Researchers at Saskatoon's Global Institute for Water Security say they've found the highest amount of COVID-19 since the study began.
In a report released on Monday, the institute said samples taken on Aug. 15 and 17 showed the highest amount of COVID-19 RNA in its wastewater samples.
It showed a 348 per cent increase in viral RNA in samples taken from Aug. 12-17, compared to a week before.
"This drastic increase in viral RNA load is indicative of a significant increase in SARS-CoV-2 infections in Saskatoon," read the report.
"Which — in a partially vaccinated population — may or may not be reflected by an [increase in] case numbers in upcoming weeks."
The study, which has been running since last year, analyzes sewage samples taken from the city's wastewater treatment plant and tests it for COVID-19.
The institute said all of its samples are now of the Delta variant, and no sign of the Alpha and Gamma variants were detected.
It generally takes seven to 10 days to see an increase or decrease in cases from the time the samples are taken.
As always, results of the study will be shared with the City of Saskatoon, public health and the Public Health Agency of Canada.
There were 50 new cases of COVID-19 reported in Saskatoon on Sunday. No case numbers were released Monday.