Abstracts

Steven G. Shikaze & Benjamin L. Bolger
Matrix Solutions Inc., Breslau, Ontario, Canada
Mark King
Groundwater Insight Inc., Halifax, Nova Scotia, Canada
Hector Maya
Rockwood Lithium Ltd., Santiago, Chile
Catalina Orb, Jorge Garcia Tascon, & Jaime Solari
SGA, Santiago, Chile
The Salar de Atacama contains one of the world’s largest lithium brine deposits. The
salar (dry salt lake) is located in the Andes in northern Chile, approximately 1,500 km
north of Santiago, near the Chile/Argentina/Bolivia border. Lithium is mined from the
salar by extracting (via pumping) the high salinity brine (over 300,000 mg/L total dissolved
solids) from the geologic materials in the nucleus of the salar. Around the border
of the nucleus, shallow lagoons are a nesting habitat for migratory flamingos, and therefore,
pumping of the brines in the nucleus must consider the potential impact on water
levels at these lagoons.
To examine this impact in the nucleus, a numerical model study has been carried out.
Because the lithium-rich brines in the salar have a fluid density much higher than the
surrounding fresher water, the program SEAWAT was used to simulate brine pumping
in the nucleus, and its effect on (1) the groundwater levels around the lagoons, and (2)
the location of the brine-freshwater interface. The SEAWAT model, which was developed
in parallel with a three-dimensional MODFLOW model for groundwater flow,
was used to examine the sensitivity of model parameters such as hydraulic conductivity
(K), recharge (which is very low over the nucleus), and evaporation (which is very high).
285 - A review of key groundwater issues, eight years after
the start of dewatering at the Victor Diamond Mine, James Bay
Lowlands, Ontario
Simon Gautrey
Amec Foster Wheeler, Hamilton, Ontario, Canada
The Victor Diamond Mine is an open pit mine located in the James Bay Lowlands, approximately
90 km west of the community of Attawapiskat and 120 km east of the Ring of
Fire. The mine is surrounded by contiguous wetlands that extend for thousands of square
kilometers. The limestone bedrock at the site is prone to karst development and the mine is
located within a few kilometers of two rivers, one of which, the Attawapiskat River, is more
than 500 m wide. This submission will review two key issues related to impacts of dewatering
to the wetlands and rivers that were raised as concerns prior to the start of mining and
compare them to observed conditions after eight years of dewatering.
From the beginning, it was known that mining would require large scale dewatering. Both
the mine investors and the Attawapiskat First Nation, on whose traditional lands the mine
is located, needed to know how much dewatering was going to be required and what
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