BUTTE — Atlantic Richfield says the company has begun construction on a water treatment plant for the Berkeley Pit in Butte.
The plan calls for the acidic, metal laden water filling the former open pit copper mine to be treated in four steps and discharged into Silver Bow Creek as early as January.
The Montana Standard reports Atlantic Richfield and Montana Resources plan a five-year test to ensure the treatment plan works.
Mark Thompson with Montana Resources says the treatment plan calls for water to be sent through an existing copper precipitation plant, which separates copper from the water.
The water would then go through an existing water treatment plant, be treated with lime in a tailings impoundment and pumped into the new “polishing plant,” which uses sand to filter out any suspended solids and neutralizes the water’s pH.