When considering cases up to a week beyond the wastewater test, NPV for correctly identifying a dormitory without COVID-19 cases was 84% (95% CI = 77–91%) for detectable levels of SAR2 RNA in wastewater and 78% (95% CI = 71–84%) for quantifiable levels of SAR2 RNA in wastewater. The gene discussed is CD82; the disease is COVID-19.