As production in Alberta's oilsands continues to expand, waste byproducts continue to build up as well, from petcoke piles to tailing ponds. Now the energy companies behind the oilsands boom are planning to dump their growing volumes of toxic wastewater into man-made lakes, in the hope that they eventually become natural habitats.

Jeremy van Loon of Business Week writes that Syncrude Canada, Royal Dutch Shell, and ExxonMobil affiliate Imperial Oil "are running out of room to store the contaminated water that is a byproduct of the process used to turn bitumen–a highly viscous form of petroleum–into diesel and other fuels."

By 2022 the monthly output of wastewater from these companies "could turn New York's Central Park into a toxic reservoir 11 feet deep, according to the Pembina Institute," writes van Loon.

To accommodate the growing volume of byproduct, the energy companies have reportedly "obtained permission from provincial authorities to flood abandoned tar sand mines with a mix of tailings and fresh water." According to van Loon, this would "transform northern Alberta into the largest man-made lake district on earth."

Syncrude's Base Mine Lake, on which work began last summer, will measure 2,000 acres when complete, and is expected by the company to "eventually replicate a natural habitat, complete with fish and waterfowl."

Non-profit environmental group Pembina describes these end pit lakes as "high-risk and experimental," noting that "historical data about using end pit lakes as toxic waste dumps are insufficient to determine whether or not they are a safe, long-term tool for reclaiming tailings waste as no example of a functional end pit lake currently exists."

There are about 30 end pit lakes planned for the Athabasca Boreal region, according to Alberta's Cumulative Environment Management Association.

"There's no way to tell how the ecology of these lakes will evolve over time," said Jennifer Grant, director of oilsands at Pembina. "It's all guesswork at this point. It's reckless."

"We're playing Russian roulette with a big part of an important ecosystem," said David Schindler, an ecology professor at the University of Alberta. "Nothing is going to grow in that soup of toxic elements except perhaps a few hydrosulfide bacteria. And all of the unforeseen events are being downplayed."

Syncrude began creating an end pit lake 30 miles north of Fort McMurray this summer, filling in a mine with fresh water from a dam to a depth of 16 feet to keep toxic tailings down at the bottom. According to company spokeswoman Cheryl Robb, trials involving "test ponds" resulted in naturally occurring ecosystems, with microbes helping to break down pollutants.

However, van Loon writes that the "largest test pond was 4 hectares–roughly 1/200th the size of Syncrude's lake."

"The big question we have is how long will it take before the water is clean, how long is it going to take before the littoral zones develop and the shoreline vegetation builds up?" said Robb. "But we're confident in the technology."

One of the major concerns surrounding end pit lakes is the possibility of contaminated water seeping into the boreal ecosystem. In October, "communities bordering Canada's Athabasca River were cautioned not to drink from the waterway after a breach in a coal tailings storage pond dumped 1 billion liters (264 million gallons) of contaminated water into an area west of Edmonton."

According to Pembina, the exact amount of seepage from tailings in Alberta is "either not known or has not been made public," but modelled estimates suggest that "11 to 12.6 million litres of tailings leak from tailings ponds each day."

Image Credit: WhitneyH / Flickr

Another year of keeping a close watch
Here at The Narwhal, we don’t use profit, awards or pageviews to measure success. The thing that matters most is real-world impact — evidence that our reporting influenced citizens to hold power to account and pushed policymakers to do better.

And in 2024, our stories were raised in parliaments across the country and cited by citizens in their petitions and letters to politicians.

In Alberta, our reporting revealed Premier Danielle Smith made false statements about the controversial renewables pause. In Manitoba, we proved that officials failed to formally inspect a leaky pipeline for years. And our investigations on a leaked recording of TC Energy executives were called “the most important Canadian political story of the year.”

As the year draws to a close, we’d like to thank you for paying attention. And if you’re able to donate anything at all to help us keep doing this work in 2025 — which will bring a whole lot we can’t predict — thank you so very much.

Will you help us hold the powerful accountable in the year to come by giving what you can today?
Another year of keeping a close watch
Here at The Narwhal, we don’t use profit, awards or pageviews to measure success. The thing that matters most is real-world impact — evidence that our reporting influenced citizens to hold power to account and pushed policymakers to do better.

And in 2024, our stories were raised in parliaments across the country and cited by citizens in their petitions and letters to politicians.

In Alberta, our reporting revealed Premier Danielle Smith made false statements about the controversial renewables pause. In Manitoba, we proved that officials failed to formally inspect a leaky pipeline for years. And our investigations on a leaked recording of TC Energy executives were called “the most important Canadian political story of the year.”

As the year draws to a close, we’d like to thank you for paying attention. And if you’re able to donate anything at all to help us keep doing this work in 2025 — which will bring a whole lot we can’t predict — thank you so very much.

Will you help us hold the powerful accountable in the year to come by giving what you can today?

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