Closure of Mission Tailings Facility

Location

Arizona, USA

Client

Asarco Mission Trust Panel

Project Description

GSA conducted an extensive material characterization program to identify soil cover material from both native and waste rock sources, and assisted on the closure design for 1,200 acres of tailings impoundments and 800 acres of waste rock facilities. Variable depth cover systems were designed to support vegetation and minimize net percolation on flat areas. Side-slope reclamation was designed to reduce erosion via rock armor. Angle of repose slopes were reduced to 3:1 ant then covered with one-foot of alluvium overlain with one-foot of benign waste rock as a rock armor. The project was undertaken with a finite and relatively small capital budget and successfully completed in 2010 on budget and to the satisfaction of all stakeholders. GSA is currently conducting long-term vegetation success monitoring.

Project Highlights