Meta-information on wastewater infrastructure, sampling, and testing methods.

The table shows meta-variables that substantially differed across sites. Wastewater sample analysis was conducted by the following three labs: University of Wisconsin-Milwaukee (Tuckaseigee), North Carolina State University (Raleigh 2, Raleigh 3, Cary 1, Cary 2, and Cary 3), and University of North Carolina-Chapel Hill (remaining sites). Sampling generally occurred twice weekly, though was often less frequent around holidays, and occurred only weekly in Tuckaseigee before August 2021. The concentration method used was membrane filtration with MgCl--2 (all sites) and acidification (all sites except Tuckaseigee). The extraction method used the NUCLISENSE manual magnetic bead extraction kit (all sites except Tuckaseigee) or bead bashed HA filters on a KingFisher Flex system 96 well plates (Tuckaseigee only). All sites shared the following features: Sample location type = wastewater treatment plant, System type = separated, Sample mix = raw wastewater, pre-concentration storage temp = 4°C, PCR type = Digital droplet polymerase chain reaction (ddPCR), SARS-CoV-2 targets = N1 and N2, recovery control name = Bovine coronavirus (BCoV) vaccine, endogenous control = Pepper mild mottle virus (PMMoV), extraction blanks = yes. For additional details on sample analysis methods, see previous publications (1, 2). Sites are ordered by ascending county population size. Note: Flow = 24-hr flow-weighted composite; MGD = Million gallons per day; MSD = Metropolitan Sewerage District; Time = 24-hr time-weighted composite. (XLSX)