What are the risks to the NWT’s water quality?

This is the second of two articles on the relationship between water in Alberta and water in the Northwest Territories. This article focuses on water quality – including how industrial activity in Alberta can impact communities downstream.

Industrial contaminants, tailings ponds management, transboundary governance and water monitoring all play a role in Alberta’s water quality – and the water that flows to the Northwest Territories.

Here, we take a look at some of the biggest issues around the quality of water in the NWT.

Treat and release

The oil sands industry is a major water user in Alberta and the toxic liquid waste (or tailings) from mining extraction is held in tailings ponds.

The ponds allow solids – including sand, silt, naphthenic acids and bitumen residue – to settle, and the water can then be recycled for further use in mining. 

Currently, Alberta’s tailings ponds hold more than 1.4 billion cubic metres of fluid and cover an estimated area of more than 300 square kilometres.

Following recommendations from the Government of Alberta’s Oil Sands Mine Water Steering Committee in 2025, the province is creating an accelerated plan to return the water in tailings ponds to the water cycle.

That includes finding new technologies to treat tailings and establishing standards for releasing treated mine water back into the watershed – a process known as “treat and release.”

But critics are skeptical that treat and release will result in safe water.

“We’re really concerned about the potential of treating and releasing tailings into the Athabasca River, or any river in the oil sands region,” said Pamela Narváez-Torres, a conservation specialist at the Alberta Wilderness Association.

“Right now, the government hasn’t been able to provide us with any evidence that the releasing they could be doing into the river is actually safe.”

What reaches the NWT?

Mandy Olsgard is an independent toxicologist and health risk assessor who focuses on contaminants, including how chemicals can be transported through the environment, and potential health effects in exposed populations.

Though oil sands mining companies aren’t currently releasing treated tailings water, they are releasing industrial wastewater and industrial runoff. Additionally, tailings ponds leak, Olsgard said, which can contaminate groundwater.

A 2020 report by the Commission for Environmental Cooperation – a North American intergovernmental group – notes that tailings ponds are often unlined and made from permeable earth, allowing contaminated substances to leak into the environment.

“Companies attempt to recapture the leakage, but do not recapture it all,” the report states. “There are documented cases of contaminated tailings substances reaching or projected to reach surface waters,” including the Athabasca River. 

Indigenous communities in Alberta have long been vocal that they believe water affected by oil sands is a leading cause of high cancer rates in their communities. 

In 2014, a report led by researchers at the University of Manitoba in collaboration with Athabasca Chipewyan First Nation and Mikisew Cree First Nation found that oil sands pollutants were making their way into First Nations’ traditional food sources in northern Alberta. The authors said they had found a correlation between consuming these foods and cancer rates in those communities. 

In a November 2025 press release, the Mikisew Cree Nation said the community was “going through a cancer crisis, with higher than average rates of cancer and rare cancers.”

“Almost every member of Mikisew Cree First Nation has been touched by cancer in some way,” the First Nation wrote.

Observational data from communities in the oil sands regions includes possible cancerous lesions in wildlife and fish, Olsgard said. She says these concerns are a gap in knowledge that needs more study, but added: “It’s not illogical to think that there could be cancer-causing chemicals increasing in water near oil sands mines. We know there’s cancerous chemicals – polycyclic aromatic hydrocarbons, arsenic – these are released.”

However, Olsgard said the risk to water in the Northwest Territories from the oil sands is currently low. 

“Right now, oil sands are contributing to the lower Athabasca River, Lake Athabasca, the Athabasca River Delta, and local creeks and water bodies, and that is a risk for those populations,” Olsgard said.

But for chemicals to be transported farther downstream would require mass loadings, she said. “They do become dispersed and deposited before they reach the Northwest Territories.”

Large amounts of treated water being released from tailings ponds – the change that Alberta is contemplating – would carry a different risk. 

There are gaps in the standards for releasing treated oil sands mine water, said Olsgard.

Oil sands companies rely on two sets of criteria: the Lower Athabasca Regional Plan Surface Water Quality Management triggers – also known as LARP triggers, which were established far downstream of the oil sands – and the Alberta Surface Waters quality guidelines.

Olsgard and aquatic ecologist Dr Megan Thompson researched whether these two sets of guidelines would reliably protect the environment and found some “really substantial gaps and limitations,” Olsgard said.

The LARP triggers are much higher than the concentrations that likely occur naturally in the environment and were established after oil sands mining began. The Alberta surface water quality guidelines, meanwhile, don’t consider human health or consumption of drinking water – they’re focused on aquatic life. “Humans are more sensitive to many chemicals, especially ones that are cancer-causing,” Olsgard said.

People from Indigenous communities may also drink untreated, natural surface water when they’re in the bush and doing land-based activities, she said. 

“So that, to me, has been one of the greatest limitations … You could have potential risk to humans if you rely on the guidelines that industry operators and government are relying on.” 

Olsgard and Thompson published a report in 2023 establishing their own risk-based criteria – designed to replace or expand Alberta’s surface water quality criteria – that consider how people interact with water, specifically First Nation communities in the area. If water was treated and chemicals removed to the levels they proposed, it would likely be safe to release, she said.

But Olsgard said there’s no indication the Government of Alberta will adopt those criteria.

‘This is water we live on’

Finding an alternative to treat and release is an urgent matter, said Jesse Cardinal, executive director of Keepers of the Water, an Indigenous-led water protection group focused on Alberta and the NWT.

“The communities want the tailings ponds off the landscape. They wanted them treated properly and taken care of,” Cardinal said.

“What they are presenting to the communities right now is the cheapest, easiest option for them.

“They’re claiming that they can get all of the harmful chemicals out of what used to be water, and they’re just going to dump it into the river.”

Companies have a legal obligation to clean up tailings within 10 years of mine closure. But Cardinal said companies are being supported by the Alberta government to provide an option that communities don’t want, and that will devastate the watershed – with impacts on water quality, water temperature, fish, and reproduction across species.

Cardinal also notes that treat and release technology is in an early stage and long-term studies haven’t been carried out. “There are definitely no human health studies,” she said.

Keepers of the Water is suggesting a closed loop system, where oil sands companies stop drawing fresh water from the Athabasca River and exclusively use recycled water. The group is co-hosting a water conference in March with Mikisew Cree First Nation, aimed at raising education about treat and release.

“The companies now are at the point where they just want to start dumping the tailings ponds. It’s not OK,” Cardinal said.

“Oil and gas is king in Alberta,” said water advocate Gerry Cheezie. Whatever those industries want, they get, he asserted, regardless of the damage to the environment, people and communities.

Under Treaty 8, “we are supposed to be able to hunt and fish and trap and follow our mode of life forever,” Cheezie said.

“That has changed. We’ve been advocating through the Dene Nation and Treaty 8 Alberta to try to get industry and government to abide by its environmental regulations to no avail … that work is still continuing.”

Dana Fergusson, mayor of Fort Smith, said she doesn’t believe the federal government will allow treated water from tailings ponds to be released.  

“This is water that we live on, we fish on, we swim on, we paddle on,” she said. Impacts from treat and release would “change our way of life here and have some pretty serious consequences.”

Oil sands production is expected to increase in the next several years, and the Government of Alberta is proposing a new pipeline, the Northwest Coast Oil Pipeline, between Alberta and the BC coast. According to the project’s webpage, “demand for oil and gas will remain strong for decades … Alberta is ready to deliver reliable, responsibly produced energy for years to come.” 

The Government of Alberta did not respond to a request for comment. Oil sands companies Suncor and Canadian Natural Resources (CNRL), who have tailings ponds in northern Alberta, did not respond to requests for comment.

A representative from Imperial Oil, asked about management of tailings ponds, treat and release and long-term management strategies, replied via email, “This is good timing, but you have to wait a couple weeks… Something interesting coming out.” They did not elaborate.

Peace River projects

A proposal for a nuclear power project on the Peace River is in its early stages, led by a company called Energy Alberta.

Cheezie has concerns about the project. “We’re against it because most of our communities are downstream, and once this is put into place we will live in the shadow of a nuclear accident happening,” he said. “If they want to build a nuclear reactor, build it beside Calgary, not in northern Alberta.”

In response to questions about possible impacts of the project on water quality, Energy Alberta directed Cabin Radio to a fact sheet on its website with “more information about how water is used in a nuclear facility and our commitment to minimizing impacts.” 

Woodland Cree First Nation is also leading a proposal for a data centre located about 40 km northeast of Peace River. Though in its early stages, an initial report suggests the project and infrastructure could change surface water quality and quantity, with an initial daily water usage of up to 5,000 cubic metres.

Cheezie said he also opposes the data centre’s construction, adding: “Water is very strained at this time.”   

Water governance

In 2023, a massive spill and tailings leak at the Kearl oil sands mine in northern Alberta caused disputes over water quality monitoring and information sharing between the Government of Alberta and the Government of the Northwest Territories.

Since then, representatives from both governments have said there’s better communication between them.

“There’s always ways that we’re working on improving, but there’s definitely been a lot of progress,” said Meghan Beveridge, director of water monitoring and stewardship at the NWT’s Department of Environment and Climate Change. 

One way they’re looking to improve, for example, is ensuring the expectation is outlined for sharing information around proposed developments and activities. 

While Beveridge said the governments aren’t looking to change the transboundary water agreement between the NWT and Alberta, the agreement itself leaves a lot of room to adjust for decision-making or monitoring changes. 

Water monitoring

For decades, periodic environmental assessments have reiterated the need for a long-term monitoring program across the Peace-Athabasca Delta’s aquatic ecosystems. 

Biology professor Roland Hall describes the delta as a key point for water that continues on into the Northwest Territories.

A 2026 report by University of Waterloo researchers Laura Neary, Brent Wolfe and Hall noted that while separate monitoring projects exist, there’s still no delta-wide lake monitoring program “even as concern has grown over the potential for aquatic ecosystem degradation by hydroelectricity dams on the Peace River, oil sands development along the Athabasca River, and climate change.” 

Recently, the Waterloo team finished a seven-year research project to try to come up with a monitoring plan – and a baseline of data for a suite of metals and organic compounds that pose risks to life.

They hope their work can reach a broad audience, including decision-makers at the GNWT, industries, provincial and federal agencies, Indigenous nations and Unesco, and better inform upstream land and water use management decisions through a collaborative approach.

People “would want that kind of information to understand the risks that might be going on further into the Northwest Territories,” Hall said.

Determining risk

Olsgard emphasizes that provincial and territorial boundaries do not define the way water moves. 

“You have to have a higher legislative or regulatory body that’s looking at these transboundary issues to make sure all downstream users and water bodies are protected,” she said.

More: The links between Alberta water decisions and NWT water levels

She can hypothesize that you’d need a mass load of chemicals for them to move into the Northwest Territories. But someone needs to be directing the work of creating predictive modelling to actually evaluate the risk, she said.

“I think that’s been the limitation, because Alberta is really controlling the studies done around oil sands mining.”

She hopes people push for these studies to support risk-based decision-making around potential treat and release from the oil sands mines. 

“The Northwest Territories and those downstream water bodies can’t be disregarded,” she said. “You can’t just assume they’ll be protected.”