An oil sands extraction facility is reflected in a tailings pond near the city of Fort McMurray, Alta., on June 1, 2014. An international environmental watchdog says there's convincing evidence that oilsands tailings ponds are leaking. But after three years of investigation, a body set up under the North American free trade agreement can't tell if the federal government is enforcing its own laws forbidding such releases. THE CANADIAN PRESS/Jason Franson