Environmental watchdog report says Alberta oilsands tailings ponds are tainting groundwater

A North American environmental watchdog found there is “scientifically valid evidence” that oilsands tailings ponds are contaminating groundwater sources.

Alberta's chief scientist says he is reviewing the report

Oil flows into a tailings pond at the Suncor oilsands operations near Fort McMurray, Alberta, on September 17, 2014. (Todd Korol/Reuters)

An environmental watchdog says it has found "scientifically valid evidence" that Alberta's oilsands tailings ponds are contaminating groundwater sources.

The report was released Thursday by the Commission for Environmental Cooperation, an independent international organization tasked with implementing an environmental side accord to the North American free-trade pact.

"Based on the scientific tools used today, the current literature shows that there is strong scientifically valid evidence of oilsands processed water seepage into near-field groundwater around tailings ponds when compared with the first peer-reviewed evidence published in 2009," says the report.

Tailings ponds, such as the ones used by oilsands mining operations north of Fort McMurray, Alta., collect by-products from oilsands mining operations — a mixture of water, sand, residual bitumen and other hydrocarbons that the industry calls "processed" water.

Many of these by products are toxic and environmentalists have long warned of the risks of leaks from tailings ponds, while the residual oil that covers the ponds can trap migratory birds.

These massive ponds are bordered by outer walls of dirt built to hold back the tailings water — which, as the report notes, "is an acutely toxic substance containing, among other things, naphthenic acids and heavy metals."

For years it's been unclear whether pollutants detected in waterways near oilsands operations came directly from plant operations or from bitumen already in the soil.

WATCH: Environment Minister wants to see a solution to Canada's tailings pond problem

'We need to find solutions' to the tailings pond problem

3 years ago
Duration 0:58
Environment and Climate Change Canada Minister Jonathan Wilkinson says solutions need to be found to address the problem of tailings ponds.

Although tailings ponds may be leaking into groundwater, the commission found there is less evidence to suggest it's seeping into surface water sources like the Athabasca River, which runs adjacent to one of the oldest oilsands tailings ponds.

"The literature shows that there is no evidence of dissolved bitumen-derived organics (natural or anthropogenic) being detectable in any water samples, although a major challenge to spotting any seepage is dilution in a very large river," the report states.

'Canada needs to take greater action': First Nation

The Commission for Environmental Cooperation launched its probe of tailings ponds after environmental groups — including Environmental Defence Canada — filed a submission in 2017 that accused the federal government of failing to enforce the federal Fisheries Act by not prosecuting oilsands producers over the "alleged leaking of deleterious substances." 

The Commission for Environmental Cooperation cannot issue binding rulings. Rather, it reports its findings.

"To me, the evidence is really clear," said Dale Marshall, a program manager for Environment Defence. "It tells us that the federal government is not upholding its responsibility to protect human health and the environment."

One of the First Nations communities downstream from the oilsands operations, the Mikisew Cree First Nation, has for years raised alarm bells about leaking tailings ponds. Melody Lepine, a band member and director of the nation's government and industry relations arm, is calling on the government to act and enforce its regulations. 

"We cannot accept that these tailings ponds pose no risk and it's business as usual," Lepine said. "Canada needs to take greater action." 

Alberta government reviewing report

The Alberta government's chief scientist, Garry Scrimgeour, said he's still reviewing the report, noting it was just released and the government will "need to take the time to review it."

But Scrimgeour said the latest science he's familiar with is not conclusive whether it's possible to distinguish between oilsands contaminants and chemicals naturally occurring in groundwater.

He also noted the oilsands industry and government had made significant strides to rehabilitate and reduce tailings ponds with new technology.

Environment and Climate Change Canada Minister Jonathan Wilkinson expressed his concern about the independent commission's findings.

"The conclusions of the report are very troubling, and certainly they cannot be ignored," Wilkinson said. "The oilsands tailing issue is a problem that we are going to have to address going forward."

An official with Environment and Climate Change's enforcement branch said federal testing has resumed after a pause in 2014 to better understand the difference between water that's been affected by oilsands operations and water that has naturally occurring chemicals.

"Whenever harmful substances were found, it was impossible for us with the science and technology available at that time to distinguish substances coming from processed water to those that may be naturally occurring in the groundwater," Daniel Smith, a regional director for the department's enforcement, told CBC.

In 2019, Smith said, the department resumed its inspections and is applying the recent advances in science to the samples it collected last year. These samples, Smith said, are still being assessed, and no-conclusion has been reached about whether the department will be laying charges.

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David Thurton

Senior reporter, Parliamentary Correspondent

David Thurton is a senior reporter in CBC's Parliamentary Bureau. He covers daily politics in the nation’s capital and specializes in environment and energy policy. Born in Canada but raised in Trinidad and Tobago, he’s moved around more times than he can count. He’s worked for CBC in several provinces and territories, including Alberta and the Northwest Territories. He can be reached at david.thurton@cbc.ca

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