U.S. ethanol producers take great care to ensure that natural resources are used in a responsible and sustainable manner. The ethanol industry understands that meeting increased demand for renewable alternatives to petroleum-based fuels cannot come at the expense of ecological health and environmental quality.

Recently, the land and water impacts of increased ethanol production have come under intense scrutiny. However, when placed in proper context, the facts demonstrate that expansion of the ethanol industry has not had significant impacts on land and water resources. Further, today’s ethanol industry is more efficient than ever before in its use of water and other natural resources. And remarkable increases in agricultural productivity are allowing farmers to produce more feedstock per unit of land than at any time in the past.

As they have done for decades, ethanol producers will continue to seek improvements in production efficiency and embrace technologies and practices that lessen the environmental impacts of production.

THE AMOUNT OF WATER REQUIRED TO PRODUCE ETHANOL CONTINUES TO DECLINE

• Like most manufacturing processes, the production of ethanol requires water for processing and utility systems. A survey by the Renewable Fuels Association found that water usage by ethanol plants in 2006 averaged 3.45 gallons per gallon of ethanol produced. This is significantly less than in years past. As recently as 1994, more than six gallons of water were required to produce one gallon of ethanol. Indeed, a 2007 National Academy of Sciences report noted, “consumptive use of water is declining as ethanol producers increasingly incorporate water recycling and develop new methods of converting feedstocks to fuels that increase energy yields while reducing water use.”
• Further reductions in water use are expected in the near term, as new technologies promise to more efficiently use and recycle the water required for cooling towers, boilers and other processing components. Engineering and design firms estimate the average water use per gallon of ethanol produced is likely to continue to drop substantially in the next several years. One such firm estimates water requirements will soon be reduced “…to less than 1.5 gallons per gallon of ethanol produced.”

IN AGGREGATE, THE U.S. ETHANOL INDUSTRY IS A MINOR USER OF INDUSTRIAL WATER

• According to the U.S. Geological Survey, approximately 408 billion gallons of water are used per day for all purposes in the United States. Industrial water use is estimated at 18.5 billion gallons per day. Based on expected ethanol production of 9 billion gallons in 2008, the industry’s total water use is estimated at 85 million gallons per day. This equates to less than 0.5% of daily industrial water use and about 0.02% of total U.S. water use.
• To put the ethanol industry’s water requirement into proper perspective, consider that daily public water usage by the city of Chicago alone is five times greater than the entire U.S. ethanol industry’s water requirement.
• A typical 50 million gallon per year ethanol plant uses about 400,000 gallons of water per day. This is roughly equivalent to the daily water use of an 18-hole golf course. Water usage at the Sherman Hills Golf Course in Florida, for instance, averaged 363,000 gallons per day over a 12-month period, according to the St. Petersburg Times.
• As is the case with other industries, water withdrawal and discharge at ethanol plants is tightly regulated by state and federal agencies. Ethanol producers must secure local and state permits before during the biorefinery development process. If a proposed ethanol biorefinery were to threaten a particular area’s water supply, the project would not receive the necessary water permits.

PRODUCTION OF PETROLEUM-BASED FUELS REQUIRES SUBSTANTIAL WATER RESOURCES

• When evaluating the costs and benefits of a particular fuel source, it is important make appropriate comparisons to other competing fuels and forms of energy. Though the estimates vary widely, production of gasoline and other petroleum-based fuels requires a significant amount of water.
• According to the National Renewable Energy Laboratory (NREL), “Water use ranges between 65 and 90 gallons per barrel of crude oil processed and wastewater discharge ranges between 20 and 40 gallons, leaving 45 to 50 gallons of water consumed per barrel, or 2 to 2.5 gallons of water per gallon of gasoline.” Thus, using NREL’s conservative estimate, the current per-gallon water requirement for gasoline is similar to that of ethanol. But the aggregate quantity of water required to produce the gasoline consumed in the United States is nearly 1 billion gallons per day.
• It is also important to note that as ethanol’s water use requirement continues to decrease, the water use associated with oil production and refining is expected to increase. This is because nonconventional sources of oil, such as oil shale and tar sands, will increasingly be used to meet increases in oil demand. According to the U.S. Department of Energy, up to three barrels of water are required to produce one barrel of oil from oil shale, meaning more than 6 gallons of water are required to produce one gallon of gasoline from oil shale.

WATER REQUIREMENTS FOR ETHANOL FEEDSTOCKS ARE OFTEN MISUNDERSTOOD

• Critics of the ethanol industry often suggest that biofuels feedstock production consumes massive amounts of water. It is true that corn requires large amounts of water to grow; a bushel of corn needs approximately 4,000 gallons of water in a growing season. But what often goes unreported is that nearly nine out of every 10 corn acres in the United States are rain-fed and require no irrigation other than natural rainfall. Further, because most ethanol production occurs in the central Corn Belt where corn is primarily rain-fed, NREL says “As much as 96 percent of the field corn used for ethanol production is not irrigated at all.”
• Additionally, much of the water taken into a corn plant is released back into the air through transpiration. In fact, one acre of corn gives off about 4,000 gallons of water per day through evapo-transpiration, according to the U.S. Geological Survey (USGS).
• Future biofuels feedstocks may have even less of an impact on water resources. Field trials for cellulosic energy crops like switchgrass and miscanthus suggest such crops may need less water than corn if groundwater irrigation is necessary. Further, cellulosic feedstocks like agricultural residues, municipal waste, and forestry waste have no direct water use requirement at all.

U.S. ETHANOL PRODUCTION HAS NOT BEEN A MAJOR DRIVER OF AGRICULTURAL LAND USE

• Recently, the potential land use implications of increased demand for biofuels in the United States have been at the center of an intense public discourse. Using oversimplified logic and questionable assumptions, critics have suggested future growth in U.S. demand for biofuels like ethanol would cause significant direct and indirect conversion of land in the United States and abroad. However, land use change isn’t nearly that simple. Experts at the U.S. Department of Energy’s Oak Ridge National Laboratory say global land use change has been “largely independent of crop markets.” Rather, they say, land use changes are “driven by interactions among cultural, technological, biophysical, political, economic, and demographic forces—not singular events.”
• Historical trends appear to indicate that increased U.S. ethanol demand has not been a significant driver of land use change. Increased crop productivity per unit of land has provided the growth in agricultural production necessary to meet heightened demand. It seems likely that small amounts of previously cultivated land enrolled in the Conservation Reserve Program may return to production, but more pronounced gains in productivity promise to mitigate the need for large amounts of new agricultural lands in the future.
• Though U.S. ethanol production is expected to increase substantially in the years ahead, the total amount of agricultural land needed to support the U.S. ethanol industry will continue to be immaterial in the context of global agricultural land use. Projections from Informa Economics, a leading agricultural consulting firm, suggest the land required to produce 15 billion gallons of grain ethanol in the United States in 2015 will amount to less than 1 percent of world cropland.

INCREASED CROP PRODUCTIVITY RELIEVES PRESSURE ON LAND RESOURCES

• Heightened demand for crops in the last several decades has been met primarily through increased productivity per unit of land. Higher crop yields relieve pressure on land resources and mitigate the need to expand agricultural land use. According to the United Nations Food and Agriculture Organization, yield increases are responsible for about 78 percent of global crop production growth between 1961 and 1999, with about 7 percent from more intense agriculture practices, and just 15 percent coming from agricultural area expansion. The role of higher yields in increased U.S. crop production is even more pronounced, as U.S. agricultural land use has actually decreased in the last several decades.
• Average corn yields have advanced rapidly in the United States. Improved management practices and seed technology advances are responsible for the dramatic increases in corn yields over the past four decades. During the decade of the 1970s, corn yields averaged 90.1 bushels per acre. The average yield in the 1980s was 106.7 bushels per acre, while the average yield in the 1990s was 123.8. From 2000 to 2007, yields have averaged 144.8 bushels per acre. As demonstrated by the reduction in deviations from the long-term trend, improved corn genetics have also helped mitigate yield shortages due to weather shocks.

FEED CO-PRODUCTS FROM ETHANOL PRODUCTION HELP MITIGATE IMPACTS ON LAND USE

• The feed coproducts generated by ethanol biorefineries play an important role in mitigating impacts on land use change. Each 56-pound bushel of corn that is processed by an ethanol biorefinery results in not only 2.8 gallon of renewable fuel, but also 17 pounds of residual feed grains (commonly referred to as distillers grains, corn gluten feed, and corn gluten meal). Approximately 23 million metric tons of livestock feed were produced in 2007/08, an amount of feed equivalent to nearly 1 billion bushels of corn.
• Ethanol production uses only the starch portion of the corn kernel, while the remaining protein, fat, and other nutrients, vitamins and minerals are passed through the process into the distillers grains. Accordingly, only 2/3 of every acre of grain “dedicated” to ethanol production is actually used for biofuel production. The remaining 1/3 of the acre is more accurately characterized as producing livestock feed.