Students walk at the campus of North Carolina State University in Raleigh, North Carolina, U.S. August 7, 2020. Picture taken August 7, 2020. REUTERS/Jonathan Drake
Back to school in the age of coronavirus
06:23 - Source: CNN
CNN  — 

When Rosa Inchausti and her colleagues started testing wastewater in Tempe, Arizona, it was 2018 and they were not looking for coronavirus. They were tracking the opioid epidemic.

But because they were set up to sample the city sector by sector, they were able to swit