An investigation was launched this week after a series of leaks in Alberta’s oilsands went unreported for months. Industrial wastewater containing dangerous levels of arsenic and other chemicals is stored in about 30 reservoirs across the region known as tailings ponds – with an estimated footprint of 300 square kilometres. The leak, which took place at the Kearl Lake site operated by Imperial Oil, is now under investigation by Alberta’s privacy watchdog and has raised serious questions about all tailings ponds. Heather Yourex-West reports.