Pierre River Mine Project

WATER AENV SIRS 15 – 43
Section 12.1
AENV would readily detect any pond that had a water quality problem requiring
action. Shell currently monitors over 100 parameters at the Jackpine Mine
polishing pond outlets on varying monitoring schedules in a very comprehensive
monitoring program. Shell will comply with the water quality monitoring
regulatory requirements for all parameters.
Request 15c The water management systems are described as having a capacity to hold water
and achieve zero discharge for extended periods.
i. What are the anticipated holding times during the time of highest anticipated
flows and what are the flows expected?
ii. Where will the water be held during the extended periods of zero discharge
and what is the water holding capacity of the holding area(s)?
iii. What planning is in place to rehabilitate water quality in the unlikely event
that the water cannot be held for a sufficient time to mitigate water quality
issues?
Response 15c i. The water management systems described in the response to SIR 265b in the
May 2009 Pierre River Mine, Supplemental Information, Volume 2, refer to
areas with closed-circuit drainage. These areas do not include areas where
muskeg and overburden are being dewatered, as these flows would be
directed to the polishing ponds. For areas with closed circuit drainage, the
holding times are anticipated to be essentially unlimited in most cases. For
example:
• the EDTA is designed to withstand the probable maximum flood
• in the mine pit, all runoff is contained until it is actively pumped out of
the pit. The water holding capacity remains extremely large at all times,
even though it varies with the ever-evolving size of the mine pit.
• former mine pits backfilled with tailings (i.e., in-pit deposition cells), like
the active mine pits, are below grade until final capping. Like active
mine pits, water would be contained until pumped out of the cells.
• the plant site area would be at risk of releasing surface runoff to the
environment, but only in extreme events when ditch and pump systems
could be overwhelmed. During those events, water quality of the release,
with elevated levels of TSS, would be similar to the water quality of the
receiving environment.
• overburden disposal areas drain through collection ditches that
eventually make their way to the recycle water system
• areas reclaimed back to grade would send water to collection ditches that
would return to the water recycle system
12-2 Shell Canada Limited April 2010
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