Abstracts

171 - Evaluating the Effects of Increased Lithium Brine
Extraction from the Salar de Atacama: Conceptual and Numerical
Groundwater Models
Mark King
Groundwater Insight, Inc., Canada
Steve Shikaze
Matrix Solutions Inc., Canada
Hector Maya
Rockwood Lithium, Chile
Jaime Solari & Laura Vitoria
SGA, Chile
Most of the world’s lithium reserves occur in dry salt lakes (salars) located in a section of
the high Andes near the common borders of Chile, Argentina and Bolivia. Almost all of
the current lithium production from this region originates from two companies operating
in the Salar de Atacama. One of these companies, Rockwood Lithium, is currently seeking
government approval to increase its brine production rate. This paper provides an overview
of conceptual and numerical groundwater models constructed to evaluate the potential
impacts of this proposed increase in brine extraction.
The Salar de Atacama is located in an extreme desert environment, with annual precipitation
of less than 50 mm/yr. The lithium-containing brine is located under the flat surface
of the salar, in a porous evaporite matrix. The nucleus of the salar contains brine with as
much as ten times the dissolved solids content of seawater. Meanwhile, subsurface waters
in the outer border areas of the basin are relatively fresh, and are used as a freshwater
resource. A key environmental feature of the Salar de Atacama are the shallow border lagoons,
which are an important breeding habitat for migratory flamingoes. Consequently, a
key criteria for any increase in brine pumping rates is that the water levels in these shallow
border lagoons remain unaffected.
In this environment of extreme salinity contrasts, the effects of increased brine pumping
were evaluated with the numerical model SEAWAT. This numerical code has the capability
of simulating density-dependent flow, which is a key process in the salar border area,
where there is an interface between subsurface brines and saline to fresh waters. In this
evaluation, local-scale SEAWAT models were coordinated with a regional-scale, flow-only
MODFLOW model. This paper presents an overview of the conceptual and numerical
approaches used to evaluate this unique and complex environment.
131 - A Conceptual Model for Pore Water Release from Coal Waste
Rock Piles in the Elk Valley, British Columbia, Canada
Terryn Kuzyk, S. Lee Barbour, & M. Jim Hendry
Department of Civil and Geological Engineering, University of Saskatchewan, Saskatoon,
Saskatchewan, Canada
118 IAH-CNC 2015 WATERLOO CONFERENCE