Water Implications of Biofuels Production in the United States (2008)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Committee on Water Implications of Biofuels Production in the United States Water Science and Technology Board Division on Earth and Life Studies 

THE NATIONAL ACADEMIES PRESS  500 Fifth Street, N.W.  Washington, DC 20001 NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the coun- cils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the panel responsible for the report were chosen for their special competences and with regard for appropriate balance. Support for this study was provided by the McKnight Foundation under Grant No. 06-1201, Energy Foundation under Grant No. G-0611-08651, National Science Foundation under Grant No. CBET-0716901, U.S. Environmental Protection Agency under Order No. EP07C000287, and the National Research Council Day Fund. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organiza- tions or agencies that provided support for the project. International Standard Book Number-13:  978-0-309-11361-8 International Standard Book Number-10:  0-309-11361-X Cover: Switchback photo courtesy of the U.S. Department of Agriculture. Additional copies of this report are available from the National Academies Press, 500 Fifth Street, N.W., Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet, http://www.nap.edu. Copyright 2008 by the National Academy of Sciences. All rights reserved. Printed in the United States of America 

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Acad- emy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding en- gineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Charles M. Vest is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Insti- tute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Harvey V. Fineberg is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sci- ences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the gov- ernment, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Ralph J. Cicerone and Dr. Charles M. Vest are chair and vice chair, respectively, of the National Research Council. www.national-academies.org 



COMMITTEE ON WATER IMPLICATIONS OF BIOFUELS PRODUCTION IN THE UNITED STATES JERALD L. SCHNOOR, Chair, University of Iowa, Iowa City OTTO C. DOERING III, Purdue University, West Lafayette, Indiana DARA ENTEKHABI, Massachusetts Institute of Technology, Cambridge EDWARD A. HILER, Texas A&M University, College Station THEODORE L. HULLAR, Cornell University, Ithaca, New York G. DAVID TILMAN, University of Minnesota, St. Paul NRC Staff WILLIAM S. LOGAN, Study Director NANCY HUDDLESTON, Senior Communications Officer MICHAEL J. STOEVER, Senior Program Assistant  



Acknowledgments T his report is the result of a process in which many people and organi- zations participated. The matter of biofuel development and implica- tions to water resources was raised as an emerging issue of significant concern by the Water Science and Technology Board (WSTB) in 2006. Members of the board (Appendix B), working with WSTB staff and prospec- tive sponsors, determined the approach to address this issue, crafted the task statement, identified candidates for the steering committee, and provided other general oversight. The steering committee (see listing in front matter and biographies in Appendix C) organized and hosted the colloquium and wrote this report. Fifteen individuals gave much time to prepare and make presentations and discussions (see colloquium agenda in Appendix A and biographical sketches in Appendix D) at the colloquium, thus providing a rich basis for deliberations at the colloquium itself by the 130 individuals present (too numerous to list) and by the steering committee following the event as it deliberated its way to consensus on the content of this report. This project was sponsored by the McKnight Foundation, Energy Foun- dation, National Science Foundation, National Research Council (NRC) Day Fund, and U.S. Environmental Protection Agency. This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with pro- cedures approved by the NRC’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of this report: Mary Jo Baedecker, U.S. Geological Survey (emeritus); Paul Bertsch, Savannah River Ecology Lab; Christopher Field, Carnegie Institution vii 

viii Acknowledgments of Washington; David Fischhoff, Monsanto Company; Leonard Shabman, Resources for the Future, Inc.; H. Eugene Stanley, Boston University; and David Zilberman, University of California, Berkeley. Although these reviewers provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommen- dations, nor did they see the final draft of the report before its release. The review of this report was overseen by George M. Hornberger, University of Virginia. Appointed by the NRC, he was responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution. 

Contents SUMMARY 1 1 ABOUT BIOMASS, BIOFUELS, AND WATER 9 Water and Biofuel Crops, 10 Water and Biorefineries, 13 Projected Future Growth of Ethanol Production, 14 References, 17 2 CROP WATER AVAILABILITY AND USE 19 Will There Be Enough Water to Grow Crops for the Projected Biofuels Demand?, 19 How Will Biomass Production Interact with the Overall Water Resource, 22 Will the Water Requirements of Biofuels Crops in the Future Be Different?, 23 How Might Climate Change Affect This Picture?, 24 References, 24 3 WATER QUALITY 27 How Might Increased Biomass Production Affect the Water Quality of Our Rivers?, 27 What May Be the Impacts of Biomass Production on the Nation’s Coastal and Offshore Waters?, 30 What are Some Likely Effects on Groundwater Quality?, 31 How Can Environmental Effects of Different Biomass Be Compared?, 33 References, 35 ix 

 Contents 4 AGRICULTURAL PRACTICES AND TECHNOLOGIES TO REDUCE WATER IMPACTS 37 What are the Available Practices and Technologies?, 37 How Can Biotechnology Contribute?, 41 References, 42 5 WATER ISSUES OF BIOFUEL PRODUCTION PLANTS 45 How Much Water Do Biorefineries Use?, 45 How Does Biorefinery Water Use Compare to the Amount Needed to Grow Its Feedstock?, 49 What Water Quality Issues are Associated with Biorefineries?, 51 References, 53 6 POLICY OPTIONS 55 What Factors Have Shaped the Current Policy Context?, 55 How Can Policy Reduce Impacts of Biofuel Production on Water Quality?, 57 What Metrics Can Be Used to Inform Policy Decisions?, 60 References, 61 APPENDIXES A AGENDA FOR THE COLLOQUIUM ON WATER IMPLICATIONS OF BIOFUELS PRODUCTION IN THE UNITED STATES 63 B WATER SCIENCE AND TECHNOLOGY BOARD 67 C  IOGRAPHICAL SKETCHES FOR COMMITTEE ON WATER B IMPLICATIONS OF BIOFUELS PRODUCTION IN THE UNITED STATES 69 D BIOGRAPHICAL SKETCHES FOR SPEAKERS AND DISCUSSANTS 73