Dr. Charles D. Shackelford
Charles D. Shackelford is Professor and Head of the Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, Colorado, USA. He has 30 years of experience pertaining to the geoenvironmental aspects of waste management and environmental remediation, is a registered professional Civil Engineer in California and Colorado, and has served as an expert on waste disposal issues on numerous occasions for private companies and federal agencies. Dr. Shackelford's research is focused primarily on evaluating flow and transport of hazardous liquids and contaminants through soil and geosynthetic containment barriers, such as compacted clay liners (CCLs) and geosynthetic clay liners (CCLs), commonly used in geoenvironmental containment applications (e.g., landfills, surface impoundments, lagoons, secondary containment of above-grade fuel storage tanks, etc.), as well as through soil-bentonite (SB) vertical cutoff walls used for in situ control and containment of polluted groundwater. His most significant contributions have related to characterizing diffusion of potential contaminants through these barrier materials. Examples of recently completed research include (i) evaluating the significance of clay membrane behavior (solute restriction, chemico-osmosis) on contaminant transport through clay barriers, (ii) determining the long-term (2-3 year) hydraulic performance of GCLs exposed to hazardous chemical solutions, (iii) modeling the hydrologic water balance for alternative covers at waste disposal sites, (iv) modeling the use of sulfate reducing bacteria in permeable reactive treatment trenches for precipitation of metals in acid mine drainage, and (v) characterizing the mobility and fate of organic compounds existing as mixtures in groundwater. Examples of his current research efforts include (i) evaluating the use of a bentonite polymer nanocomposite (BPN) as a more resilient substitute for traditional bentonites in bentonite based containment barriers, (ii) evaluating the effect of an enhanced attenuation capacity via zeolite amendment to SB backfills on the long-term performance of vertical cutoff walls, (iii) determining the extent and magnitude of semipermeable membrane behavior in unsaturated clay, (iv) measuring solute transport properties of highly compressible and contaminated geomaterials (e.g., mine tailings, contaminated dredged sediments, etc.), and (v) evaluating diffusion of radionuclides through containment barrier materials, such as concrete and compacted bentonites used as backfills and buffers for high level radioactive waste containment. The majority of his research has been funded by the National Science Foundation (NSF), the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE), and he received the NSF National Young Investigator Award in 1992. In 1995, his research contributions pertaining to the role of diffusion in containment barrier design were recognized with the receipt of the Walter L. Huber Civil Engineering Research Prize from the American Society of Civil Engineers (ASCE). Between 2001 and 2006, he served as the Director of the Rocky Mountain Regional Hazardous Substance Research Center (HSRC) for EPA Region 8, one of five EPA sponsored HSRCs during that period covering the 10 EPA designated geographical regions comprising the U. S. Dr. Shackelford has given 99 invited presentations in the U. S., Puerto Rico, and 15 other countries (Australia, Argentina, Brazil, Canada, Chile, China (Hong Kong), England, France, Germany, Italy, Japan, Scotland, Switzerland, United Arab Emirates, and Wales), including several state-of-the-art, keynote, and honorary lectures at international conferences. He has served as an Editor for both the ASCE Journal of Geotechnical and Geoenvironmental Engineering, and the Journal of Hazardous Materials published by Elsevier, Amsterdam, and currently serves as an Editorial Board Member of Geotextiles and Geomembranes, also published by Elsevier, and as an Associate Editor of the Canadian Geotechnical Journal published by the National Research Council, Ottawa, Ontario, Canada. He also was past chair of the Geoenvironmental Engineering Committee (GEC) of ASCE's Geo-Institute, and past co-chair for the Environmental Geotechnics Committee TC215 of the International Society of Soil Mechanics and Geotechnical Engineering (ISSMGE), and currently is still a member of both the GEC and TC 215. He also served as a member and the chair of ASCE Geo-Institute's Awards Committee, as a member of the Technical Coordination Council (TCC) of ASCE's Geo-Institute, and was an elected Board Member of the U. S. University Council on Geotechnical Education and Research (USUCGER). Dr. Shackelford was elected to the Academy of Civil Engineers at his alma mater, the Missouri University of Science and Technology, in April of 2005. Dr. Shackelford's career contributions to the field of Environmental Geotechnics were recognized through his receipt of the inaugural (2013) R. Kerry Rowe Honorary Lecture for Environmental Geotechnics by the ISSMGE. Professor Shackelford was elected as a Fellow of ASCE in 2015. His MS and PhD degrees are from the University of Texas at Austin in 1983 and 1988, respectively.