A recent string of leaks from tailings ponds at oil sands operations upstream has once again drawn attention to the profound transformation Canada’s largest industry has had on the region – and the distrust that comes with it. In May, Calgary-based Imperial Oil notified Alberta’s energy regulator it had discovered discoloured water near its Kearl oil sands project. The regulator soon concluded the water had come from tailings ponds where the company stored the toxic sludge-like byproducts of bitumen mining. Environmental samples showed high levels of several toxic contaminants, including arsenic, iron, sulphate and hydrocarbon – all of which exceeded provincial guidelines.

Indigenous communities in Canada's oil sands region on Monday called for Alberta's energy regulator to be disbanded and replaced following a months-long toxic tailings seepage from Imperial Oil's Kearl oil sands mine. Community representatives were testifying to a parliamentary committee in Ottawa about the impact of the leak and ongoing concerns about oil sands tailings management.