Our recent guest, Tom Aley (founder of Ozark Underground Lab), spent years refining and perfecting this dye tracing technique using coconut charcoal to understand how water flows through the Ozarks’ karst environment. Due to this expertise, today, Ozark Underground Laboratory conducts about 40% of all ground water tracing projects in the United States. You might think water only ever flows “downhill” and tracing water should be straightforward, but subsurface passages in karst create complexity