Canadian mining company Hudbay Minerals is allowed to continue work on a new copper mining project slated for a slope of the Santa Rita Mountains in southern Arizona. 

Hudbay Minerals was planning a massive, open-pit copper mine called Rosemont in the Santa Ritas on a swath that is largely U.S. Forest Service land. But that was blocked by court order in 2019, then reinforced on appeal this year. U.S. District Judge James Soto ruled the proposed mine's plan to dump waste material into federal water was in violation of a key clean water permit regulated by the Army Corps of Engineers.

The company surrendered that permit and began working on a different stretch of the Santa Ritas, this time on private land that it owns. It says it's carrying out exploratory drilling projects and clearing land there for a new project called Copper World. It surrendering the Army Corps permit, Hudbay argued it was not beholden to the agency's regulations on the new stretch. 

Conservation groups asked the court to grant an emergency stop order this month, arguing because Hudbay doesn’t have the proper water permit for Rosemont, it shouldn’t be able to dump material into mountain streams at the Copper World location. 

But Judge James Soto denied that motion this week, saying the Army Corps of Engineers doesn’t have the authority to regulate Hudbay’s water activities on this swath of land, because the company has already surrendered the permit.

Hudbay says it's currently carrying out a Preliminary Economic Assessment of Copper World that is set to be complete later this year.