Department of
Environmental Quality

Southeast Idaho Phosphate Mining

Southeast Idaho is a major phosphate-producing region, and phosphate mining has been an important industry in the area since the early 20th century. The process of mining phosphate ore from the earth generated open pits and piles of overburden materials covering the phosphate ore. The overburden material is naturally elevated in selenium and other trace metals. When exposed to the elements, these overburden piles can release selenium and other trace metals to the environment.

The map below depicts mine sites within the southeast Idaho phosphate mining region.