CT Tailings Integrated Reclamation Landscape Demonstration

Suncor had been using Consolidated Tailings (CT) as the basis for tailings management prior to 2009. Past mine pits were backfilled with CT material then reclaimed as terrestrial and wetland landscapes. Since 2009, Suncor has used Tailings Reduction Operations (TRO) to manage tailings, but there are still legacy CT in mining areas that require reclamation, so there remains a need to understand potential impacts of CT on the environment. In particular, the presence of sodium chloride, sodium sulphate salts, naphthenic acids and residual hydrocarbons present reclamation challenges. The 34 ha study site was created in 1999-2000 to assess approaches for reclaiming a CT landscape. The multi-year CT Demo project focuses on water balance, water and sediment quality, wetlands vegetation and terrestrial vegetation. The focus of Phase I (2000 to 2004) in the CT Demo site was to assess wetlands and terrestrial vegetation that were planted or naturally colonized the site. Phase I of the project was completed in 2004 and consisted of water balance determination, detailed vegetation monitoring, and water and sediment chemical analyses in the aquatic and terrestrial landforms. Phase II began in 2005 and consists mainly of water quality and vegetation monitoring, increasing ground cover and diversity in wetland and riparian areas and assessing bioaccumulation in plant tissue.

The final report from 2010 summarizes results from the 6th year of Phase II and the 11th year of monitoring. Vegetation appears to be establishing successfully. 97 species have naturally established or been transplanted in. Average ground cover is 65%, with areas that have not flooded having higher cover. Comparable conditions could be expected on similar reclamation areas, assuming similar capping soil and water constraints. 33 species have been identified as good candidates for capped CT reclamation sites, and 5 as good candidates for uncapped CT reclamation sites. The use of plug plots, especially those from saline donor sites, appears especially successful for increasing diversity in the study area.