By Brenna Goth, The Republic, azcentral.com,

A 20-year ban on uranium mining near the Grand Canyon will remain in place after the U.S. District Court in Arizona ruled Tuesday against mining groups that sued the federal government.

Mining associations and other groups with a stake in the industry argued that the U.S. Department of the Interior had erred in a 2012 decision to ban new mining for 20 years on more than 1 million acres of public land near the national park. They argued the ban was based on “overly cautious,” speculative environmental risks. The withdrawal decision was based on studies assessing potential impacts on water, soil and other resources.

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The ban prohibits the exploration and development of new claims but does not affect previously approved mining.

Judge David Campbell heard oral arguments on Sept. 9 and ruled Tuesday that then-Secretary of the Interior Ken Salazar did not violate the law when he chose to “err on the side of caution in protecting a national treasure,” even if he did not have “definitive information.”

An Interior Department spokesperson declined to comment.

A coalition of environmental groups and the Havasupai Tribe joined the lawsuit to defend the ban, sayingthe effects of uranium mining are long lasting and may not be fully known for decades.

“This is a great day for the Grand Canyon,” said Ted Zukoski, the lawyer representing those groups, adding that the department “really did its homework” with the risk assessments.

Mining groups have 60 days to appeal.

Laura Skaer, executive director of one of the plaintiffs, the American Exploration and Mining Association, said she would need time to review Campbell’s reasoning before deciding any next steps.