Pierre River Mine Project

MINING AND PROCESSING ERCB SIRS 3 – 38
Table ERCB 4-1: Internal Drain Flow Estimate
Approximate Length of
Perimeter Cell Dykes
(m)
Flux
(m 3 /s/m)
Section 4.1
Total Expected Flow
(m 3 /d)
Thickened tailings 5,750 4.12E-05 20,500
Mature fine tailings 9,000 9.56E-05 74,500
Total Flow 95,000
Request 4b Discuss the estimated seepage volume in cubic metre/day/metre (m 3 /day/m) by
comparison to the seepage volume (m 3 /day/m) at the External Tailings Facility
(ETF) in the Muskeg River Mine.
Response 4b A comparison of the estimated seepage flux in cubic metre/day/metre (m 3 /d/m) at
the external tailings disposal area (ETDA) in the Muskeg River Mine and the
Pierre River Mine is presented in Table ERCB 4-2.
The Pierre River Mine theoretical flows are higher than those measured at the
Muskeg River Mine. This is expected, as the EIA predictions are based on
conservative assumptions that frequently over-predict actual values. Differences
in flux below the ETDAs at the Pierre River Mine and Muskeg River Mine result
from the following factors:
• the design basis of the Pierre River Mine flows assumed the pond to be at full
height, or about 45 m above original ground, whereas the Muskeg River
Mine pond is at a lower average elevation of 25 m above original ground,
over the 2006 to 2009 time frame that seepage flows were collected
• the theoretical flux from the Pierre River Mine is based on steady-state
assumptions, whereas the Muskeg River Mine has likely not reached this
state
Table ERCB 4-2: Comparison of Pierre River Mine Estimated Seepage Flux and Measured
Seepage Flux at the Muskeg River Mine External Tailings Disposal Area
Question No. 5
Pierre River Mine
Theoretical Flux
(m 3 /d/m)
Muskeg River Mine
Measured Flux
(m 3 /d/m)
Thickened tailings 3.6 0.5
Mature fine tailings 8.3 1.2
Request Provide the 3-D DXF electronic files for the top of the McMurray and the top of
the Devonian surfaces for the proposed project area.
4-4 Shell Canada Limited April 2010
CR029