You are here:
MINE WASTE TECHNOLOGY PROGRAM - UNDERGROUND MINE SOURCE CONTROL DEMONSTRATION PROJECT
Citation:
MCCLOSKEY, L. MINE WASTE TECHNOLOGY PROGRAM - UNDERGROUND MINE SOURCE CONTROL DEMONSTRATION PROJECT. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-05/071 (NTIS PB 2005 110810), 2005.
Impact/Purpose:
to inform the public.
Description:
This report presents results of the Mine Waste Technology Program Activity III, Project 8, Underground Mine Source Control Demonstration Project implemented and funded by the U. S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U. S. Department of Energy (DOE). Project 8 addresses EPA's technical issue of Mobile Toxic Constituents - Water - through a field demonstration at a remote, inactive underground mine.
This project was undertaken to demonstrate the feasibility of injecting a water-activated, expansive, flexible, and closed-celled source control material (grout) into a rock fracture system to reduce or eliminate the flow of acid mine drainage (AMD) into the underground workings of an abandoned mine. The Miller Mine, located in the Big Belt Mountains of Broadwater County, Montana, was selected for the field demonstration.
Grout injection was completed in two phases to reduce or eliminate AMD generated when groundwater contacts sulfide mineralization associated with the Miller Mine Reverse Fault and associated fractures. Phase I included drilling, coring, and grouting 10 approximately 624-feet drill holes in Precambrian sedimentary and Tertiary igneous rocks using core and Jackleg drilling methods. Results of Phase I work indicate that fracture flow was significantly reduced by approximately 77 +/- 5%, and the metals loading (particularly for arsenic, cadmium, copper, nickel, aluminum, and lead) was reduced by at least 80%.
Phase II grout injection included using Jackleg drilling and downstage grouting methods (approximately 400 feet) completed to seal rock fractures with observed flow that intercepted underground workings. Phase II work further reduced metals loading (zinc, iron, and copper) into the underground workings.
While the dissolved metal concentrations at the portal were not reduced, the mass loading of the major metals (iron, zinc, and aluminum) were reduced by an order of magnitude. This is the direct result of grout injection into the fracture system. The grouting reduced fracture flow and the metals load resulting from the diversion of fracture flow away from mineralized areas and encapsulation of the sulfide mineralization.