News From The Field

Wastewater testing for COVID-19 finding its future

USask – Since the arrival of COVID-19 in Saskatchewan, University of Saskatchewan (USask) researchers Drs. Kerry McPhedran, P.Eng., John Giesy and Markus Brinkmann have been measuring concentrations of RNA molecules in wastewater in a number of Saskatchewan communities.

Those communities are Saskatoon, Prince Albert, North Battleford, and five First Nations communities as well as USask’s student residences. McPhedran, Giesy and Brinkmann’s team includes toxicologist Dr. Paul Jones (PhD), USask Toxicology Centre post-doctoral fellow Dr. Yuwei Xie (PhD), engineering PhD student Mohsen Asadi, and research associates Dr. Femi Oloye (PhD) and Jenna Cantin.

The Public Health Agency of Canada (PHAC) has approached the team to talk about plans for a future when the seemingly unending pandemic finally subsides at least to an endemic illness in the population.

The wastewater project has now been incorporated as the Prairie Node in a National Monitoring Program co-ordinated and funded by PHAC. The federal agency will be funding chemical analyses and extending the current virus monitoring project by six months, Giesy said.

“Now that groups across Canada have all this equipment and trained a lot of people who have become experts in monitoring pathogens in wastewater, it would be very smart to keep these things going and monitor for other diseases that have been plaguing us for a while,” said Brinkmann.

These include regular influenza as well as other infections especially prevalent in Saskatchewan, such as syphilis, HIV, and tuberculosis in the north, he said. As well, small communities struggling to deal with a deadly toxic drug epidemic can prepare in advance by tracking drugs in wastewater.

This future is thanks to a relationship between USask and the City of Saskatoon that began before COVID-19 arrived. Researchers and students from USask’s Toxicology Centre were collaborating with Saskatoon’s wastewater treatment plant staff on wastewater-related projects.

McPhedran, an environmental engineer and associate professor in USask’s College of Engineering, and Brinkmann, assistant professor in the School of Environment and Sustainability at USask, have collaborated with the City of Saskatoon on several stormwater projects, including a couple of studies funded through the Natural Sciences and Engineering Research Council of Canada.

“Oftentimes the city is very engineering-oriented, and they contacted Kerry to say they’d like to work to be prepared for any future regulations on the quality of stormwater discharges,” said Brinkmann.

“He worked on measuring heavy metals, that sort of thing. I could measure several other toxicants and our lab could do toxicity tests. The research on stormwater and wastewater kind of evolved from that,” said Brinkmann.

The pandemic began in March 2020. Giesy, former Canada Research Chair in Environmental Toxicology, and Xie, who also works on the Global Water Futures environmental DNA (GWF eDNA) program, quickly developed a comprehensive system for detecting COVID-19 in wastewater in July 2020.

The accuracy of their method was validated in a study with eight other laboratories across Canada, co-ordinated by the Canadian Water Network and the Public Health Agency of Canada’s National Microbiology Laboratory in Winnipeg.

Here is how COVID-19 is detected in wastewater.  The virus is present in the feces of infected persons, even before they become symptomatic.

Researchers receive wastewater samples three times per week from the cities. The plants use automated composite samplers located at the inflow of the plants, with the computer-controlled devices sucking up a few millilitres of wastewater every 10 minutes or so into refrigerated bottles that fill up over 24 hours to be then taken to the lab.

The samples have to be collected at the right time, preserved properly and shipped to the lab, ideally within 24 hours.

“This is an RNA virus that degrades quickly in wastewater, so how the treatment is done and where the samples are taken are really important,” said Giesy.

“Markus and I aren’t wastewater engineers, but the engineering side of things is really important. We rely on Kerry to tell us what we should do.”

The results are shared in a report to the city, public health officials, PHAC and the public via a dashboard.

Because the analysis provides a cost-effective, efficient and integrative measure of infected persons in the sewer-shed, it can reliably project trends in a community approximately seven to 10 days sooner than by public clinical testing.

Ventilation system upgrades reduce COVID-19 risk

CBC Saskatchewan – Some school divisions in Saskatchewan have been upgrading their ventilation systems since the start of the pandemic, but some question how effective these upgrades are to deal with the contagious Omicron variant.

“My short answer is that the improvements will work with Omicron,” said Carey Simonson, P.Eng., a professor of mechanical engineering at the University of Saskatchewan, in an email to CBC.

“It is important to note that good filtration and ventilation do not guarantee that COVID-19 will not spread; they only reduce the risk of becoming infected. The better the filtration and the higher the ventilation rate, the lower the risk.”

Overall, ventilation and filtration are important, said Simonson. However, people cannot rely on them entirely as a sole protection from the spread of the virus. Ventilation and filtration are “one piece of the whole strategy,” he said.

Simonson also explained there is not enough evidence yet to be able to design systems for a certain risk level at the moment, such as the newer and much more contagious Omicron variant of COVID-19.

“Better filtration and more ventilation would be needed to keep the same risk level with a more contagious variant.”

Even in newer schools, ventilation systems are originally not designed for infectious disease control, said the engineering professor in an interview with CBC.

Administrators of and mechanical staff at existing school buildings should put in the best filters they can, make sure they are installed properly, and, if there is not enough air exchange, maybe add portable HEPA filter units, said Simonson.

In January 2021, Regina Public Schools announced the completed installation of new air filtration systems in all its facilities. The multi-phase project began in September 2020 and cost $1.39 million, with Regina Public Schools receiving financial support from the federal and provincial governments’ pandemic funding, the school division said in an email to CBC.

Greater Saskatoon Catholic Schools spent $1.2 million on ventilation upgrades, according to this school division.

In an online COVID-19 guide about indoor ventilation from 2021, the Public Health Agency of Canada acknowledged that these devices might be considered as an additional protection, especially where enhancing ventilation is not possible otherwise.

“When properly used, portable air filtration devices with high-efficiency particulate air (HEPA) filters have been shown to reduce the concentration of some viruses from the air,” said the PHAC.

“It’s important to note that the effectiveness of portable air filtration devices in reducing the transmission of the SARS-CoV-2 virus hasn’t yet been demonstrated. As such, they should not be used alone or as replacement for adequate ventilation, physical distancing and hygienic measures.”

Detection system for curling disables at Beijing Olympics

The Canadian Press/Mental Floss — An issue with the batteries in the curling stones at the Beijing Olympics meant moving to the honour system for hog-line violations rather than relying on the electronic detection system in them.

The electronic detection system – known as “Eye on the Hog” – was  developed in the 1990s by Saskatchewan engineering students. It is used to show that curlers have released their stone before the front of it crosses the first red line on the ice, known as the hog line. A magnetic strip is installed beneath the ice slightly behind the hog line. Inside the stone is an electrical circuit whose current is affected when you’re touching the handle.

The light initially flashes green. Release the handle before the stone reaches the magnet and at that moment, the flashing will switch to a steady green to indicate that the release was valid.

If the curler is still touching the handle when the stone crosses the in-ice magnet, the battery-operated red LEDs will be set off, meaning the curler has committed a hog line violation. The shot is disqualified, and the stone is quickly removed.

The system dates back to the late 1990s, when University of Saskatchewan engineering professor Eric Salt suggested that some of his advanced electrical engineering students invent one for a class project. With his help, they did, and Canadian engineering company Startco modified their design and brought it to market. The Canadian Curling Association soon adopted it for official use, and its popularity grew from there.

At the Beijing Olympics, a malfunction of the system was first discovered in the mixed doubles event and have also occurred during four-player team competition.

Before each throw, players grab the stone by its handle to clean the bottom of any frost or debris. A light flash from the top of the rock indicates sensor activation. The light should go out when the rock is set down.

However, curlers found the stones weren’t activating when they were flipped over. They had to ask for umpires to walk to the hog line to do the job of the sensors, which costs the curlers time and is a distraction for them.

The batteries were removed from the handles, disabling the sensors in the stones.

Potash mine to reduce water use, eliminate tailings

CBC Saskatchewan – Construction is set to begin on a Saskatchewan potash mine with a far smaller environmental footprint than industry norms, according to Gensource CEO Mike Ferguson, P.Eng.

Gensource Potash says it will begin construction this year on its ‘modular unit’ this year near the village of Tugaske, roughly 150 kilometres northwest of Regina.

The company says it will be the first Saskatchewan mine to produce no tailings ponds, and will also use far less water than other mines.

“We really believe this is the beginning of a new era of potash production. This will be the way potash is produced in the future,” Ferguson said.

A typical mine of this type requires four kg of water to produce one kilogram of potash, but Tusaske will need only about 1.5 kilograms. This will be accomplished through new technology and more extensive water recycling, he said.

Ferguson said new technology will also allow Tugaske to become the first potash mine in Saskatchewan with no tailings ponds. These often-massive surface level structures are used to store the salt and other waste products brought to the surface with the potash.

A typical mine of this type brings up two kg of salt waste for every kilogram of potash produced. The technology used at Tugaske will separate the potash before it’s brought to the surface, Ferguson said.

Ferguson said construction will only take two years, in part because of the Tugaske’s smaller scale. It’s expected to produce 250,000 tonnes of potash per year, compared with larger mines that produce millions.

Saskatchewan Environmental Society vice-president Robert Halliday, P.Eng., said water use and salt waste are two of the big concerns with potash mines. He said the Tugaske project, “certainly sounds interesting.”

Halliday noted Gensource also plans to generate power on site, which will further improve the environmental footprint.

Cameco restarting mine

CBC Saskatchewan – Cameco announced its plans to restart the McArthur River mine site and Key Lake mill sometime in 2022.

Uranium ore from the mine, which is about 630 kilometres northeast of Saskatoon, is processed at the mill, which is about 570 km northeast of Saskatoon.

Cameco president and CEO Tim Gitzel said that roughly 200 people had remained working at the two sites since the shutdown, doing care and maintenance. Once the two sites are fully operational, he expects them to employ around 900 people over the next year and a half.

The mining operation was suspended in January 2018, then shut down long-term in July 2018 due to a lengthy period of low uranium prices. Gitzel said uranium prices have dramatically risen since the decision was made to shut the two sites down – from $17 per ounce in 2018, to a current price of $42.

Gitzel believes that uranium will continue to be attractive as a green source of electricity.

“You can’t throw any of the tools out of the toolbox,” he said.

“We’re going to need every source of energy that we have going forward and nuclear is going to be one of them.”

The company expects that the McArthur River site will produce five million pounds (2.3 million kilograms) of uranium in its first year and will ramp up to 15 million pounds (6.8 million kg) by 2024.