Characterization of Key Performance Measures at the Reclaimed Sandhill Wetland: Implications for Achieving Wetland Reclamation Success in the Athabasca Oil Sands.
Hartsock, J. A.. 2020. Southern Illinois University Carbondale
Abstract
Fens and marshes are important landscape features in northern Alberta, Canada that
occupy a significant portion of the Oil Sands Administration Area (OSAA). Disturbance from oil
sands mining activities has affected many wetlands in the region. Because of this disturbance, oil
sands mining companies near Fort McMurray, Alberta (e.g., Syncrude Canada Ltd. and Suncor
Energy) are legally obligated to return previously mined areas to systems that support land uses
equivalent to the pre-disturbance landscape. The experimental Sandhill Watershed is the first
attempt by an oil sands operator (Syncrude Canada Ltd.) to construct a watershed above a
previously mined landscape potentially capable of supporting a peat-forming wetland. Water
samples were collected over a ten-year period (years 2009 - 2019) from near-surface and ground
water sampling locations in the wetland area. Here, I present a history of dissolved ion
concentrations measured at the reclaimed wetland. I also provide a comprehensive synopsis of
dissolved ion concentrations obtained from twelve reference wetlands, as a comparison against
the reclamation site. From the data provided, results indicate that the dominant anions and
cations present in the Sandhill Wetland near-surface water (e.g., bicarbonate, sulfate, chloride,
sodium, calcium, and magnesium) have increased annually since the first full growing season.
Regression analysis shows near-surface sodium and chloride concentrations will reach sub-urface levels in approximately 8 and 7 years, respectively. If these trends manifest, the chemical
conditions at the Sandhill Wetland will be analogous to saline fens in the future. The reclaimed
wetland currently exhibits attributes similar to saline fens and slightly brackish marshes. For race metals, heavy metals, dissolved nitrogen, dissolved phosphorus, and dissolved organics, the
Sandhill Wetland was quite comparable to all the reference wetlands. Of note, naphthenic acid
and polycyclic hydrocarbon concentrations were below detection limits at the reclamation site,
an important discovery as many of these compounds cause problems for insects, amphibians, and
birds at low concentrations. I recommend monitoring of both water chemistry and plant
composition patterns at the Sandhill Wetland should continue to capture important successional
changes that may occur as the site matures.
