Affiliation: | The authors are Co-directors of the National Center for Ground Water Research. C. H. Ward is Professor and Chairman, Department of Environmental Science and Engineering, Rice University, Houston, Texas 77251;N. N. Durham is Dean, Graduate College, Oklahoma State University, Stillwater, Oklahoma 74078;and L. W. Canter is Professor of Civil Engineering and Environmental Science, University of Oklahoma, Norman, Oklahoma 73019. |