![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Electrochemical Tailings Cover
Primary Issue Addressed: Source Control
Secondary Issue Addressed: None
Project Site: MSE’s Mike Mansfield Advanced Technology Center in Butte, Montana
Collaborating Entities: MSE, Enpar Technologies, Inc., Placer Dome’s Golden Sunlight Mine
Cost Share: In-kind services provided by Golden Sunlight Mine.
Project Description
This project is being conducted at the MSE Technology Applications, Inc. (MSE) test facility in Butte, Montana. The purpose of the demonstration is to gather performance information for the electrochemical cover technology developed by Enpar Technologies, Inc., of Guelph, Ontario, Canada.
Fresh, nonoxidized tailings along with soil cover were transported from the Golden Sunlight Mine (GSM) near Whitehall, Montana. Lined, in-ground test cells, each equipped with a leachate collection system, along with a common sprinkler system, were constructed at MSE’s test facility. Two test cells, loaded with tailings and capped with soil cover, were constructed as identical control cells, receiving no electrochemical cover treatment. Two additional test cells, loaded with tailings and capped with soil cover, were constructed as identical test cells and were equipped with the electrochemical enhancement. Equal amounts of water will be applied to all four test cells following installation. Water application will continue through the summers of 2004 and 2005. Leachate will be pumped from each test cell to maintain an artificial water table and to provide water for analytical purposes. Leachate water quality will be monitored by regular sampling and analyses. Oxidation of the acid-generating tailings in all four cells will be assessed primarily by monitoring sulfate concentrations along with conductivity measurements. Sulfate mass produced by the two cells equipped with electrochemical cover treatment will be compared to that produced by the two control cells with no electrochemical cover treatment. It is anticipated that the two control cells will show higher sulfate concentrations and higher conductivity, resulting from tailings oxidation. The field installation will be monitored for 2 years, at which time, it will be dismantled and the tailings returned to GSM.
Status
Accomplishments in FY04 included resuming irrigation and successfully establishing the proper water table in the test cells in the spring of 2004, maintaining a system to pump and collect leachate, conducting multiple sampling events, and periodically checking the health of the electrochemical covers. Analytical results were inconclusive at the end of FY04; data from all four cells indicated that soluble salts were being flushed from the tailings with no noticeable indications of tailings oxidation.