Dr. Johnston is a Supervisory Research Ecologist with EPA's Office of Research and Development in Athens, Georgia. His research is focused on water quality monitoring and modeling to forecast ecosystem services changes under management and climate change and their influence on human health and economic benefits. His interests include life cycle impact assessment, remote sensing, spatial modeling, and sustainability analysis. Current projects include forecasting lake cyanobacterial bloom probability and urban storm water management for enhanced aquifer recharge and safe, on-site non-potable use.