Biophysical and Social Barriers Restrict Water Quality Improvements in the Mississippi River Basin

in the Mississippi River Basin Mark B. David,*,† Courtney G. Flint,‡ Gregory F. McIsaac,† Lowell E. Gentry,† Mallory K. Dolan,‡ and George F. Czapar †Department of Natural Resources and Environmental Sciences, University of Illinois , W503 Turner Hall, 1102 S. Goodwin Avenue, Urbana, Illinois 61801, United States ‡Department of Sociology, Social Work & Anthropology, Utah State University, 0730 Old Main Hill, Logan, Utah 84322-0730, United States Illinois State Water SurveyPrairie Research Institute, University of Illinois, 2204 Griffith Dr., Champaign, Illinois 61820-7495, United States