The results of this study highlight the potential environmental damage that will occur if OSPW is not carefully managed. In the mesocosm study, even a 90% dilution of the OSPW mixture was not sufficient to protect sensitive macroinvertebrate communities. In the 72-h test, no mayflies survived treatment levels greater than 0.5 mg sodium naphthenate/l. We found that safe concentrations for mayflies and other aquatic macroinvertebrates were less than 1 mg/l, as no mayfly taxa survived repeated exposure to this dose in either the 48-h or 72-h acute toxicity test. We assess the effects of these simplified oil sands process water (OSPW) mixtures under planned and unplanned tailings release scenarios, using traditional and cutting-edge bioindicators for aquatic invertebrate taxa. This study examines the acute toxicity of environmentally relevant 10:1 mixtures of two process water components: naphthenic acid and sodium naphthenate. Of particular concern are naphthenic acids and their metallic counterparts, as they are the principal toxic components of tailings, are relatively soluble, and are persistent in aquatic environments. This represents an environmental management challenge, as the tailings contain contaminants that are known toxins to aquatic communities. Due to limited storage capacity, the planned release of tailings into the surrounding environment may be required. Extraction of Canada’s oil sands has created 1 billion m 3 of tailings, which are stored in on-site tailings ponds.

Eco global survival alpha 5.6 tailings