A geologist with EA Engineering, Science, and Technology, Inc. reviews a core sample from a sonic drilling rig during a remedial investigation into the presence of Per- and Polyfluoroalkyl substances at Truax Field in Madison, Wisconsin, Dec. 12, 2023. The investigation marks the second major step in the Environmental Protection Agency’s Comprehensive Environmental Response, Compensation, and Liability Act process which will guide the mitigation of PFAS compounds on and around the Air National Guard installation. (U.S. Air National Guard photo by Senior Master Sgt. Paul Gorman)