One of Patrick Green’s first orders of business each day is to open a tap and fill a bottle with sludge.
A utilities plant operator in Modesto, a city of nearly a quarter-million people in California’s San Joaquin Valley, Green’s primary job is to help keep the city’s sewers flowing and its wastewater treated to acceptable levels of safety. But in recent months, he and his colleagues have added COVID-19 sleuthing to their job description.
At the treatment plant where Modesto’s sewer pipes converge, larger items, ranging from not-supposed-to-be-flushed baby wipes to car parts, are filtered out. What remains is ushered into a giant vat, where the solids settle to the bottom. It’s from that 3-feet-deep dark sludge that researchers siphon samples in their search for SARS-CoV-2, the virus that causes COVID.
Across the country, academics, private companies, public health departments, and sewage plant operators have been working to hone a new public health tool, one with uses that could reach well beyond COVID.