Dr. Heppner has fifteen years of experience conducting hydrogeologic investigations in both applied and research settings.  His work has included aquifer test planning, performance, and analysis; basin safe yield and groundwater supply sufficiency assessments; groundwater flow and solute transport analytical and numerical modeling in support of hazardous waste site investigations and remedial action efficacy evaluations; watershed hydrologic response and sediment transport modeling; research into unsaturated flow and recharge processes in fractured rock; development and application of hydrologic models and data analysis tools; assessment of stream channel geomorphology; and collection of hydrologic field data in multiple environments.  Dr. Heppner has published articles in peer-reviewed journals related to recharge in fractured rock settings, watershed-scale hydrologic response simulation, and sediment transport modeling, and has presented at conferences on topics including basin sustainable yield estimation and salinity in shallow groundwater.