The Bureau of Land Management proposed renewing hardrock mineral leases in the Rainy River Watershed near the Boundary Waters Canoe Area Wilderness on Thursday, initiating a 30-day comment period.

The federal leases belong to Twin Metals, a wholly owned subsidiary of Chilean mining conglomerate Antofagasta, which is planning a copper mine along the Kawishiwi River near Ely that critics say could send tainted runoff into the BWCAW.

Newsletter signup for email alerts

The BLM's proposal includes new stipulations on the leases in its "proposed action" while the "no-action alternative" would renew the leases under the same conditions as the leases' last renewal in 2004.

Proposed changes were outlined in an updated environmental assessment released Thursday. Comments on the assessment will be accepted through Jan. 22.

The federal mineral leases were first issued in 1966 and renewed in both 1989 and 2004. Twin Metals filed for the third renewal of the leases in 2012.

Twin Metals' mineral leases were rescinded by the Obama administration in 2016 as the U.S. Department of Agriculture said it was too close to the BWCAW. The leases were returned by the Trump administration in May.

The Department of Agriculture opened the door for mineral lease renewals in September when it ended a mineral withdrawal proposal in the Rainy River Watershed and Superior National Forest initiated by the Obama administration.

In a statement, Gov. Mark Dayton said the decision to renew leases would endanger the BWCAW.

"Driven by greed and willful ignorance, the Trump Administration has consistently demonstrated an insatiable appetite for selling out to large corporate interests, at the expense of our environment. Yet again, they have pulled out all the stops to kowtow to the financial interests of a large Chilean corporation with a terrible environmental record," Dayton said.

In a statement, Twin Metals said the public comment period would allow for greater public input and transparency.

"Twin Metals looks forward to the timely and proper completion of the lease renewal process. We continue to look forward to the opportunity to present a formal Mine Plan of Operations for review by the federal government," Twin Metals said.

According to the BLM, written comments should be addressed to MN Hardrock Lease Renewal EA Project Manager, Northeastern States District Office, 626 E. Wisconsin Ave., Ste. 200, Milwaukee, WI 53202.