Geological Survey (U.S.) 246 Geological Survey (U.S.), 158 United States. Environmental Protection Agency. Office of Water 112 Colorado. Department of Public Health and Environment. Water Quality Control Division 100 Source Water Assessment and Protection Program (Colo.) 65 SpringerLink (Online service) 46 United States. Environmental Protection Agency 39 ScienceDirect (Online service) 24 California. State Water Resources Control Board 21 United States. Congress. House. Committee on Transportation and Infrastructure. Subcommittee on Water Resources and Environment 21 Colorado Water Resources Research Institute 19 National Water-Quality Assessment Program (U.S.) 19 Belitz, Kenneth 18 Colorado. Department of Agriculture 18 Library of Congress. Congressional Research Service, 18 United States. Congress. Senate. Committee on Environment and Public Works 16 Waskom, R. M. 16 Colorado State University. Cooperative Extension Service 15 U.S. Fish and Wildlife Service 14 United States. Bureau of Reclamation 14 California. State Water Resources Control Board, 13 Fram, Miranda S. 12 Ground Water Ambient Monitoring and Assessment Program (Calif.) 12 United States. Environmental Protection Agency. Office of Research and Development 12 Agricultural Chemicals and Groundwater Protection (Program) 11 Colorado. Water Quality Control Commission 11 United States. Environmental Protection Agency, 11 Belitz, Kenneth, 10 United States. Congress. House. Committee on Transportation and Infrastructure 10 Bauder, Troy Allen 8 Colorado. Agricultural Chemicals and Groundwater Protection Advisory Committee 8 National Risk Management Research Laboratory (U.S.) 8 United States. Natural Resources Conservation Service 8 Arizona. Department of Water Resources 7 Colorado State University. Environmental Resources Center 7 Colorado. Division of Plant Industry 7 Colorado. Oil and Gas Conservation Commission 7 Skogerboe, Gaylord V. 7 United States. Bureau of Indian Affairs 7 United States. Environmental Protection Agency. Assessment and Watershed Protection Division 7 United States. Environmental Protection Agency. Office of Ground Water and Drinking Water 7 United States. Environmental Protection Agency. Office of Science and Technology 7 United States. Environmental Protection Agency. Office of Wetlands, Oceans, and Watersheds 7 Colorado Foundation for Water Education 6 Colorado State University. Extension 6 Colorado Water Conservation Board 6 Colorado Water Institute 6 United States. Congress. Senate. Committee on Environment and Public Works, 6 United States. Congress. Senate. Committee on Environment and Public Works. Subcommittee on Water and Wildlife, 6 United States. Environmental Protection Agency. Office of Water, 6 United States. Environmental Protection Agency. Region VIII 6 United States. Forest Service 6 Ward, Robert C. 6 Breault, Robert F. 5 Copeland, Claudia, 5 Massachusetts. Department of Environmental Protection 5 Milby Dawson, Barbara J., 1964- 5 United States. Bureau of Land Management 5 United States. Congress. House. Committee on Rules 5 United States. Congress. House. Committee on Transportation and Infrastructure. Subcommittee on Water Resources and Environment, 5 United States. Department of Energy 5 United States. Environmental Protection Agency. Enforcement and Compliance Assurance 5 United States. Environmental Protection Agency. Office of Wastewater Management 5 United States. National Park Service. Natural Resource Stewardship and Science, 5 University of Colorado Boulder. Natural Resources Law Center 5 Ahuja, Satinder, 1933- 4 Bennett, George L., 4 Colorado Water Resources and Power Development Authority 4 Colorado. Department of Public Health and Environment 4 Environmental Research Laboratory (Athens, Ga.) 4 Francy, Donna S. 4 Gatz, Laura, 4 Ground Water Ambient Monitoring and Assessment Program (Calif.), 4 Hamilton, Pixie A. 4 Kansas Water Office 4 Kulongoski, Justin 4 Littin, G. R. 4 New Jersey. Department of Environmental Protection 4 Peart, Dale B. 4 Rickert, David A., 1940- 4 Shelton, Jennifer L., 4 Smith, Kirk P. 4 United States. Army. Corps of Engineers 4 United States. Bureau of Land Management, 4 United States. Bureau of Reclamation. Upper Colorado Region 4 United States. Congress. Senate. Committee on Energy and Natural Resources 4 United States. Environmental Protection Agency. Great Lakes National Program Office 4 United States. National Park Service 4 United States. Office of Water Resources Research 4 Walker, Wynn R. 4 Wisconsin. Department of Natural Resources 4 Ashman, Mary S. 3 Burton, Carmen A. 3 Colorado Geological Survey 3 Colorado State University 3 Colorado. Department of Health. Water Quality Control Division 3 Colorado. Division of Local Government 3 Colorado. Division of Water Resources 3 Connecticut. Department of Environmental Protection 3 Florida. Department of Environmental Regulation 3