Under current law, a mining company must prove a sulfide mine can operate for 10 years and be closed for another 10 without polluting groundwater or surface waters with acid rock drainage. That legislation was passed with near-unanimous, bipartisan support in 1998 and signed into law by Republican Gov. Tommy Thompson.

Walker signed the bill in Rhinelander, with the support of several Wisconsin natives and residents who say they hope to work in the mining industry in their home state thanks to the bill's passage.

Taylor Pitlik, 22, of Sugar Camp, is a senior in Michigan Technological University's mining engineering program. A fourth-generation aggregate miner, she said she looks forward to working in her home state.

Several other students in mining and geological engineering programs have similar goals, according to the Natural Resources Development Association.

In a statement, Americans for Prosperity-Wisconsin director Eric Bott said the law will bring back "good-paying, family-sustaining, blue-collar jobs" to northern Wisconsin.

Opponents of the legislation, like Sen. Jon Erpenbach, D-Middleton, have argued that if a sulfide mine could operate safely, the existing law wouldn't have prevented it from doing so in Wisconsin.