Pierre River Mine Project

WATER ERCB SIRS 46 – 79
Question No. 58
Section 7.1
quality constituents and that changes in water quality in the Athabasca River
would have negligible effects on aquatic, human and wildlife health.
Request Volume 2, Section 21.1, Page 21-14, Supplemental Information Responses.
Shell states, “The rates of inflow presented for the Pierre River Mine LSA
include lateral groundwater inflows to the LSA from up gradient areas.”
58a Describe the simulation of lateral recharge from upgradient areas in the model.
Response 58a Lateral groundwater inflow rates to the local study are (LSA) were calculated
based on the simulated groundwater flows across the LSA boundaries in the
regional groundwater model (see EIA, Appendix 4-1, Section 1.2.4.4, page 94).
In the model, groundwater levels from the regional model were represented as
general head boundaries at the lateral boundaries of the Pierre River Mine local
model in layers 4 (base of Quaternary), 9 (Basal Aquifer) and 12 (Methy
Formation).
Question No. 59
Request Volume 2, Section 21.1, Page 21-59, Supplemental Information Responses.
Shell states, “The Eymundson Sinkholes do not appear to have a marked
influence on the groundwater flow pattern in the Quaternary deposits.”
59a Provide the technical justification for this assumption including any geophysical
surveys or detailed Karsts delineation studies.
Response 59a The technical justification for this statement is the groundwater flow patterns
illustrated in Figures 37 and 38 of the Hydrogeology Environmental Setting
Report (WorleyParsons Komex 2007). Based on available groundwater-level
information from piezometers in Quaternary deposits near the Eymundson
Sinkholes, the groundwater flow patterns within and outside of the Eymundson
Sinkholes Environmentally Sensitive Area (ESA) are similar. Overall, the
groundwater flow patterns in the Quaternary deposits reflect topographical
control and do not suggest any considerable alteration of the regional flow
pattern within or near the Eymundson Sinkholes ESA.
April 2010 Shell Canada Limited 7-13
CR029