Using Wastewater Surveillance Data to Support the COVID-19 Response -- United States, 2020-2021. - Kirby, Amy E.; Walters, Maroya Spalding; Jennings, Wiley C.; Fugitt, Rebecca; LaCross, Nathan; Mattioli, Mia; Marsh, Zachary A.; Roberts, Virginia A.; Mercante, Jeffrey W.; Yoder, Jonathan; Hill, Vincent R. (MMWR: Morbidity & Mortality Weekly Report, 2021)