Wastewater surveillance has become an indispensable leading indicator of community COVID levels, providing real time data a week or so ahead of health department testing reports. Johns Hopkins environmental health scientist Dr. Natalie Exum talks with Stephanie Desmon about wastewater surveillance for COVID and tracking new variants, why it’s not a replacement for nasal testing, and how the technology could help warn hospitals about other outbreaks like flu, RSV, and antibiotic resistant strains of bacteria.