The formal objection period for the proposed Rosemont Copper mine's final environmental impact statement ends Friday, capping a 45-day period for public response to the Coronado National Forest's statement of how the mine might affect the environment.

The statement was prepared by the Coronado National Forest after years of review and edits to draft environmental statements, said Jennifer Ruyle, a natural resources officer with the Coronado National Forest.

"It's our job to do the very best job we can in disclosing the impacts that the project would have and requiring any mitigation that's within our authority," she said.

Rosemont and opponents have disagreed about the possible environmental impacts of a mine on the eastern side of the Santa Rita Mountain range, east of Green Valley. The disagreements range from what could happen to water resources, animal habitat, and migration patterns.

"The final environ impact statement was a culmination of a lot of input from everyone" said Kathy Arnold, vice president of environmental and regulatory affairs at Rosemont Copper Company.

One of the groups objecting to the statement is the Pima County Board of Supervisors, which voted 4-1 last week to file an objection. Supervisor Ally Miller opposed.

Supervisor Ray Carroll said the majority of the board has opposed the mine for years because they think the company isn't going as far as it should to reduce environmental impact. The board and the company agreed to mitigation efforts in 2006, he said.

"We laid out some issues, five successful mitigation attempts that they agreed to at one point but still to this day we have not seen the five accepted agreements", in the documents, Carroll said.

The supervisors' objection is not just as the Board of Supervisors, but also as the Flood Control District Board, which regulates waterways in the county.

Carroll is concerned, he said, about the impact on the water table because the mine will use potable water, not water from the Central Arizona Project.

But Rosemont had no choice in that matter, Arnold said, because it is restricted from using CAP water.

The public has until Feb. 14 to submit objections to the Coronado National Forest's Environmental Impact Statement.

To lear more about history of mining in Arizona, you can also watch an excerpt from an hour-long documentary "Under Arizona" by Eight, Arizona PBS in Phoenix.