COVID-19 in Saskatoon’s wastewater has risen by 253 per cent since last week, according to new numbers from University of Saskatchewan researchers.Toxicologist John Giesy told Global News he doesn’t believe the massive increase will result in a similar rise in diagnosed new cases or hospitalizations like it has it the past, but he did say the cause of the surge could portent a coming fourth wave.“Our best estimate is that it’s about 60 per cent delta variant right now,” he said.