Last month, the Wisconsin Legislature repealed what was known as the “Prove it First” law, which has put a freeze on sulfide mining in the state since 1998.
Under the “Prove it First” law, the Department of Natural Resources could only grant sulfide mining permits to companies which had operated for 10 years and then closed for 10 years without polluting ground or surface water with acid drainage or heavy metals. This law essentially created a sulfide mining moratorium in the state, since no companies were able to prove they met this requirement.
The repeal of this law opens Wisconsin to the possibility of Sulfide Mining for the first time in nearly two decades. Supporters of the repeal, feel that the mining moratorium posed an un-necessarily stringent regulatory standard and hope that relaxed mining regulations will bring more mining jobs into the state.
With the lifted moratorium, sulfide mining could come to central Wisconsin.
Marathon County contains the Reef Deposit, one of the four metallic mineral deposits that the DNR lists in Wisconsin. However, local politicians are wary of the prospect. Marathon County board has investigated the possibility of creating a local mining ordinance to offer the county additional protection given the possibility of a mine at the Reef Deposit.
Earlier this fall, a group of mayors from three central Wisconsin communities, including Mike Wiza, mayor of Stevens Point, published a letter in opposition to the bill. They said the bill, “will have devastating impacts on communities in our state, polluting local waterways and soil that support tourism, agriculture, and jobs in our communities.”
Many environmental groups have voiced the same concern, that sulfide mining will pollute water.
Ron Crunkilton, fisheries and water resources professor, said that sulfide mining can contaminate water by creating sulfuric acid, which occurs when sulfur in the mine tailings is exposed to oxygen and water. Although any mining can cause pollution, sulfide mining is particularly risky because large amounts of sulfide ore must be crushed to obtain the desired minerals, usually gold, silver, copper or zinc, contained within the rock. Since the percent recovery of these minerals can be very low, the process can generate large amounts of waste.
Crunkilton said that if sulfuric acid reaches streams, the water can in some cases become so acidified that it is uninhabitable for fish. Furthermore, this acidification continues as long as the sulfur remains exposed to air and water, creating impacts that can last for decades and longer.
Crunkilton said what is more concerning is that the sulfuric acid can dissolve metals normally tied up in rock, allowing them to move with water into lakes, streams and the ground. These can include heavy metals which create a human health hazard when they reach the groundwater.
“Once it’s in the ground it can be there for really generations… it’s not really something you can restore after you have ruined a resource,” Crunkilton said.