A study to evaluate the performance of reclamation soil covers placed over an oil sands fluid coke deposit
Date
2012-05-01
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Degree Level
Masters
Abstract
Coke, a by-product of petroleum extraction from oil sands, is considered a potential energy
source and must be stored within the reclaimed landscape in a manner that allows it to be
recovered in the future. Syncrude Canada constructed two instrumented watersheds at the
Mildred Lake Settling Basin (tailings management facility) to study the effects of coke in the
environment. The watersheds consisted of a “shallow” and a “deep” cover system with nominal
thicknesses of 35cm and 100cm, overlying an approximate 5 m thick coke deposit. The two
reclamation soil covers were constructed using peat-mineral mix placed over secondary (glacial
till).
The global objective of this research program was to evaluate the preliminary performance for
each of the soil covers with respect to the available water holding capacity (AWHC). The
specific objectives were to: a) install additional instrumentation to supplement the existing
instrumented watersheds; b) characterize the properties of the covers on each watershed; and c)
develop a preliminary, one-dimensional water balance for each watershed.
Existing instrumentation on each cover (installed by others) included: a meteorological
station; automated soil stations to monitor suction, water content and temperature; and,
lysimeters to collect net percolation. Additional instrumentation was installed during this
research program to track vertical and horizontal variations in soil conditions and included:
access tubes for monitoring water content; temperature sensors; gas sampling points; and,
standpipe piezometers to determine depth to the water table. The instrumentation generally
performed well, with the exception of the lysimeters which did not appear to measure net
percolation accurately. Through the measurement of soil parameters, interpretation of field
monitoring data and laboratory testing, the covers were characterized for their relative ability to
store water for plant growth.
A water balance was determined for each watershed. Evaluation of the covers indicated that
neither the deep nor the shallow covers were successful at storing sufficient water necessary for
plant growth under dry conditions. However, the deep cover performed better than the shallow
cover based on the overall cover performance, likely due to its higher AWHC.
Description
Keywords
oil sands, reclamation: cover trials
Citation
Degree
Master of Science (M.Sc.)
Department
Civil and Geological Engineering
Program
Civil Engineering