Montana Resources, ARCO plan Berkeley Pit treatment in 2019

Posted at 2:52 PM, Oct 01, 2018
and last updated 2018-10-01 16:52:40-04

BUTTE – There is a 2023 deadline to stop the rise of the toxic water in Butte’s Berkeley Pit. Montana Resources and the Atlantic Richfield Co. don’t want to wait that long.

“We’re ready to deal with it, so we’re going to start now to make sure we under we understand the system very thoroughly and we know we can do what needs to be done when that time comes,” said Mark Thompson of Montana Resources.

Atlantic Richfield’s Loren Burmeister added, “We’re going to be about four years ahead of schedule. 2023 was the date set under the consent decree for treating water from the mine site; we’re going to be treating and discharging water by 2019.”

Atlantic Richfield just started construction on a new polishing treatment plant off of Shields Avenue near the Berkeley Pit viewing stand. This facility will be the last phase in filtering out sediment from the treated pit water before it’s released into Silver Bow Creek.

Before that happens, Montana Resources will take the highly toxic pit water and treat it at its Horse Bend plant.

“It’s going to take a few circles through MR’s milling process first, but ultimately it will go to the pilot plant that’s being built and be discharged,” said Thompson.

This is being done to stop the polluted water in the pit from rising, which is currently only about 60 feet from the critical water level, where it could get into Butte’s groundwater. This new plant won’t drain the pit, but it will stop its rise.

“Maybe we want it 10 feet lower, we have the ability to drop it 10, 20 feet. We can find where the best spot for that water level is,” Thompson said.

ARCo hopes to have this 16,000 square foot facility completed here by the end of January and once the polishing plant is online, it can treat up to 10 million gallons of water a day. And this water, once safe enough, can be put back into Silver Bow Creek.

“This will be a filtering unit, so big filter units that the water will run through to remove particulate and polish really to ensure that we meet water quality standards in the stream,” said Burmeister.

Pure and clean former pit water could be running in the stream by next March.

Reporting by John Emeigh for MTN News