These potash ponds are found in Moab, a town in Utah, USA. The pools facilitate the evaporation process that produce potassium chloride (a.k.a. potash). Water in the ponds is dyed bright blue in order to help it absorb more sunlight and heat, reducing the time it takes the potash to crystallise.
Once crystallisation has occurred, the potash can be removed to be used as fertiliser. This process takes about 300 days and the ponds change colour as it goes through the different stages of evaporation