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 switch gears and begin sampling sewage for evidence of coronavirus.
"We were ready for this," Inchausti told CNN.
Now the city is regularly sampling sewers to keep an eye on the pandemic. And things are not looking good in parts of Tempe.
And they're not looking good in Boston, or in Reno, Nevada, or in many other cities across the country.