The federal Clean Water Act Permit issued by the U.S. Army Corps of Engineers had given the Rosemont mine the right to discharge dredged and fill material into about 48 acres of washes as part of the mine’s construction in the Santa Rita Mountains southeast of Tucson.

A federal Clean Water Act permit authorizing the construction of the Rosemont Mine has been suspended due to a recent court ruling stopping other work on the project.

The U.S. Army Corps of Engineers wrote to Hudbay Minerals Inc. last Friday that effective immediately it is suspending the permit it approved for the mine in March.

The permit gave Toronto-based Hudbay the right to discharge dredged and fill material into about 48 acres of washes for construction of its open-pit copper mine in the Santa Rita Mountains southeast of Tucson.

In its letter to Hudbay, the Corps noted that when it granted the permit in March it at the same time also formally adopted the final Rosemont environmental impact statement. The Forest Service had approved the statement in 2013.

But in his July 31 ruling overturning the Forest Service’s decision approving the mine, U.S. District Judge James Soto also vacated that final environmental report, wrote Brigadier Gen. Peter Helmlinger, commander of the Corps’ Northwestern Division.

The permit suspension means the mine may now need two rounds of federal approvals before construction can start on the $1.9 billion project.

If the court ruling holds up on appeal, the Forest Service most likely would have to redo its Rosemont environmental report, and the Corps would have to reinstate the permit.

Hudbay had previously scheduled construction work to start Aug. 1. It needs approvals from both the Corps and the Forest Service because the two agencies control different aspects of the project.

The Corps’ authority extends only to Clean Water Act-related matters, while the service’s authority covers most other aspects of the mine.

“Because the Corps relied on the Final EIS in approving the permit, I have determined it is in the public interest to suspend” it, in accord with agency regulations, Helmlinger wrote to Kathy Arnold, environment director for Hudbay’s Arizona Business Unit.

“You are not authorized to discharge dredged or fill materials in waters of the U.S.,” wrote Helmlinger, using the formal term for rivers and washes that fall under federal Clean Water Act regulation.

In a statement, Hudbay said the Corps’ latest decision was “anticipated” due to the earlier federal court ruling.

The mining company continues preparations relating to an appeal of the court ruling, and expects the Clean Water Act permit will be reinstated “upon the successful outcome of the appeal,” Hudbay said.

Corps spokesman Mike Petersen said the agency can’t speculate on when and how a decision would be made if Soto’s ruling is overturned.

Clean Water Act permits are known as 404 permits.

Gayle Hartmann, president of the Rosemont opposition group Save the Scenic Santa Ritas, said in a statement, “It is common sense that the Army Corps of Engineers has suspended Rosemont’s 404 permit. Now it is absolutely clear that Hudbay cannot engage in any destructive activities in and near the Santa Rita Mountains.”

Contact reporter Tony Davis at tdavis@tucson.com or 806-7746. On Twitter@tonydavis987