Scientists find microplastics in Edmonton’s sole source of drinking water

Tiny fibres and fragments of plastic have been detected in the North Saskatchewan River in Edmonton, offering yet more evidence of the pervasive nature of plastic pollution.

In a study published Jan. 14 in the journal Facets, researchers from MacEwan University detailed the results of water sampling conducted at eight sites along a roughly 66-kilometre stretch of river during the summer of 2017. Microplastics were detected in all 22 water samples the team collected.

“It was not unexpected to find this level of microplastics in the river,” Matthew Ross, an assistant professor of environmental chemistry at MacEwan University and one of the study’s authors, told The Narwhal. “We’ve been able to find microplastics in pretty much anything scientists have looked at.”

Scientists have found microplastics near Everest’s peak and along the ocean floor, in oysters, Arctic belugas and even in the air. 

As the world struggles to tackle the problem of plastic pollution, Jason Kenney’s United Conservative Party government is banking on a growing plastics and petrochemical industry to help diversify Alberta’s economy.

While the province has committed to building Alberta into a world leader for plastics recycling, companies are planning manufacturing complexes that will pump out new plastic products as well, including a major new facility along the North Saskatchewan River. 

More research needed to fully understand microplastic risk

The levels of microplastics detected in the North Saskatchewan River were “low enough that [they’re] likely not causing a big risk to wildlife,” Ross said. 

He cautioned that his answer might change as concentrations of microplastics increase and as scientists gain a deeper understanding of the potential risks microplastics may pose.

“If we don’t mitigate this, presumably, we’ll see increasing concentrations,” he said.

While there are still unknowns about the full impact of microplastic pollution, these tiny particles may cause tearing or blockages in the digestive tracts of organisms that eat them, according to the Facets article.

“Microplastics may also act as a vector for the transport and release of organic contaminants, such as pesticides, plasticizers, flame retardants and additives to organisms once ingested,” the researchers note in the study.

While most microplastic research has so far focused on oceans, studies have found similar and, in some cases, greater levels of microplastic pollution in lakes and rivers, according to the Facets study. 

Study is first to measure microplastics in western Canadian river

In Canada, there have been only a handful of studies focused on microplastics in fresh water. This was the first to examine microplastic pollution in a river in western Canada as far as the authors are aware.

As the North Saskatchewan River winds its way east from the glaciers of the Rocky Mountains, it crosses an area known as Alberta’s industrial heartland, before moving into Saskatchewan and eventually Manitoba, where it empties into Lake Winnipeg.

Over the years, the waterway has faced increasing pressure from the energy industry with new pipeline crossings and spills.

The North Saskatchewan River traverses a large region stretching from Alberta, including the Kootenay Plains in Bighorn Wildlands Area shown here, to Manitoba. Photo: Darwin Wigget

In December, contaminated water spilled from a pipeline in the Drayton Valley into a creek before flowing into the river. Farther downstream, a major pipeline spill in 2016 forced a number of communities in Saskatchewan to stop drawing water from the river for two months. 

Edmonton, with a population nearing a million, is the largest city within the North Saskatchewan’s watershed.

Of the eight sampling sites, one was upstream of Edmonton, six were within city limits and one was downstream.

The authors said the microplastic concentrations detected in the North Saskatchewan were consistent with those found in other North American rivers, but cautioned direct comparisons are challenging due to differences in the way samples were collected and analyzed. 

Due to the size of the mesh the team used to collect their samples, the smallest microplastics they were able to detect in the North Saskatchewan River were 53 microns — about a third of the size of grain of sugar. Microplastics are typically defined as pieces smaller than five millimetres. 

Most of the microplastics detected in the river were human-made fibres, either polyester or cotton. Of the fragments they detected, most were identified as polyethylene or polypropylene.

Drinking water utility says microplastics not a safety concern

While the North Saskatchewan River is Edmonton’s sole drinking water source, EPCOR, the city’s drinking water provider, said the presence of microplastics in the river is not a concern for the utility’s ability to provide safe drinking water.

“Our water treatment plants are capable of screening out very small particles, like bacteria,” a spokesperson said in a statement emailed to The Narwhal, explaining that “generally microbeads [a type of microplastic] are larger than the bacteria we treat in the water every day.”

Ross said the smallest microplastics his team detected — about 0.053 millimetres in size — are close in size to the largest bacteria.

“Presumably, if they can filter out much smaller bacteria, they’ll also remove microplastics and other particulates in this size range,” he said.

While EPCOR does not and is not required to test for microplastics, the utility “closely monitors the research and new developments on this subject,” the statement said.

Stormwater drains likely flushing microplastics into river

The researchers sampled both upstream and downstream of a wastewater treatment plant outfall, but noted there was no uptick in microplastics immediately downstream of the plant. 

“It suggests to us that the sources are more diffuse,” Ross said.

Microplastics could be washed into the river through storm drains, or fibres that shed from clothes could be carried through the air, he explained.

Ross noted that his team has detected high concentrations of microplastics in samples collected from stormwater drains in Calgary as part of new research. They’re also starting to look at concentrations in stormwater retention ponds in the Edmonton area.

The North Saskatchewan River, which runs through Edmonton, is the city’s sole source of drinking water. However, the city’s drinking water provider said the presence of microplastics is not a concern. Photo: Kurt Mauschardt / Flickr

Biosolids collected from wastewater treatment plants and used as fertilizers could be another source of microplastics, the Facets paper notes.

Ultimately, Ross said, cutting down the amount of plastic we use is a key to stemming the flow of microplastic pollution.

“Some of this plastic is likely coming from the degradation of litter and then the eventual runoff of that into the river,” he said. “So simply reducing the amount of plastic that we’re using would hopefully help stem some of that source.”

Industry, researchers partner on new microplastics research on North Saskatchewan River

Microplastic research will continue along the North Saskatchewan River over the next few years. 

In addition to Ross’s work, a multi-year study is underway by researchers at the Northern Alberta Institute of Technology (NAIT), supported by $10 million in funding from Inter Pipeline, an energy infrastructure company that’s building a new petrochemical complex along the North Saskatchewan River to manufacture polypropylene plastic.

The researchers are working to develop methods to identify and measure microplastics in both freshwater and river sediments. The researchers have already collected more than 140 water and sediment samples.

Federal government, Alberta at odds over path forward on plastics

The federal government has said it wants to cut plastic waste to zero by 2030 and has proposed a ban on certain single-use plastic items, including straws, stir sticks, cutlery and six-pack rings. 

The government has also proposed new requirements for recycled content in products and packaging, a measure aimed at extending the life of plastics, and new regulations are expected to be finalized by the end of this year.

In Alberta, meanwhile, Premier Kenney has said plastics are “a real ace in the hole for Alberta’s future.”

Kenney took issue with the federal government’s plans to label plastic items as toxic under the Canadian Environmental Protection Act, calling the label “unscientific” and suggesting it would hurt Alberta’s economic recovery.

Alberta Minister of Energy Sonya Savage was also not impressed with the federal plan, saying “plastics are the foundation of the modern world.” 

Federal Minister of Environment and Climate Change Canada Jonathan Wilkinson has said the designation shouldn’t affect the province’s efforts to increase plastic recycling and has noted that every year “29,000 tonnes of plastic waste enters into and pollutes our natural environment.”