The Draft EIS describes the process undertaken by the USDA Forest Service, to evaluate the issues related to and predicted effects of the submittal by Resolution Copper's mining GPO, and legislatively-mandated land exchange.
A variation of the proposed action described in the May 9, 2016, version of Resolution Copper’s General Plan of Operations, this alternative would include a split-stream tailings processing method with two tailings types.
Shares several similarities with Alternative 2; one key difference is it proposes to reduce the amount of water retained in non-potentially acid generating (NPAG) tailings as well as reduce seepage potential through on-site thickening of NPAG tailings and ‘Thin-lift’ deposition.
The only alternative proposing to use filtered tailings instead of slurry tailings. Conveyors and mobile equipment would mechanically deposit potentially acid generating tailings and non-potentially acid generating tailings in two separate, adjacent tailings storage facilities.