The U.S. Supreme Court on Monday declined to hear a case that challenged a uranium mining ban on land surrounding Grand Canyon National Park.

In 2012 the Obama administration banned new mining claims on 1 million acres outside the national park.

In March the mining industry asked the Supreme Court to review the ban, saying it was based on an unconstitutional provision of federal law. The National Mining Association's Ashley Burke says the ban is unwarranted and makes the U.S. even more dependent on imports.

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But Taylor McKinnon, a spokesman for the Center for Biological Diversity, says mining uranium is too risky. When uranium ore is mined, it becomes water-soluble.

"There's a real concern that the uranium and other contaminants could be swept deep underground during flood events and permanently contaminate those aquifers," McKinnon said. "The problem is if that were to happen, there's really no way to fix it. Mining is gambling with the irretrievable damage of groundwater that our region has depended upon and will depend upon for generations to come."

The high court's decision is a victory for environmentalists as well as the Havasupai Tribe, which lives in and around the Grand Canyon. They have been fighting to protect their drinking water as well as their sacred sites for decades.