A mixture of crude gas found in Alberta groundwater

A compound used to clean up acid gas has been found in groundwater in prairies linked to livestock fertility problems, according to a new study.

Scientists from the University of Guelph and the University of Saskatchewan have identified “huge pollutant plumes” of sulfolane, particularly in Alberta.

Dr. Erica Pensini, an associate professor in Guelph's School of Engineering, says researchers are tracking how it spreads in groundwater, work that could help identify threats to the drinking water supply.

He said the research shows that naturally occurring sulfates (salts) interact with sulfolane in groundwater and its ability to “mix better with water.”

“Sulfolane plumes travel faster with less sulfate, so we're trying to explain the migration in the context of what we can do to combat this pollution,” Pensini said in a press release.

“We are also partnering with hydrogeologists and eco-toxicologists to study other aspects that are not directly studied in our lab,” Pensini said.

What is Sulfolane?

Introduced to the market in 1944 by Shell Oil, sulfolane was “widely used” to remove hydrogen sulfide from sour gas – a process known as “sweetening” – at thousands of sites in Alberta.

Sulfolane is practically invisible and does not have a particularly strong smell, so it cannot be detected in water bodies.

“Most of the time, you don't even notice it's there,” Pensini said in a statement to CTV News.

According to a 2008 report by WorleyParsons Komex to Shell Energy Canada, sulfolane was first detected in groundwater in the 1980s and a monitoring program was implemented in 1994.

A regional sulfolane monitoring program that began in 1998 detected sulfolane in groundwater near Shell's Waterton facility.

By 2007, Shell was actively working to phase out sulfolane, building on a pilot project conducted in 2003 and 2004.

Still, Pensini says the chemical's toxicity hasn't been fully determined, and that's why it wasn't properly disposed of.

“That's why crude gas and crude oil refineries released it into aquifers. “According to official sources, there were 5,250 factories (in Alberta) in 2007,” he said.

“Each of these factories could have produced different amounts.”

According to the Canadian government, “the toxicological database for sulfolane is limited.”

“In general, oral exposure to sulfolane in experimental animals has been associated with immunological, renal, and reproductive and developmental effects,” the government website states.

Health Canada states that this compound is unlikely to accumulate in the human body, but should not consume more than 0.3 milligrams of sulfolane per liter of drinking water.

“Health Canada establishes screening values ​​for contaminants at the request of federal departments, provinces and territories (jurisdictions). These requests are usually made when there is a concern for human health because a contaminant is suspected or detected in local water and the contaminant does not have an established drinking water threshold.”

Other countries do not have regulatory limits for sulfolane, but groundwater contamination from sulfolane prompted authorities in North Pole, Alaska, to list it in the US National Toxicology Program, the agency said.

Research into whether sulfolane poses a risk to human health is still ongoing, Pensini said, but some companies have already expressed concern.

“For example, leading chemical supplier Sigma Aldrich lists this hazard (in their safety data sheet),” he said in a statement to CTV News.

“There is insufficient evidence to formally report their effects on fertility.”

Crews work on a failed crude gas well south of Calgary in 2017. (Delivered/AER)

Shell works with the University of Guelph

Shell Canada says it is aware of Pensini's research and has been working with the University of Guelph since 2022.

“Shell believes a collaborative and collaborative approach with academia is key to improving environmental practices,” a Shell spokesperson wrote in an email to CTV News.

Shell, which has operated crude gas wells in the Foothills – Jumping Pound, Caroline and Waterton – for 70 years says it has worked with the Alberta Energy Regulator (AER) as well as stakeholders and landowners over the past 10 years.

In 2019, Shell sold these crude gas wells to Pieridae, but it is still responsible for “managing and remediating any impacts at the Waterton and Jumping Pound gas plants”.

Shell Canada has not acknowledged that sulfolane poses a risk to human health, but said its work with the University of Guelph is an “important step in advancing the science.”

Applicable rules for companies

According to the AER, which oversees companies in Alberta's energy sector, the province has 27,562 active crude gas wells, a figure that does not include inactive, abandoned and rehabilitated wells.

More drilling is planned, AER said in a statement to CTV News.

Among other regulations, the agency says all facilities that process raw gas need an Alberta permit. Environmental Protection and Enhancement Act (EPEA).

Contamination remains in Alberta's groundwater

Pensini admits that “practices have changed” when it comes to dealing with sulfolane.

“The contamination of the new sulfolane is not that important,” he said. “Sulfolane-contaminated filters are no longer flushed directly into aquifers.”

However, he adds, decades of contamination are still present in Alberta's groundwater.

Pennsini says the Canadian Light Source, a national research facility at the University of Saskatchewan, has been “instrumental” in understanding the spread of sulfolane.

“We can study aspects that we cannot study elsewhere, so this study is very important for us,” he said.

The results of the group were published in the journal Physics of liquids.

(Delivered/AER)

The Alberta government says it is aware of the research.

“Provincial groundwater monitoring has not detected significant increases in sulfolane levels in groundwater,” Ryan Fournier, spokesman for Environment Minister Rebecca Schultz, said in a statement to CTV News.

According to Fournier, the government will review the results of the study.