Anti-mining groups and politicians rail against copper nickel mining but never mention the six-year environmental impact statement that was already completed.

In December 2016, President Barack Obama signed an executive order to withdraw 234,328 acres in the Superior National Forest from mining exploration and denied Twin Metals the renewal of its leases.

Mining opponents never mention that according to the Federal Register, a study was to take "up to two years" to determine if a 20-year ban should be placed on future mining and exploration.

When President Donald Trump took office in January 2017, that two-year study began. It ended in 21 months, with no new science to require a 20-year ban on copper nickel mining.

U.S. Rep. Betty McCollum ("McCollum fighting for mine study," May 21) doesn't acknowledge that the process is being followed, not only by Twin Metals, but also by the Trump administration. The ones who are continually sidestepping the process are the anti-mining groups, politicians like McCollum and the Obama administration, which never asked for input from state, county or city officials, or had a public comment period before issuing the executive order withdrawing thousands of acres from future mining.

McCollum and the anti-mining groups ignore the National Materials and Minerals Policy, Research and Development Act — referred to as the "Minerals Policy Act." At the time of its passage in 1980, Democrats held a solid majority of both houses in Congress, and President Jimmy Carter signed the act into law.

The Minerals Policy Act clearly states we must simultaneously protect the environment and develop minerals:

"The federal government, as a fundamental aspect of national minerals policy, must seek balance between the environmental, health and safety statutes and regulations … and the need to ensure the reliable availability of strategic and critical minerals."

In other words, the law mandates a balance between mining and the environment, and directs the secretaries of Agriculture and Interior to consider the vital importance of minerals and give equal weight to mineral production and environmental protection.

It should be noted that the Rainy River Gold Mine, between Baudette, Minn., and Fort Frances, Ontario, is in the very same Rainy River Watershed as Twin Metals' proposed underground mine. Also ignored by all is the fact that the high sulfide Dunka Pit has been monitored since 1977 without any impact to Birch Lake or to the Boundary Waters Canoe Area Wilderness. In fact, Cleveland Cliffs-Dunka Pit recently received an award from the Minnesota Pollution Control Agency for its wastewater treatment.

Twin Metals has formally received the renewal of its mineral leases and we thank the Trump administration, the Western Caucus, U.S. Reps. Pete Stauber and Tom Emmer for their help in getting this done.

Twin Metals will be submitting its formal underground mine plan to state and federal regulatory agencies in the coming months. A lengthy and costly multiyear EIS will then be conducted.

Today's environmental regulations tightly restrict how mines are designed and operated. State and federal agencies require strict adherence to regulations surrounding key environmental issues, including surface water and groundwater quality, threatened and endangered species, air quality, plant life, wetlands and more.

The Twin Metals Project must meet or exceed environmental requirements and receive permits to be authorized to move the project forward.

Nancy McReady is president of Conservationists with Common Sense. Gerald Tyler is chairman of Up North Jobs. Mike Cole is CEO of Minnesota Miners.