Table 2. Examples of how SARS-CoV-2 wastewater data have been used by public health departments to support their COVID-19 response, United States* .

Location	Description
Santa Clara County, California	The County of Santa Clara Emergency Operations Center and Public Health Department engaged in early evaluation of wastewater surveillance for SARS-CoV-2 in partnership with Stanford University researchers. A monitoring approach was developed to analyze SARS-CoV-2 RNA in settled solids at all 4 wastewater treatment plants in the county, accounting for >95% of the county’s total estimated population of 2 million. The county has observed trends in measured SARS-CoV-2 RNA from solids to generally track with positive COVID-19 case data. Evaluation is ongoing to understand what public health actions might be implemented in response.
Utah	Utah’s SARS-CoV-2 wastewater monitoring program began with in March 2020 as a collaboration between the Utah Department of Environmental Quality, Utah Department of Health, and 4 academic laboratories, which extended to wastewater facilities statewide by July 2020. The wastewater surveillance data have been used to help direct mobile testing teams to areas with low prevalence of clinical testing, determine where to send mask-wearing compliance observers, and assist the interpretation of other surveillance data. Consistently decreasing SARS-CoV-2 RNA concentrations in wastewater supported the conclusion that the observed declining case rates were real. Utah developed a public dashboard (https://wastewatervirus.utah.gov).
Wisconsin	The Wisconsin Department of Health Services initiated a statewide SARS-CoV-2 wastewater testing program in collaboration with the Wisconsin State Laboratory of Hygiene and the University of Wisconsin–Milwaukee. This program has monitored SARS-CoV-2 RNA concentrations in samples collected from 70 municipal wastewater treatment plants that cover 50% of the state population. Sample collection for select locations began in August 2020 and captured the pre-Thanksgiving surge in COVID-19 cases in northeastern Wisconsin. Local health departments have used these data to confirm health trends identified through clinical testing, particularly in rural areas of the state with limited testing access. Data are publicly available (https://www.dhs.wisconsin.gov/covid-19/wastewater.htm).

*Examples were provided by public health practitioners from the expert group. A detailed description of these activities is provided in the Appendix. COVID-19, coronavirus disease; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.