Rosemont Copper continues aggressively moving dirt on its private land on the west side of the range. The Arizona subsidiary of Canada-based Hudbay Minerals continues to build “Copper World” for its planned pits, tailings, and leaching facilities.

Rosemont also continues to seek additional land on the north side of Copper World, in Corona de Tucson. It tells residents it wants to buy these lands as a buffer from the inevitable noise, light, and dust that the mine project will create. An unsightly power line running straight to the northern ridgeline would be built along Santa Rita Road.

In July, Rosemont broadly expanded the scope of Copper World, touting a “Made in USA” copper cathode production plan that claims to be greener than its previous plan. That process is expected to generate 140,000 annual tons of sulfuric acid. Looking at the production data in the annual water use, one can calculate water use to at least be twice than the current 6,000 acre-feet a year it’s currently permitted to pump from wells in Sahuarita.

There are practical limits to what can be done to stop work on private land. But once Copper World has a nexus to roads, air, views and the Santa Cruz River, this project becomes a community issue. It is impossible to contain a mine project of such a size with no impact on public lands and natural resources.

Rosemont needs proper permitting and genuine outreach to frontline communities in the months and years ahead. Several ephemeral washes run directly from the proposed mine site to the Santa Cruz. The risk of runoff contamination will become very real.

The U.S. needs copper for electric vehicles and a green economy. But there is a large global inventory of copper, according to U.S. Geological Survey data. Copper is also highly recyclable. It’s absurd to destroy an intact Sky Island range that sustains us, and wildlife, and hosts the Arizona National Scenic Trail. The Santa Ritas’ iconic northern ridgeline would be obliterated under the mine plan.

Residents in these frontline communities should know that Rosemont plans to produce cathodes that require a massive amount of sulfuric acid. Acid production requires burning sulfur, which, in turn, becomes sulfur dioxide, then sulfur trioxide. When that molecular compound is dissolved in water, it forms sulfuric acid. Sulfur dioxide, a gas, is an eye, nose, and throat irritant linked to lung cancer and cardiovascular disease. And sulfur trioxide is carcinogenic to the human respiratory system. A thousand feet above the Santa Cruz Valley, temperature inversions will expose residents to these potential hazards, which certainly do not improve residents’ quality of life or their home values.

Hiking Madera Canyon or the Arizona National Scenic Trail, one meets people from across the country and worldwide, drawn to this and other scenic Sky Island ranges. Magnificent landscapes, natural history, and biological diversity are the attractions. Unfortunately, Copper World will trade off spectacular nature for a few hundred jobs and profits to non-local investors. These mountains are worth preserving and protecting for future generations.