One of our collaborators made news this week for his pilot study quantifying marijuana use in Seattle and Tacoma. Dan Burgard, a chemist at the University of Puget Sound, is analyzing wastewater from sewage treatment plants to identify levels of metabolized THC. The study is designed to determine if new recreational marijuana laws are leading to an increase in marijuana use. It will also look at trends over time, and how the legal trade of marijuana compares with the black market. Burgard is using analytical equipment at the Center for Urban Waters for his study.