6.0 TAILINGS STORAGE FACILITY
6.1
TAILINGS STORAGE FACILITY DESIGN
Tailings produced at the Upton Plant will be stored within an engineered, double lined tailings
facility, located just west of the plant (see Map A-1). The TSF is designed to meet the rules and
regulations of the WDEQ-LQD, Chapter 3, Section 2(h)(i) Noncoal Mine Environmental
Protection Performance Standards. Details of the preliminary design are presented in the
Rare
Element Resources Bear Lodge Project Preliminary TSF Design Report
prepared by Knight
Piésold
(see Attachment A).
6.2
GEOTECHNICAL ANALYSES
Geotechnical field exploration and laboratory testing programs were completed to support
conceptual and prefeasibility-level design studies of the TSF and Hydromet Plant foundations.
Golder completed the most recent program in the fall of 2013. Knight Piésold and Co. (Knight
Piésold) completed TSF field explorations and laboratory testing in 2011 and 2012. STRATA
(formerly CM-ET) completed the drilling services for Golder and Knight Piésold, and were also
responsible for the Hydromet Plant foundation explorations, testing and preliminary foundation
recommendations completed in 2012 and 2013. Based on the similarity of materials between
the plant and portions of the TSF, Golder included the geotechnical information generated from
the plant site explorations and soil testing with the TSF data used in evaluating site conditions.
6.3
TAILINGS OPERATION
The Upton TSF has been designed to operate as a dry stack facility and generally will consist of
tailings transport, deposition, and management; TSF embankment and liner construction; On-
going TSF maintenance and reclamation.
The waste material from the Hydromet Plant will be transported to the TSF using haul trucks.
Waste blending and neutralization of the waste streams will occur at the Plant prior to transport
to the TSF. Active disposal areas and reclamation of completed areas within the TSF will be
accessed by means of a network of haul roads established within and around the TSF footprint.
Tailings will be end-dumped and spread with a dozer. Compaction of the waste will occur
through material settlement as well as truck and dozer traffic associated with waste placement.
The TSF will be developed in a progressive sequence beginning at the north end of the facility
and expanding southward. The main TSF embankment along the eastern side and the north
and south abutment berms will buttress the waste for long-term stability and control contact
water within the TSF limits. As the TSF expands both vertically and laterally, the TSF liner
system will be expanded in a manner to create a continuous liner system in the TSF.
Intermediate berms will be constructed along the southern and western limits of each stage of
liner construction to facilitate liner connection, TSF expansions, provide toe support to the waste
slope during placement of the waste, and minimize surface water run-on into the active TSF
area from the area between the active area and the surface-water diversion ditch.
As part of the proposed liner system for the TSF, a 2- to 3-foot thick protective operations layer
is included immediately over the geomembrane to protect against damage prior to placement of
waste over the liner. No equipment will access the geomembrane liner directly and low ground
pressure equipment will be used to place the protective cover material. Should high ground-
pressure equipment be required to traverse over the operations layer prior to coverage with
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