Closure of Miami 19-34-35 Dump

Location

Arizona, USA

Client

Freeport-McMoRan Inc./ MWH Americas, Inc.

Project Description

GSA developed and evaluated several alternative cover system designs for the closure of this 180 ha copper heap leach dump facility. An extensive mine waste and borrow material characterization program with integrated in-situ and laboratory hydraulic property testing was implemented to identify potential cover system borrow material for growth media and erosion resistant side-slope material. Several alternative cover system designs were evaluated based on site conditions, available borrow materials, surface water management, regulatory constraints, and costs. Unsaturated flow modeling was used to predict the relative cover system performance between the alternative designs and an optimal closure cover system design was selected. Heap leach drain-down estimates were also prepared to assess potential post-closure water treatment needs. Study results have been used to develop a final closure plan for the facility.

Project Highlights