The development of oil sands reserves in the Fort McMurray region has seen active mining occur over an area ~250 km², this is expected to grow as large as 1400 km² by 2023 (1;2). Extraction processes, refinement and tailings waste have seen resulted in significant disturbance to peatlands on the boreal plain landscape of Alberta. Peatlands comprise up to 65 % of the landscape, with the majority of these identified as fen systems (3). Under the Alberta Environmental Protection & Enhancement Act (AEPEA) (approvals No. 94-02-00) for mine closure approval certificates to be granted, portions of the post-oil sands landscape need to be reclaimed to functioning fen ecosystems and their surrounding watersheds. The Suncor Pilot Fen Project is a research-led constructed fen system that is presently under construction. It is based upon a conceptual hydrological model (4) and several re-vegetation strategies (5;6;7). Construction began in the fall of 2010, with a completion date aimed for April, 2013 (8). The Pilot Fen Project aims to evaluate the success of the design by testing the materials types and their placement used in construction; whether it can deliver water of adequate quality to the constructed fen; methods of re-vegetation; appropriateness of plant and microbial fen species and how all of these contribute to carbon accumulation within the constructed fen.
Fen peatlands rely on ground or surface water inflows to sustain the water balance and modify the water quality (9). It has been suggested that fen creation is feasible (4), and this concept has been adapted into the Alberta Environmental Protection & Enhancement Act (AEPEA) approvals No. 94-02-00, requiring Suncor Energy to test this concept by December 2012. The fundamental problem for fen construction is to design a groundwater system that can support the inflows required to sustain the hydrological, biogeochemical and ecological processes and functions, and minimize the adverse effect of poor water quality derived from tailings sand used in its construction. In such a system, fen peat borrowed from new lease areas being opened for development is to be placed at the base of an aquifer/aquitard system designed to supply the requisite flow (4). The goal is to create a self-sustaining ecosystem that is carbon-accumulating, capable of supporting a representative assemblage of species and resilient to normal periodic stresses. In addition to assisting Suncor Energy comply with its legal obligation to reclaim fens in the post-mined landscape, this research is essential to understanding design implications and to the development of more optimal designs and cost-effective protocols. It will also make a significant contribution to training of HQP and to both applied and fundamental knowledge in fen hydrology, bio-geochemistry and ecology. Fen creation is a new concept, and designing a fen and its watershed is largely untested. Amon et al. (2005)(10) generated fen plants and a thin deposit of organic material on small plots lined with gravel and fed by calcareous artesian water, but field-scale fen construction has not been attempted. Syncrude Canada, Inc. is simultaneously constructing a fen system based on a mix of theoretical and practical ecological and hydrogeological principles, which uses a managed water reservoir to supply flows to a thin (~50 cm) layer of peat covering a constructed valley system. The Suncor Pilot Fen is designed to be self-contained (requiring no managed water supply); Price et al. (2010)(4) used a numerical model of the coupled fen-upland system to provide suggestions regarding the requisite materials based on their hydraulic properties and geometric configuration (e.g. slope, thickness, etc.). The system has been designed with a low permeability “liner” is placed over the target site, with a low gradient slope, tailings sand used to form the aquifer system, overlying the liner. At the lower end of the system, donor peat materials are placed over the sand aquifer to form the fen. The upland area, which contributes groundwater to the fen, is covered with an ‘Lfh’ soil horizon (e.g. boreal forest soils) and re-vegetated primarily with ericaceous shrubs and a sparse cover of native tree species ranging from tamarack and black spruce near the fen, to jack pine at the uppermost part of the upland. Finally, plant species will be introduced to the fen according to a detailed experimental design.
The pilot fen project will allow for evaluation of the success of the design, including:
1) materials type and placement;
2) its ability to deliver water of adequate quality to a built-system;
3) the method of re-vegetation;
4) the appropriate fen plant and microbial species;
5) how these contribute to the accumulation of carbon in the system
In evaluating the success of the design, a number of reference sites to the south and north of the pilot fen project are being assessed to understand what type of ecosystem pilot fen project may develop into, the characteristics of these natural sites and how results seen in the constructed system reflect real, localised fen systems. These sites comprise of an incredibly saline fen, a rich fen known as poplar fen and a fen system known as pauciflora that also features a bog portion within its boundaries.
References: 1Woynillowicz, D., Severson-Baker, C., and Raynolds, M. 2005. Oil Sands Fever: The Environmental Implications of Canada’s Oil Sands Rush. The Pembina Institute, Drayton Valley, Canada; 2Alberta Environment, 1999; 3Vitt, D.H. and Chee. W.-L. 1989. The vegetation, surface water chemistry, and peat chemistry of moderate-rich fens in central Alberta, Canada. Wetlands 9:227–261; 4Price, J.S., McLaren, R.G. and Rudolph, D.L. 2010. Landscape restoration after oil sands mining: conceptual design and hydrological modelling for fen reconstruction. International Journal of Mining, Reclamation and Environment 24:109–123; 5 Rochefort, L., Quinty, F., Campeau, S., Johnson, K.W., and Malterer, T.J. 2003. North American approach to the restoration of Sphagnum dominated peatlands. Wetlands Ecol. Manage. 11:3-20; 6 Cooper, D.J. and MacDonald, L.H. 2000. Restoring the Vegetation of Mined Peatlands in the Southern Rocky Mountains of Colorado, U.S.A. Restoration Ecology, 8: 103-111; 7 Cooper et al., 2007 8 Daly, 2010; 9 Ingram, H.A.P. 1983. Mires: Swamp, Bog, Fen and Moor, In: Gore, A.J.P. Ecosystems of the World. Elsevier, Oxford. 67-158; 10 Amon, J.P., Jacobson, C.S. and Shelley, M.L. 2005. Construction of fens with and without hydric soils. Ecol. Eng. 24, 341–357