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5 Water Use, Water Pollution, and Biofuels
Pages 67-84

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From page 67...
... " The Energy Independence and Security Act of 2007, Schnoor noted, requires that 36 billion gallons of biofuels of various sorts be used in the United States by 2022. According to Schnoor, to many it seems that there is a greater chance of a camel passing through the eye of a needle than of that mandate for cellulosic biofuels being met by 2022.
From page 68...
... "When you multiply that by hundreds of plants, it starts to make a significant number of jobs." Concerning the economics of ethanol production, he noted that the tax credit for blenders of corn ethanol expired in 2012, but biodiesel and cellulosic ethanol still enjoy a substantial tax credit of $1.01 per gallon. In 2012 growers planted a record 94 million acres of corn in the United States, and 40 percent of that was used in ethanol production --
From page 69...
... The trend t over thee past severall decades hass certainly beeen towardd growing mo ore and more bushels of ccorn per acre, as can be seeen in Figuure 5-1, whicch shows an average a increease of two bbushels per accre each year. y But histo ory also showws, he said, thhat the yield iis vulnerable to us outside forrces.
From page 70...
... . a groundwater supply that might be being depleted, there are real sustainability issues involved with the irrigation of that crop." There is relatively little irrigation needed in Iowa, where there is generally plenty of rain during the growing season, Schnoor said, but farmers growing corn in other parts of the country -- particularly the western half -- do irrigate.
From page 71...
... Thus, as the amount of of botth fertilizer an cropland devoted to o growing coorn has increaased, there haas been greatter and grreater negatiive impact on o water quaality even thhough the tottal acreag ge of land in the United States comm mitted to agricculture has nnot increassed in recentt decades. Annd it is not onnly the statess where corn is being grown for ethanol whose water qualityy is being afffected, he saiid, becausse the runofff from the croplands ennds up traveeling down tthe Mississsippi River all a the way to the Gulf of MMexico.
From page 72...
... So, it is a pretty intensive industry in terms of water." Given the effects of conventional biofuels production on water quality and quantity, the hope is that cellulosic biofuels would require less water, Schnoor said. Because there are not yet any commercial facilities in operation for producing cellulosic biofuels, it is impossible to be sure what the effects will be, but the expectation is that there will be some real benefits in terms of water quality and, to some extent, water quantity.
From page 73...
... One possible alternative to processing corn stover would be to use thermochemical processes with switchgrass and mixed prairie grasses. It has been suggested that this could produce cellulosic biofuels at higher yields with lower water inputs, less fertilizer use, and lower energy inputs than producing ethanol from corn -- and with lower greenhouse gas emissions as well -- but there is as yet little experience with this process (Tilman et al., 2006)
From page 74...
... "Iowa alone is making about 3.7 billion gallons per year." However, considerable water is required for this fuel, both in the growing of the corn and the processing of the corn into ethanol, and there are already local water problems -- drawdown of the aquifers -- associated with ethanol production facilities. There are also water quality issues, including the 8 grams of nutrients for every gallon of ethanol that ends up in the Gulf of Mexico and the 20 to 40 pounds of soil that are eroded for every gallon of ethanol produced.
From page 75...
... Thus, it takes a lot of fertilizer to replace that nitrogen. "Theoretically, the crop should take it all up," he said, "but if it rains after you apply, down the Mississippi it goes." Dennis Devlin of ExxonMobil then asked Schnoor whether, given the significant water use and the drawdown of the aquifers, local water districts are getting involved in the permitting process, and whether there have been any cases where water permit applications have been denied.
From page 76...
... "It drains off into local waters and streams where it does what fertilizer does -- it makes stuff grow." And although that may be desirable in farm fields, she said, in lakes, streams, and rivers it causes algae and other kinds of plants to "grow excessively and create all sorts of havoc," Kling said. According to an EPA survey of 43 percent of the lakes, reservoirs, and ponds in the United States, 67 percent of the surveyed bodies of water had impaired water quality to support their designated uses, and more than 12 million acres were impaired.
From page 77...
... When the algae die, they sink and decompose, using up all of the oxygen in the water column below the bloom. The result is that the oxygen concentration drops to 2 parts per million or so in large parts of the zone, and this is too little oxygen to support life.
From page 78...
... However, Klling pointed out, this com mes ost for the Gullf of Mexico, as all that raiin washes nut at a co utrients from tthe cornfieelds downstreeam. FIGUR RE 5-3 The sou urces of the Gu ulf of Mexico ddead zone.
From page 79...
... Researchers have examined the issue of how the use of switchgrass for biofuels might affect water quality, assuming that switchgrass could be made into an economically viable feedstock, Kling said. In particular, she described a study done in 2008 concerning various land uses in the Raccoon River Watershed in Iowa (Schilling et al., 2008)
From page 80...
... The decrease in nitrogen was much more modest -- only 11 percent with total conversion to switchgrass. TABLE 5-1 Water Quality Effects of Switchgrass Versus Corn Nitrogen Phosphorus Sediment Scenario Change Change Change Baseline 76% corn/soybean, -- -- -- 17% grassland, 4% forest, 2% retired cropland, 1% urban Corn 1.
From page 81...
... That depends, she said, on the question. "If the question is how we best use our land to produce the most valuable mix of food and fuel and environmental services, then we want to think broadly about water quality, greenhouse gases, the value of food, the value of energy, and everything else .
From page 82...
...  It is best not to identify the best specific approach, but instead to create clear market incentives to achieve outcomes. Discussion In the discussion session following Kling's presentation, an audience member began by asking Kling how she would go about putting a price on the various externalities in order to make sure that the market prices of the various biofuels options reflected their true costs.
From page 83...
... 2011. The potential for agricultural land use changes in the Raccoon River Basin to reduce flood risk: A policy brief for the Iowa Flood Center.


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