61. Numerical simulation of the alluvium and terrace aquifer along the north Canadian River from Canton Lake to Lake Overholser, central Oklahoma Author/Creator: Christenson, Scott C., author Publication/Creation: Oklahoma City, Oklahoma : U.S. Geological Survey, 1983 Resource Type: Book Access & Availability: Loading
62. Nonpoint-source agricultural chemicals in ground water in Nebraska : preliminary results for six areas of the High Plains aquifer Author/Creator: Chen, Hsiu-Hsiung, 1937- author Publication/Creation: Lincoln, Nebraska : U.S. Geological Survey, 1987 Resource Type: Book Access & Availability: Loading
63. Nitrate concentrations in ground water in the paleovalley alluvial aquifers of the Nemaha Natural Resources District, Nebraska, 1989 and 1994-96 Author/Creator: Chen, Abraham H., author Publication/Creation: Lincoln, Nebraska : U.S. Geological Survey, 1998 Resource Type: Book Access & Availability: Loading
64. National Water-Quality Assessment of the Lake Erie-Lake St. Clair Basin, Michigan, Indiana, Ohio, Pennsylvania, and New York : environmental and hydrologic setting Author/Creator: Casey, George D., author Publication/Creation: Columbus, Ohio : U.S. Department of the Interior, U.S. Geological Survey, 1998 Resource Type: Book Access & Availability: Loading
65. Nitrate and pesticides in ground water of the eastern San Joaquin Valley, California : occurrence and trends Author/Creator: Burow, Karen R., author Publication/Creation: Sacramento, California : U.S. Geological Survey, 1998 Resource Type: Book Access & Availability: Loading
66. A new cation-exchange method for accurate field speciation of hexavalent chromium Author/Creator: Ball, J. W. Publication/Creation: Boulder, Colo. : U.S. Dept. of the Interior, U.S. Geological Survey, 2003 Resource Type: Book Access & Availability: Loading
67. Nitrate in the Columbia aquifer, central Delmarva Peninsula, Maryland Author/Creator: Bachman, L. Joseph, author Publication/Creation: Towson, Maryland : U.S. Geological Survey, 1984 Resource Type: Book Access & Availability: Loading
68. Nitrate and selected pesticides in ground water of the Mid-Atlantic region Author/Creator: Ator, Scott W., author Publication/Creation: Baltimore, Maryland : United States Geological Survey, 1997 Resource Type: Book Access & Availability: Loading
69. Nitrate in ground water and spring water near four dairy farms in North Florida, 1990-93 Author/Creator: Andrews, William J., 1962- author Publication/Creation: Tallahassee, Florida : U.S. Geological Survey, 1994 Resource Type: Book Access & Availability: Loading
70. Nutrients and pesticides in ground water of the Ozark Plateaus in Arkansas, Kansas, Missouri, and Oklahoma Author/Creator: Adamski, James C., author Publication/Creation: Little Rock, Arkansas : U.S. Geological Survey, 1997 Resource Type: Book Access & Availability: Loading