A mine blast in the Burro pit sends dirt flying into the air at the Johnson Camp mine, Thursday April 16, 2009 in Dragoon, Ariz.

James S. Wood / Arizona Daily Star 2009

■ The National Park Service is concerned about pollution from mine vehicles, dirt roads, crushers and conveyors. But the Forest Service says the mine will meet air quality standards for six pollutants, including nitrogen oxide, particulates and sulfur dioxide.

■ The EIS and the park service agree the mine would worsen visibility at Saguaro National Park – East and West and raises the possibility that visibility there wouldn’t meet state regional haze goals. But the service says that won’t violate federal standards. The mine won’t face regulatory controls over visibility until 2018, when the state must turn in its next regional haze control plan.

■ The park service wants additional mitigation. It’s also concerned that nitrogen emissions on Saguaro Park-East, could fuel buffelgrass and other non-native grasses that drive out native plants.