æktˈɪvᵻɾi sˈɪmɪlɚ tʊ ˈæsɪd mˈaɪn dɹˈeɪnɪdʒ, bˌʌt ˌɔn ɐ mˈʌtʃ lˈoʊɚ skˈeɪl, ɪz ˈɔːlsoʊ fˈaʊnd ɪn nˈætʃɚɹəl kəndˈɪʃənz sˈʌtʃ ɐz ðə ɹˈɑːki bˈɛdz ʌv ɡlˈeɪʃɚz, ɪn sˈɔɪl ænd tˈæləs, ænd ɪnðə dˈiːp sˈʌbsɚfˌɪs.
Activity similar to acid mine drainage, but on a much lower scale, is also found in natural conditions such as the rocky beds of glaciers, in soil and talus, and in the deep subsurface.