How mine pit lakes could help to tackle climate change – Is Butte’s Berkeley Pit a Candidate?

Spotted: When mines are closed, the massive open pits will gradually fill up with groundwater, rain, and water run-off from the land’s surface to create mine pit lakes. The water in these lakes is mostly low-quality, contaminated, and acidic, meaning they have limited beneficial uses. But what if they could be used to capture carbon?

In a low-cost, low-energy process, US company Aquarry adds alkalinity to mine pit lakes to help them capture and store CO2 over the long term. The ocean is the world’s biggest carbon sink, and many scientists have already suggested the possibility of speeding up natural ocean alkalinity enhancement. IN this process, alkaline molecules produced through the gradual weathering of rocks react with CO2 in the ocean to create stable forms of carbon to accelerate the removal of atmospheric CO2.