CALGARY – Environmental groups say the Government of Canada is failing to meet its legal responsibilities by exempting tailings pond chemicals from a recent screening assessment.

In a comment letter sent to Health Canada and Environment and Climate Change Canada on behalf of Environmental Defence and Keepers of the Athabasca on Oct. 17, Ecojustice lawyers called on the government to reconsider naphthenic acids from oil sands process-affected water in assessing whether these chemicals should be regulated under law.

“Canadian environmental laws require screening assessments to consider quantity, concentration and conditions under which a chemical is entering the environment,” Ecojustice lawyer Fraser Thomson said. “Together with our partners, we are asking the government to meet its legal responsibilities by going back, conducting an assessment of naphthenic acids from tailings ponds in the Alberta oil sands and letting the science speak for itself.”

Naphthenic acids are a byproduct of bitumen extraction in oil sands process-affected water, which is stored in tailings ponds. Though naphthenic acids also have a variety of commercial uses, oil sands process-affected water is the main source through which they enter the environment.

Despite this, the federal government refused to consider naphthenic acids from tailings ponds when it conducted a mandatory screening assessment of the chemicals under the Canadian Environmental Protection Act Instead, the government exclusively looked at the less-significant manufacturing sources of naphthenic acids.

“Tailings ponds are huge lakes of toxic chemicals and they’ve been found to leach into groundwater and the Athabasca River. It is alarming that the government avoided any possibility of having to take action to control the impacts of naphthenic acids in tailings ponds by excluding them from its screening and focusing solely on naphthenic acids deliberately manufactured for commercial use,” said Muhannad Malas, toxics program manager at Environmental Defence.

Jule Asterisk, the interim executive director for the Keepers of the Athabasca added:

“The cumulative effects of bitumen production in Alberta currently pose a severe threat to the environment and human health. This is felt most acutely by those living downstream and downwind from the oil sands. By failing to include naphthenic acids from tailings ponds in its assessment, the federal government is failing to account for further risk and liability to these communities.”

When the Minister of Environment and Climate Change and Minister of Health add a substance to the list of chemicals deemed “toxic” under CEPA, it automatically triggers a number of legal obligations to control it. In the case of naphthenic acids, this could mean introducing changes to how these chemicals are managed in tailings ponds.

The screening assessment — which did not consider naphthenic acids in tailings ponds — ultimately found that low levels of exposure to commercial source sources of the chemical pose a low risk to human health and are unlikely to result in concerns for the environment. As a result, the government classified the substances as not “toxic” under CEPA.

This means the government is not currently obligated to take any further steps to control naphthenic acids in tailings ponds.

By contrast, the United States classifies naphthenic acids as a hazardous substance and regulates them under its Clean Water Act.


Ecojustice, Canada’s largest environmental law charity, goes to court to defend nature, combat climate change, and fight for a healthy environment for all.

Environmental Defence ( is Canada’s most effective environmental action organization. We challenge, and inspire change in government, business and people to ensure a greener, healthier and prosperous life for all.

Guided by both indigenous Elders’ Traditional Knowledge and western science, the Keepers of the Athabasca (2006) are First Nations, Métis, Inuit, environmental groups, and citizens working together for the protection of water, land, air, and all living things today and tomorrow in the Athabasca River watershed.  Our mission is to unite the peoples of the Athabasca River Watershed to secure and protect water and watershed lands for ecological, social, cultural and community health and wellbeing.