Jump to main content.


  Mine Waste Technology Program Activity III, Project 42 Physical Solutions for Acid Rock Drainage at Remote Sites: Demonstration Project (EPA/600/R-09/160) September 2008

This report summarizes the results of Mine Waste Technology Program, Activity III, Project 42, Physical Solutions for Acid Rock Drainage at Remote Sites, funded by the U.S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U.S. Department of Energy.

Acid rock drainage (ARD) is a serious environmental problem facing many inactive and active mine sites throughout the United States. The ARD from the Susie Mine in Rimini, Montana has a high ratio of iron to other metals, which means that conventional treatment technologies have limited applicability. MSE Technology Applications, Inc.’s Reductive Precipitation Process, a two-stage iron precipitation/filtration process with a polishing step to remove arsenic, is designed to treat high-iron ARD. Following successful laboratory treatability tests, the process was implemented at the Susie Mine, with an emphasis on zinc and arsenic removal. While zinc was effectively removed and the level of arsenic substantially reduced, the field system was never able to achieve arsenic levels below 10 micrograms per liter (µg/L). The lowest arsenic level measured in the treated effluent was 51.9 µg/L on October 3, 2006. Reasons for less-than-ideal arsenic removal include: numerous process upsets, a shortened schedule with minimal process optimization, and elimination of the polishing step. The process had mixed results, but was generally effective for the removal of cadmium, copper, lead, iron, and manganese. The primary recommendation from the field study was to continue to operate and maintain the Reductive Precipitation Process. Further process optimization and implementation of a polishing step for arsenic removal were also recommended.


Diana Bless

You will need Adobe Reader to view some of the files on this page.
See EPA's PDF page to learn more.

Office of Research & Development | National Risk Management Research Laboratory

Local Navigation

Jump to main content.