Utah's land, air and water were besieged by a number of challenges in 2015, with state regulators tackling all manner of concerns, such as response to the 3-million gallon Gold King Mine spill and continued monitoring of a migrating groundwater plume on Salt Lake City's east bench. In its annual State of the Environment report, the Utah Department of Environmental Quality took a look back on the milestones accomplished over the past 12 months and the problems that are likely to persist.