The Water Footprint of Shale Gas Development by Coryn S. Wolk, September 6, 2012, Protecting our Waters
Recent studies examining potable water supplies on a global scale, the current trends in American water consumption, and the causes of depletion of this essential resource are helping us to understand that the footprint of shale gas development expands indefinitely when measured in water. Considering that only 1% of the earth’s water is drinkable, how we manage water will define our future and the future of the planet. Since 99% of that water is groundwater[1], how we look after our aquifers is the most critical component involved. Examining the demand for water worldwide, a report published in August in Nature concludes that we are overexploiting our aquifers…. Of the seven nations where the groundwater footprint is greatest, the U.S. is one of the fastest speeding towards disaster.
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Enter hydraulic fracturing (“fracking”) for shale gas. The water footprint for shale gas is defined in two main ways – water consumed and water polluted. Water Consumed: Fracking is a water intensive process requiring an average 5 million gallons of water per well and up to 9 million gallons for some of the longest well bores. Between 8-10% of the volume injected in Pennsylvania’s Marcellus Shale wells returns to the surface as flowback. That means up to 90% of the fresh water injected in the fracking process is sequestered in deep geologic formations. This depletion is fundamentally different than evaporative losses for agriculture, electricity generation, and recreational uses like golf courses, which essentially recycle the water used into the atmosphere where it returns as precipitation. Water injected for fracking is locked away from the earth’s natural hydrologic cycle, a total loss that doesn’t return to its source.
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Water Polluted: The other way fresh water is depleted is through pollution. Frack water is deliberately polluted by the addition of frack chemicals and inadvertently but inescapably contaminated by contact with naturally occurring highly toxic pollutants where the shale gas is contained. Chemical additives make up to 2% of the frack fluid injected in gas extraction.[7] Up to 750 chemicals have been used across the nation in frack fluids[8]; in Pennsylvania and West Virginia 322 unique chemicals and at least another 21 additional compounds whose ingredients are kept secret by drillers have been documented in frack fluids used in the Marcellus Shale.[9] Many of these chemical additives are toxic and are known carcinogens and endocrine disruptors; long term exposure can cause nervous system, respiratory and organ damage. Some, such as benzene, are so dangerous that even miniscule amounts can cause disease.[10] But even if only benign additives were used for fracking, the water that returns to the surface is highly toxic, polluted with materials found in the shale formations[11]. Many of these materials, including sodium, chloride, bromide, arsenic, barium, and naturally occurring radioactive materials (NORM)[12] are found at levels that exceed safe drinking water standards.
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A recent report by the U.S. General Accountability Office concludes that the water produced by shale fracking poses health risks to humans and the environment.[17] A Risk Analysis released in August of this year concluded that five main contamination pathways for frack fluids exist and even in a best-case scenario, an individual well would potentially release at least 200 cubic meters of contaminated[18] fluids (cubic meter= ~264.17 fluid gallons).[19] Multiplied by the 100,000 new shale gas wells that the U.S. Dept. of Energy says can be expected nationally and it is quickly evident that lots of water will be contaminated by fracking, depleting clean water resources – at least 5 billion gallons using these estimates.
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And findings by hydrogeologists Paul Rubin[22], Tom Myers[23] and Cornell Professor Tony Ingraffea have verified that gas wells can and do leak, some immediately, some in a few years’ time. Paul Rubin makes it clear that eventually all gas wells being constructed today will leak methane and/or polluted fluids into aquifers, assuring the loss and degradation of irreplaceable water in untold volumes.[24] That’s unending loss, a suffocating footprint that cannot be undone and that deprives generations to come. [Emphasis added]
The Water Footprint of Shale Gas Development
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