Suncor Inc., (Suncor) extracts oil from the Athabasca oil sands (Alberta, Canada). This extraction forms acutely toxic tailings that are stored in dikes. Dike seepage allowed wetland plants to colonize, and Suncor constructed wetlands to assess the potential for bioremediating its effluent with a hummock-wetland system.

The purpose of this study was to determine the physiological effects of oil sands effluent on plant species. The objectives were: (1) to survey and compare off-site and on-site wetland vegetation, (2) to determine effluent effects on growth and apparent photosynthesis (APS) of acclimated ( a ) and non-acclimated (n ) cattail, (3) to test effluent effects on seed germination, and (4) to identify changes in protein synthesis of acclimated and non-acclimated plants exposed to the effluent. Five treatments were studied: (1) N --effluent seeping from dikes, (2) CT --effluent treated with gypsum, (3) DD --effluent polished with phosphorus, (4) C --on-site wetland water, and (5) R --off-site wetland water. The N and CT treatments contain high levels of naturally occurring naphthenic acids (NA) and sulphate.