The Challenge: Safe release and reintegration of oil sands process-affected water

Open-pit mining of oil sands in Canada's Athabasca region relies on freshwater for the extraction of valuable bitumen. The resulting oil sands process-affected water (OSPW) is toxic, mainly because of bitumen-derived dissolved organic compounds. To date, no releases of treated OSPW to the natural aquatic environment have been approved. As production of bitumen increases, inventories of OSPW will likely grow. Furthermore, tailings pond seepage is now a growing concern and is being intensively studied. Although strategies for remediation of OSPW are under development, there are still no chemical or toxicological guidelines to regulate the safe release or reintegration of OSPW back into the surrounding environment. With so many stakeholders, an open discussion on what to do with this water is needed. Science, policy, and water-management practices are evolving quickly, prompting us to seek informed perspectives on this challenging topic. Jonathan W.