The long saga of the Rosemont Copper project south of Tucson, AZ continues as four environmental groups have sued the U.S. Forest Service in an effort to block the development of the mine by claiming it will violate laws and regulations protecting the water flowing in neighboring streams.

In June, the U.S. Forest Service issued a final decision approving the mine plans that were submitted by owner HudBay Minerals. Coronado National Forest Supervisor Kerwin Dewberry approved the mine in June, selecting a specific mine layout out of several alternatives proposed He said, as did his predecessor Jim Upchurch’s draft approval in 2013, that the chosen layout will have fewer environmental impacts than any other alternative the service analyzed.

The Forest Service has said it couldn’t legally bar the mine because of several federal laws, dating back to 1872, that call upon the federal government to open up its lands to mineral production.

The Arizona Daily Star reported that the lawsuit — filed by the groups Save the Scenic Santa Ritas, the Center for Biological Diversity, the Arizona Mining Reform Coalition and the Sierra Club’s Grand Canyon chapter — says that stance is legally wrong.

The mine would violate at least 10 environmental laws, regulations, standards and protections of federal water rights, the lawsuit says. In part, the groups say the violations will occur because the mine will reduce the amount of water flowing in the streams and hurt water quality.

This is the second suit filed this year seeking to stop Rosemont. In September, the Center for Biological Diversity sued the U.S. Fish and Wildlife Service over its determination that the mine won’t jeopardize or illegally damage the habitat of the endangered jaguar. The Forest Service is also a defendant.

In a statement, Hudbay officials expressed confidence that the Forest Service will prevail in the lawsuit, due to “the rigorous diligence shown by the Forest Service in fulfilling its responsibilities during the permitting process.

“Rosemont has been under review for nearly a decade and considered in that time by 17 cooperating agencies, mostly at the federal and state levels,” Hudbay said.

A third legal challenge is likely to an upcoming decision by the U.S. Army Corps of Engineers on whether to grant Rosemont a separate permit to operate the mine under the federal Clean Water Act.

Environmentalists as well as Hudbay officials have already made it clear they’re likely to challenge the decision, depending on which way it goes. The Army Corps’ San Francisco division office has reviewed the case for more than a year following a recommendation from lower-level Corps officials to deny the permit.

In the past, Forest Service officials have said they believe the mine would meet environmental laws in part because of a very long list of mitigation measures they and other agencies have imposed on it.

Hudbay CEO Alan Hair, in a Nov. 2 conference call with industry analysts, said about the pending Army Corps decision, “We respect the fact that this is a scientific and technical process and that good science will prevail. ... We do strong engagement with the regulators and are looking to have a good product in both the 404 (Clean Water Act permit) and mine plan of operations when they’re complete.”