Abstract: Fisher Creek, a stream affected by acid mine drainage in the Beartooth Mountains of Montana, was studied to determine the extent to which copper (Cu) and zinc (Zn) would be removed from stream water when pH was increased by a pulse of sodium hydroxide (NaOH). Although the pH adjustment study indicated that precipitated Fe(OH) “SUB 3” (am) could rapidly remove Cu and Zn from a stream affected by acid mine drainage, the pH should be maintained in an optimal range (7 to 8.5) to maximize removal by adsorption. -from Authors

Abstract: Extreme acid-rock drainage is the dominant long-term environmental concern at the Summitville mine and could have been predicted given the geological characteristics of the deposit. Extensive remedial efforts are required to isolate both unweathered sulfides and soluble metal salts in the open-pit area and mine-waste piles from weathering and dissolution. Results of studies as of late 1993 indicate that mining at Summitville has had no discernible short-term adverse effects on barley or alfalfa crops irrigated with Alamosa River water. Remediation of the site will help to ensure that no adverse effects occur over the longer term. -from Editor