Lithotrophic microbes are responsible for the phenomenon known as acid mine drainage. Typically occurring in mining areas, this process concerns the active metabolism of pyrites and other reduced sulfur components to sulfate. One example is the acidophilic bacterial genus, A. ferrooxidans, that use iron(II) sulfide (FeS) to generate sulfuric acid. The acidic product of these specific lithotrophs has the potential to drain from the mining area via water run-off and enter the environment.
Acid mine drainage drastically alters the acidity (pH values of 2 - 3) and chemistry of groundwater and streams, and may endanger plant and animal populations downstream of mining areas. Activities similar to acid mine drainage, but on a much lower scale, are also found in natural conditions such as the rocky beds of glaciers, in soil and talus, on stone monuments and buildings and in the deep subsurface.