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.
This alternative allows for a comparison of the impacts of slurry tailings if placed in a flatter, alluvial setting instead of an upland wash or canyon.
The location for this alternative would enable use of cross-valley embankments/dams requiring less fill to retain tailings compared to a ring-like impoundment, simplifying construction and operations.
The Forest Service has completed the Scoping Report for the EIS that includes information on the overall scoping process and what concerns were presented by the various participants. The next step in the EIS process is alternatives development, which is required to investigate alternatives to various aspects of the Proposed Action.
The Forest Service is hosting workshops to solicit input on the relative importance of a variety of environmental and social criteria that they will use to evaluate alternative tailings facility locations. The Forest Service has scheduled in-person and online workshops.
The Forest Service held workshops to 1) update the public on the status of the EIS process 2) describe the alternatives development process, and 3) solicit input on the criteria being used to evaluate alternative tailings storage facility locations.
The Southwestern Region Office of Lands and Minerals Management is overseeing and administering the land exchange and appraisal process which includes the 2,422-acre Oak Flat Federal Parcel. All questions about the land exchange and appraisal process should be emailed to SM.FS.rcexinfo@usda.gov
Programmatic Agreement Info
To comply with Section 106 of the National Historic Preservation Act, the Tonto National Forest developed a Programmatic Agreement (PA) and included it in Volume 5, Appendix O of the final EIS. The PA was created in cooperation with the Advisory Council on Historic Preservation, the State Historic Preservation Office, tribes and other consulting parties. The PA contains an agreed upon process for identifying, evaluating and addressing adverse effects to historic properties associated with this undertaking.
