Unpolluted

Clean, unpolluted water.
water, ground water found at and beneath the water table, in the zones of soil and bedrock, which are saturated.
water, hard water with a high content of dissolved mineral salts.

Changes in groundwater flow produced by mining operations often bring otherwise unpolluted waters into contact with certain mineral materials which are leached from the soil and produce an acid mine drainage.

See also: Acid, Water, Mining, Groundwater, Reduction