■ Disturbing more than 5,400 acres of grasslands, woodlands and riparian areas could take a significant toll on plants and wildlife, the Rosemont final environmental impact statement says. It predicts impacts from dust, noise, night lighting and vibration, reduced surface water flows, drying of riparian areas, springs and stock tanks, and blading and filling of canyons.
■ The Barrel Alternative (see glossary) would disrupt six wildlife corridors where mountain lions, jaguar and other animals roam from one mountain range to another, says the EIS, although it would help three other corridors. Nine protected species and more than 40 others with special status could be impacted.
■ Compared with other options, the Barrel Alternative would clear less vegetation and aquatic habitat, stop the least surface water from flowing downstream, have the least impact on wildlife corridors and be least likely to contaminate water, the Forest Service says.
■ The EIS lists nearly 60 mitigation and monitoring measures. They include preserving 4,500 acres, reducing dust by paving dirt roads, relocating some species and using dry stack tailings (see glossary). Rosemont Copper has promised $10 million more to protect and monitor wildlife.