(CNN) Federal officials are expected to rule in the next month on a petition that could eventually lead to uranium mining around the Grand Canyon, which conservation advocates warn could irreparably pollute the region's limited groundwater supply.

While the petition is under consideration, the Commerce and Interior departments have made a series of decisions including reclassifying uranium as a critical mineral and developing a plan calling for increased domestic mining.

The departments' decisions have raised the concern of those who oppose mining in the region, who worry the administration may use the moves to justify modifying or rescinding the Department of Interior's 2012 decision that largely blocked mining on more than 1 million acres near the national park for 20 years. That 2012 decision, which was made to give the US Geological Survey time to study the unique impacts of uranium mining there, was upheld by the 9th US Circuit Court of Appeals in 2017.

"Uranium mining in the Grand Canyon region is an unnecessary threat to our tourism-based economies and the people who depend on the Grand Canyon," Amber Reimondo with the Grand Canyon Trust recently told a House subcommittee.

Interior Secretary David Bernhardt's current position on the ban is that he sees "no reason" to lift it, department spokeswoman Molly Block said Wednesday.

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