Photo Gallery - Sulfate Reducing Bioreactor Tratability Study Pilot Project

2008 photos by Tim Buxton

Two barrel-sized “bioreactors” were constructed as a treatability study pilot project on the Ore Hill site to evaluate whether this approach can successfully treat the acid mine water containing hazardous metals remaining on the site after the 2006 work.   

Water is piped from the pit area to two drums (“bioreactors”) inside the treatment shed.  The bioreactors contain wood chips, limestone, hay, and manure in different proportions.  Natural bacteria living on the material in the bioreactors remove the hazardous metals, and the limestone increases the pH of the water.   This type of water treatment is “passive,” in that it doesn’t require other chemicals to be added, or electricity, and it requires little maintenance, so it is cost effective.

Water line installed in insulating straw bales from pit in center of former mine tailings area to approximately 150’ downstream.  This provides gravity flow of water to be treated in treatment shed. (Click on image for larger photo)

Assembling the treatment shed within the former tailings area. (Click on image for larger photo)

Mixing pilot project treatment cell materials:  straw, wood chips, limestone, and manure. (Clck on image for larger photo)

Placing mixed treatment cell material in drums. (Click on image for larger photo)

Plumbing water to treatment drums.  Mine-impacted water is gravity-fed to top of gutters, which are lined with limestone, passes through limestone and is routed to one of two drums, or to overflow.  Note insulation and 2x4 reinforcement: pilot project is planned to run through the winter, so shed and water supply line were insulated to attempt to maintain flow, and shed was reinforced to withstand snow load. (Click on image for larger photo)

Completed pilot project shed as of August 8, 2008.  If this pilot project is successful and a full-sized system is installed, it should reduce the metals leaving the mine site to near background levels, helping to restore the ecology of the stream and meet water quality goals.  Note:  the shed was vandalized in mid-September, but we hope we can continue the project to determine whether this passive treatment process can be successful in at Ore Hill. (Click on image for larger photo)