Achi news desk-
A compound used to treat sour gas that has been linked to fertility issues in cattle has been found throughout groundwater in the Prairies, according to a new study.
Scientists at the University of Guelph and the University of Saskatchewan have identified “large contaminant plumes” of sulfolane, particularly in Alberta.
Dr. Erica Pensini, an associate professor at Guelph’s engineering school, says researchers are tracking how it spreads in groundwater, work that could help identify risks to drinking water supplies.
She says the study suggests that naturally occurring sulfates (salt) react with sulfolane in groundwater and its ability to “mix more thoroughly with water.”
“Sulfate plumes travel faster with less sulfate, so we’re trying to explain migration in the context of what we can do to address this contamination,” Pensini said in a news release .
“We also work in partnership with hydrogeologists and eco-toxicologists to explore other aspects that we don’t directly explore in our lab,” Pensini said.
What is sulfolane?
Introduced to the market in 1944 by Shell Oil, Sulfolane is “widely used” to remove hydrogen sulphide – a process better known as ‘sweetening’ – from sour gas at thousands of sites across Alberta .
Sulfolane is almost invisible and does not have a particularly strong smell, so it is almost undetectable in bodies of water.
“In most cases, you wouldn’t notice its presence,” Pensini told CTV News in a statement.
According to a 2008 report by WorleyParsons Komex for Shell Energy Canada, sulfolane was first detected in groundwater in the 1980s and, in 1994, a monitoring program was implemented.
A regional sulfolane monitoring program, which began in 1998, detected sulfolane in groundwater off-site near Shell’s Waterton facility.
By 2007, Shell began working actively to remove sulfolane, building on a pilot project carried out in 2003 and 2004.
However, Pensini says the toxicity of the chemical was not fully understood, so it was disposed of improperly.
“So it was released in aquifers by sour gas and sour oil processing plants. There were 5,250 plants in 2007 (in Alberta), based on official sources,” he said.
“Each of these plants could have released different amounts.”
According to the Canadian government, “the toxic database for sulfolane is limited.”
“Overall, oral exposure to sulfolane in experimental animals was associated with immunological, renal, and reproductive and developmental effects,” the government website reads.
Health Canada says the compound is not likely to accumulate in the human body, but that more than 0.3 milligrams of sulfolane per liter of drinking water is unacceptable.
“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 the presence of a contaminant is suspected or detected in local source water and that contaminant does not have an established limit in drinking water.”
The agency says there are no regulatory limits for sulfolane in other countries, but sulfolane contamination of groundwater prompted authorities in North Pole, Alaska, to include it in the US National Toxicology Program.
Research into whether or not sulfolane poses a risk to human health is still ongoing, Pensini said, but some companies have already raised concerns.
“For example, Sigma Aldritch, a leading chemical supplier, lists this hazard in their (safety data sheets),” he told CTV News in a statement.
“There is enough evidence of its effect on fertility for these to be officially reported.”
Crews work on a decommissioned sour gas well in south Calgary in 2017. (Supplied/AER)
Shell working 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 that a cooperative and collaborative approach with academia is key to improving environmental practices,” a Shell spokesperson wrote in an email to CTV News.
Shell, which has been operating sour gas wells in the Foothills – Jumping Pound, Caroline and Waterton – for 70 years, says it has also worked with the Alberta Energy Regulator (AER) as well as stakeholders and landowners for the past 10 years .
In 2019, Shell sold those sour gas wells to Pieridae, but is still responsible for “managing and remediating any impacts at the Waterton and Jumping Pound gas plants.”
Shell Canada did not admit 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.”
Rules in place for companies
According to the AER, the body that monitors companies in Alberta’s energy sector, there are 27,562 active sour gas wells in the province, a figure that does not include inactive, abandoned and reclaimed wells.
Many more are due to be drilled, the AER said in a statement to CTV News.
In addition to other regulations, the agency says approval is required under Alberta’s for all facilities that process sour gas Environmental Protection and Improvement Act (CLOSING DATE).
Contamination remains in Alberta’s groundwater
Pensini acknowledged that “practices have changed” when it comes to handling sulfolane.
“New sulfolane contamination is probably less significant,” he said. “Sulfolane-contaminated filters are no longer flushed directly into aquifers.”
However, she adds that decades worth of contamination is still present in Alberta’s groundwater.
Pensini says Canadian Light Source, a national research facility at the University of Saskatchewan, has been “instrumental” in understanding the spread of sulfolane.
“We can explore aspects that we couldn’t explore anywhere else, so it’s really important to us for this research,” he said.
The team’s findings have been published in the journal Physics of Fluids.
(Supplied/AER)
The Alberta government says it is aware of the study.
“Provincial groundwater monitoring has not detected any notable increase in sulfone levels in groundwater,” Ryan Fournier, press secretary for Environment Minister Rebecca Schulz, said in a statement to CTV News.
Fournier says the government will review the study’s findings.
Adblock Test (Why?)
Source link
The post Sour gas additive found in Alberta groundwater – CTV News Calgary appeared first on Canada News Media.
