Pierre River Mine Project

MINING AND PROCESSING ERCB SIRS 3 – 38
Section 4.1
• prestripping is used to increase construction quality overburden by advancing
the mining of suitable material during specific periods when there is a
construction material shortfall
The design philosophy for all engineered structures is to maximize the use of
available materials from the mine by tailoring construction material
specifications for the structure to match the mine materials available. Therefore,
the primary contingency for a construction material shortfall is to re-design the
engineered structure and the associated material specifications to use as much of
the available materials as possible.
Request 32d Discuss its impact on the tailings management plan, including impact on nonsegregating
tailings (NST) production, fines capture and mature fine tailings
(MFT) inventory.
Response 32d The contingency scenario where dyke structures are re-designed to optimize
material use would result in increased material quantities being placed in the
dykes, resulting in a revision to the integrated mine and tailings plan to
accommodate the adjusted material placement schedule.
Question No. 33
Adjustments to the design of engineered structures and the waste material
movement schedule are not expected to affect NST production, fines capture or
MFT inventory.
Request Volume 1, Section 4.1, Page 4-2, Supplemental Information Responses.
Shell states, “During operation of the ETDA (from 2018 to 2028), the TT will be
contained in a discrete cell within the ETDA, built using coarse tailings sand.
The TT cell within the ETDA will act as a designated disposal area for the
thickened tailings deposit.” In Volume 1, Section 10.1, Page 10-168, Table 219-
1, Supplemental Information Responses; it is indicated that the slurry density was
lower than 1400 kg/m3 (46% solids) more than a third of the time. Also, in
Volume 1, Section 10.1, Page 10-144, Supplemental Information Responses,
Shell states, “The timing required to make the TT deposits trafficable is
uncertain, as no full-scale stand-alone thickened tailings deposit has yet been
created, capped and made ready for reclamation in oil sands industry. However,
Shell understands the Directive’s requirement to have dedicated disposal areas
capped and ready for reclamation within five years after deposition activities
stop. Shell is evaluating, as a high priority, the means to shorten the time
required to make TT deposits ready for reclamation at the Muskeg River Mine
tailings test facility.”
4-32 Shell Canada Limited April 2010
CR029