Fisher Creek, a stream affected by acid mine drainage in the Beartooth
Mountains of Montana, was studied to determine the extent to which co
pper and zinc would be removed from stream water when pH was increased
by a pulse of sodium hydroxide. As stream pH increased, copper and zi
nc were rapidly and completely removed from stream water by adsorption
or coprecipitation with freshly precipitated hydrous ferric oxide. In
practice, the best way of increasing the pH of streams impacted by ac
id mine drainage would be to increase the alkalinity of tributaries by
lining their channels with limestone rock.