##  [Integrated Surface-subsurface Water and Solute Modeling of a Reclaimed In-pit Oil Sands Mine: Effects of Ground Freezing and Thawing](/resource/integrated-surface-subsurface-water-and-solute-modeling-reclaimed-pit-oil-sands-mine) 

Organization

[University of Waterloo](/organization/university-waterloo)

[Syncrude Canada Ltd. (SCL)](/organization/syncrude-canada-ltd-scl)

[ARKK Engineering Corporation](/organization/arkk-engineering-corporation)

 

 

Resource Type

[Peer reviewed article](/taxonomy/term/37)

 

 

Author(s)

Ranjeet Nagare

Young-Jin Park

Rob Wirtz

Dallas Heisler

Glen Miller

 

 

Original Authors

Ranjeet Nagare

Young-Jin Park

Rob Wirtz

Dallas Heisler

Glen Miller

 

 

Resource Date:

2022

 

Page Length

18

 

 

The upland and wetlands substrate in reclaimed oil sands landforms will be constructed of post-mining materials with an objective of replicating the landscape and hydrology of the surrounding boreal systems. Porewater in these materials contain elevated levels of salts and other solutes. Water quality will govern the success and sustainability of the reclaimed landscape. Tightly coupled water and heat dynamics control water and solute movement in boreal systems. We used three-dimensional integrated surface-subsurface flow and chloride transport models with and without ground freezing-thawing to compare performance of an in-pit oil sands mine currently being reclaimed.  
New hydrological insights for the region: Transient simulations under wet/dry climate cycles suggest that the reclaimed landform will shed water only during wet years. Annual water balance with and without coupled heat dynamics is identical. However, the three-dimensional representation of ground freeze-thaw results in reduced snowmelt infiltration, summer groundwater table, and solute release during winter. The outcome is increased spring runoff, 20% decrease in chloride  
mass release over simulated eight-year wet climate cycle and relatively reduced summer runoff. The model results suggest that (1) coupled heat dynamics should be considered for detailed evaluation of reclaimed in-pit landforms at finer time scales, and (2) modeling reclaimed landforms without freeze-thaw provides conservative annual solute release estimates, which is appropriate for coarse site-wide models.