The California Department of Public Health (CDPH) aggregates confirmed cases of COVID-19 by sewershed restricted locations. Confirmed cases are defined as individuals with a positive molecular test, which tests for viral genetic material, such as a polymerase chain reaction test. Since wastewater data available starts from January 1st, 2021, rather than the beginning of the COVID-19 pandemic in 2020, the cumulative counts of the confirmed cases variable are shown as “NA”. Please note that values less than 5 for confirmed cases are masked (shown as “Masked”) if the sewershed population size is 50,000 or fewer, in accordance with de-identification guidelines. Values less than 3 for cases are masked (shown as “Masked”) if the sewershed population size is between 50,001 and 250,000. For no confirmed cases reported, values are set as zero.

Note: This dataset is no longer updated but is being kept for historical reference. For the Department of Public Health’s current COVID-19 testing information at any time, please see the Testing section of https://www.chicago.gov/coronavirus. Locations offering COVID-19 testing in Chicago. For a map of these locations, see https://data.cityofchicago.org/d/j2wj-wjrp. For more information on COVID-19 testing, see https://www.chicago.gov/city/en/sites/covid-19/home/managing-your-health.html?#tab-shouldtest. For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

Improvement to wastewater surveillance datasets