Lake #77 is a lake formed when a former coal mining pit was closed and filled with water. When this lake was formed, sulfites from the former mining area turned the water acidic, with a pH of around 2. There is also high concentrations of iron minerals in this lake, the oxidatio of which gives the sediment a variety of bright colors, including the orange-red you see in many of these photos. Normally, sampling this site requires a inflatable boat, but in the winter, our sampling locations are all accessible by waking (on the ice), although decidedly less pleasant.
