the potential consequences because it was legal.

The oil and gas industry has outpaced regulators, knowledge of the consequences and it seems common sense. It is essential to determine the vertical and horizontal separation that is necessary to protect the drinking water aquifers from fracking and what impact new rounds of hydraulic fracturing can have on previous developed areas with old abandoned wells before watersheds are destroyed. Then increase oversight to ensure that this separation is maintained (despite inevitable requests for waivers), improve well-design requirements and ensure their consistent implementation and require the appropriate treatment and recycling of drilling waste water. Use of waste water treatment plants that were designed to address biological solids to treat millions of gallons of water used for hydraulic fracturing or ponding the waste is short sighted and imprudent. The deep well injection commonly used in Texas may have consequences beyond small earthquakes.

Drilling requires large amounts of water to create a circulating mud that cools the bit and carries the rock cuttings out of the borehole. After drilling, the shale formation is then stimulated by hydro fracking, using 2-5 million gallons of water. For gas to flow out of the shale, all of the water not absorbed by the formation during fracking must be recovered and disposed of. Though less than 0.5% by volume, the proprietary chemicals represent 15,000 gallons in the waste water recovered from the typical hydro fracking job. The chemicals serve to increases the viscosity of the water to a gel-like consistency so that it can carry the propping agent (typically sand) into the fractures to hold them open so that the gas can flow. Determining the proper methods for the safe disposal of the large quantities of this fracking fluid that may also contain contaminants from the geological formation including brines, heavy metals, radionuclides and organic contaminants and monitoring the impact from this disposal must also be done. The impact of so much waste water on our water resources must be monitored and addressed.

While most states require drillers to dispose of fracking waste water in deep wells below impermeable rock layers, Pennsylvania that has no deep wells has allowed drillers to discharge their fracking waste water through sewage treatment plants into rivers. Sewage treatment plants are designed to separate solids and use bacteria to treat biological waste. They are not equipped to remove or neutralize the contaminants in used hydro fracking fluid. In 2009 and 2010, public sewage treatment plants in Pennsylvania directly upstream from drinking-water intake facilities accepted wastewater that contained radionuclides at levels hundred even thousands of times the drinking-water standard despite the fact that these plants (and most sewage plants) were exempt from monitoring for radiation. Local regulators and gas producers believed the waste was not a threat because it would be diluted by treatment in the sewage treatment plants or the river itself, without sampling. They guessed at the environmental impact.

Finally, care must be taken to avoid degradation of watersheds and streams from the industry itself as large quantities of heavy equipment and supplies are moved on rural roads and placed on concrete pads. The watersheds must be monitored. And recent incidents and reports of potential contamination of drinking water supplies from fracking, the waste water from the fracking process underscore the dangers.The New York Times brought to light a 1987 E.P.A. report to congress titled “Management of Wastes from the Exploration, Development and Production of Crude Oil, Natural Gas and Geothermal Energy.” Corroborating documentation was obtained from state archives or from the EPA’s library by the New York Times.It appears that though seemingly forgotten, EPA had been aware of at least one well documented case of drinking water well contamination from fracking for 25 years. In addition, there are reports from several states noting contamination of drinking water wells in association with fracking, though no definitive proof because of lack of adequate testing and difficulties in understanding groundwater, the full extent to which hydro fracking fluids have contaminated or might in the future contaminate groundwater is unknown. However, many cases of associated contamination have been confirmed.

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