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. Author manuscript; available in PMC: 2024 Mar 4.
Published in final edited form as: J Water Health. 2022 Aug;20(8):1197–1211. doi: 10.2166/wh.2022.094

Table 1.

Overview of case studies including information on wastewater service area, sampling, testing, and clinical case data

Characteristic Virginia Beach, VA San Jose, CA

Geographic area Atlantic Treatment Plant, Hampton Roads region, VA, USA San Jose wastewater treatment plant, Santa Clara County, CA, USA
Sewershed population 343,016 1,458,000
Wastewater sampling dates 6/2/20 to 2/9/21 3/18/20 to 3/31/21
Sampling frequency 1 per week Weekly from 3/18/20 to 7/14/20, then 5 × /week
Wastewater matrix Primary influent Primary settled solids
Number wastewater samples 37 195
Sample collection 24-h flow-weighted composite 24-h composite solids sample
Sample concentration Electronegative membrane filtration with MgCl2 addition and acidification followed by extraction via NucliSENS easyMag. Solids were not removed or allowed to settle prior to filtration. Dewatering by centrifugation at 24,000 g at 4 °C for 30 min and decanting supernatant. Extraction of 1.8 – 2.8 g of sample using the RNeasy PowerSoil total RNA kit with further purification using Zymo OneStep PCR inhibitor removal columns.
SARS-CoV-2 RNA RT-PCR target N1, N2a N
Detection technology 1-step RT-ddPCR 1-step RT-ddPCR
Case study reference Gonzalez et al. (2020, 2021) Graham et al. (2021); Kim et al. (2022); Wolfe et al. (2021)
Case data geographic area The sewershed area determined from the treatment plant service area polygon and address-level case data The sewershed service area of the treatment plant comprises approximately 75% of the cumulative cases for the entire county
Case data dates Earliest available data hierarchy: (1) illness onset date; (2) specimen collection date of earliest associated lab; (3) date of diagnosis; (4) earliest date received by local/ county health department, date received by state, date of report, investigations start date, confirmation date, investigation create date 1/27/2020 to 11/4/2021 reported by Santa Clara County Health District.

PCR, polymerase chain reaction; ddPCR, digital droplet PCR.

a

In 2021, this changed to using a single N target, a slight modification of the N2 target published by Gonzalez et al. (2020, 2021).