Dr. Mark Engle is a geochemist and hydrogeologist who has led applied research broadly focused on environmental aspects of energy use, production, and utilization with particular emphasis on linkages to water resources and air quality for more than 25 years. In his role as a consultant with GSI, he provides expertise on mathematical and geochemical methods to source compounds in the environment, evaluates and assesses analytical and laboratory methods, and creates study designs to identify key processes for complex problems. Dr. Engle is a Professor in the Department of Earth, Environmental and Resources Sciences at the University of Texas at El Paso and is Editor-in-Chief of Applied Computing and Geosciences.