Uranium? Yes, really: it comes out of granite rocks up deep water wells in the Georgia Piedmont. The other metals arsenic come from human energy, industrial, and agricultural activities, ranging from fenceposts to Plant Scherer, dirtiest coal plant in the country, emitting mercury, some of which ends up in the Alapaha River. Here’s video of Janet McMahan speaking about this:

Janet McMahan spoke to the group after the
Adopt-A-Stream water quality testing training
taught by Angela Bray and Richard Batten.
Video by Gretchen Quarterman for WWALS Watershed Coalition (WWALS),
Valdosta, Lowndes County, Georgia, 5 August 2012

Janet McMahan adds: