Sunday, November 17, 2013

Converting Corn To Ethanol: Accelerated Depletion of the Ogallala Aquifer

The Ogallala Aquifer provides irrigation water for much of the productive farmland in the Great Plains of the United States.  Most of Nebraska and parts of seven other states, including much of the Texas Panhandle and High Plains, are over the aquifer, and rely on it for irrigation.  The federal laws known as the Energy Policy Act of 2005 and the Energy Independence and Security Act of 2007 requires "renewable fuels" such as ethanol be blended into gasoline in ever-increasing amounts (http://www.epa.gov/OTAQ/fuels/renewablefuels/), and their passage led to the boom in production of ethanol as a renewable fuel to meet the mandates.

Almost 2 million people relied on the Ogallala Aquifer, which the USGS calls the High Plains aquifer system, for drinking water in 2000, according to the US Geological Survey poublication High Plains Regional Ground-Water Study (USGS, 2000) (http://co.water.usgs.gov/nawqa/hpgw/meetings/DENNEHY4.html and http://pubs.er.usgs.gov/publication/fs09100). With the increase in population in this area, the number is much higher today.

A result of the renewable fuels mandate is the increase of land being used to grow corn for ethanol production and soybeans for biodiesel.  Virgin land is being plowed and planted in corn as a result of the push for more ethanol.  Based on satellite imagery, a conservative estimate of 12. million acres has been lost to corn farming in Nebraska and the Dakotas since 2006, and the Conservation Reserve Program has lost hundreds of thousands of acres to corn crops. (http://bigstory.ap.org/article/secret-dirty-cost-obamas-green-power-push-1)

The more land that is converted to growing corn and the more corn that is converted to ethanol, the more water it takes.  It takes about 350,000 gallons of water over the 100-day season per acre of corn (http://www.colostate.edu/Depts/CoopExt/4DMG/Xeris/howmuch.htm). According to Jack Flobeck in http://gazette.com/the-water-and-corn-cost-for-a-gallon-of-ethanol/article/1506579, it takes 75 gallons of water to grow the corn needed to produce one gallon of ethanol. It then takes 3 gallons of water to produce a gallon of ethanol according to Mr. Flobeck (above link and according to the University of Illinois Extension Center, http://web.extension.illinois.edu/ethanol/wateruse.cfm). It is estimated that in 2007, ethanol production used 861 billion gallons of water (http://www.ecogeek.org/biofuels/2680).

There are ethanol plants over the aquifer with a production capacity of 2004.5 million gallons per year; production as of February 2013 of 1600.5 million gallons per year; and capacity under construction of 45 million gallons per year (http://www.neo.ne.gov/statshtml/122.htm). At 78 gallons water per gallon of ethanol produced, this means 124,839 million gallons of water were necessary to grow the corn and produce the ethanol from it.  In this region, a large percentage of the water necessary came from the aquifer.

About 95% of the water from the Ogallala Aquifer being used for agriculture and the area over the aquifer is about 65% of the total irrigated acreage in the United States. (http://www.hpwd.com/aquifers/ogallala-aquifer) The more acres that are put into growing corn and the more water-intensive industries built over the aquifer, the faster the water is pulled out of the aquifer.  We need a sensible policy for farming and industry in the area to preserve the water we have, not use it like there's no tomorrow; otherwise the day may come when there is no tomorrow for those of us who rely on the Ogallala Aquifer for our water, and those all over the world who rely on food produced in this region.

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