Meike Lemmer
Ph.D. student
Department of Phytology
Laval University

Supervised by:

Line Rochefort (Regular member)

Co-supervised by:

Maria Strack (External collaborator)

Research project description

Assessment of reclamation criteria for in-situ well pads in Northern Alberta

Vast areas in the Oil Sands regions of Northern Alberta are used for in-situ bitumen extraction in deep layers of the boreal peatlands. About 895 km2 are estimated as disturbed oil sands surface area. Together with the oil and gas companies, the Government of Alberta is working to establishing successful reclamation criteria for the effective restoration of these peatlands. In-situ recovery methods are necessary to extract the fossil resources, which are located at great depths that preclude the use of open mining methods in these oil sands regions. Mining platforms of circa 1 ha are installed within diverse peatland complexes. In areas with a shallow peat surface layer (less than 40 cm organic peat), the surface peat layer will be extracted before the well pad, a several-centimeters-thick clay fill, is installed. In areas with more than 40 cm organic peat, trees and shrubs will be mulched, to create an even surface area, which will be covered with a geotextile liner and a clay fill of approximately 1.5 m. A berm and dyke drainage system ensures the well pad’s stability and functionality during the oil extraction period. The successful ecological reclamations of these disturbed areas are to be ensured by the mining operators after mining activities have ended. The reclamation process of these disturbed peatlands in boreal Alberta is fairly new. A first successful restoration of a well pad in the Athabasca Oil Sands was undertaken in 2008. Successful reclamation results in the restored peatland acting as a self-sustaining ecosystem. The regulations and criteria for successful restoration are currently being developed and tested. In collaboration with the Boreal Research Institute in Peace River, a research center of the Northern Alberta Institute of Technology (NAIT), this PhD project aims to 1) functionally evaluate the success of restoring the ecosystem and 2) to assess the efficiency of provincial governmental criteria as proxy for the recovery of peatland functions. The project will be carried out in the context of removal of the fill used to construct oil sands well pads in the boreal region of Northern Alberta. To evaluate the effect of pad removal on the peatland ecosystems, two study sites were selected in the Peace River Oil Sands (CNRL Peace River) and in the Cold Lake Oil Sands (Imperial Oil Cold Lake). The well pad “H38” in Cold Lake, AB, is located in a shrubby and treed rich fen complex with deep peat layers of over 40 cm organic peat. Different restoration treatments were tested on this pad: In one section the clay fill and underlying geotextile were completely removed, in another section the clay pad was only partly removed, with the clay layer and geotextile remaining on top of the peat. In both sections, sedge vegetation was introduced in the year following the restoration preparations with the clay removal. The well pad “Skeg No. 12” in Peace River, AB, is located in a treed bog complex. This well pad was never used for any bitumen extraction. The clay pad is still present, only a strip of 30 m width was partly removed and used for vegetation planting experiments undertaken by Southern Illinois University in 2007. The part, with introduced vegetation on the clay fill, now serves as the research section for this PhD project. The vegetation introduced includes several Willow species (Salix sp.), Black Spruce (Picea mariana), Tamarack (Larix laricina), and a range of graminoid species, such as sedges (Carex sp.). The research undertaken for this PhD project focuses on different peatland ecosystem functions. In each treatment section of the two sites, as well as in the adjacent natural peatlands, the following research is conducted: Measuring greenhouse gases, including carbon dioxide (CO2) and methane (CH4) fluxes; vegetation surveys, including all vascular plants and bryophytes; evaluating decomposition and productivity rates of the vegetation; examining water and peat chemistry. This research will improve the understanding of processes involved in peatland restoration after in-situ mining activities and will help to amend the reclamation criteria for the Alberta Oil Sands regions.

Research Site Coordinates

Scientific Communications

Lemmer, M., Xu, B., Strack, M., Rochefort, L., 2022. Reestablishment of peatland vegetation following surface leveling of decommissioned in situ oil mining infrastructures. <strong>Restoration Ecology</strong>(published online 2022-04-28), e13714. DOI: <a href="" target="_blank">10.1111/rec.13714</a>.

Lemmer, M., Rochefort, L., Strack, M., 2020. Greenhouse gas emissions dynamics in restored fens after <em>in-situ</em> oil sands well pad disturbances of Canadian boreal peatlands. <strong>Frontiers in Earth Science</strong>, 8, 557943. DOI: <a href="" target="_blank">10.3389/feart.2020.557943</a>.

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