May 1, 2017
The Great Salt Lake’s water is full of salt and minerals—and a serious dose of mercury. Most of that toxic metal was deposited naturally by the atmosphere, but thanks to bacteria and an engineering project, most of it ended up concentrated at the bottom of the lake in the form of particularly nasty methylmercury. But five years after the methylmercury was first documented, it appears to be gone, without any warning or cleanup efforts. Now scientists want to know where it all went.