"Well, it looks like what they've seen is that in fact the tailings ponds are leaking," said Bill Donahue, environmental scientist with the oilsands advisory committee. "They found also not only are those tailings ponds leaking, but it looks like it is flowing pretty much from those tailings ponds, through the ground and into the Athabasca River."

The Environment Canada study used new technology to actually fingerprint the mix of groundwater chemicals in the area. It found the mix of chemicals from tailings is different from that in naturally occurring bitumen deposits. That tailings mix, which contains toxic chemicals, is found in groundwater around mining operations, but not in areas away from development. The Pembina Institute, an environmental research group, has long said the ponds leak.

Analyst Erin Flanagan said the new research shows even Pembina underestimated how much. "As we continue to expand the industry, we're also expanding the production of tailings waste."