Stephanie Pappas of LiveScience writes:
"To get potash out of the ground, miners pump water from the nearby Colorado River through wells into an underground mine, according to mining company Intrepid. The water dissolves the potash salts buried 3,000 feet (914 meters) below the surface. The now-briny water is pumped back up into the shallow ponds seen here, where the sun evaporates off the water, leaving salt crystals behind.
The ponds get their bright blue color from a dye, much like food coloring, added to the water. The color helps the ponds absorb more light, speeding up the evaporation process."
via neatorama.com
