Wastewater samples from the Worcester area show the presence of COVID-19 on the decline.
Tim Loftus is the lab manager at Upper Blackstone Clean Water, which serves Worcester and 11 nearby communities.
Each week, he and other sewage treatment plant officials from across the country send samples of wastewater to a company in Cambridge, Massachusetts, for testing.
Loftus said people can get COVID-19 and show no symptoms — so they may not get tested, but they still excrete the virus.
"With all these home test kits, we don't know the infection rate out there," he said. "Because people are testing at home, and nobody's recording this. Testing through the sewer is a real effective way of measuring any disease. Right now, we're just focusing on the COVID."
Loftus said samples he submitted last week showed a significant drop from the week before.
It's similar to the trend at a wastewater treatment plant serving Boston.
Samples from a plant in Pittsfield indicate cases have been rising.
A spokesperson for the Springfield Water and Sewer Commission said it's not currently participating in the testing program.
