SARS-CoV-2 monitoring at three sewersheds of different scales and complexity demonstrates distinctive relationships between wastewater measurements and COVID-19 case data

SARS-CoV-2 RNA abundance in wastewater as a function of distinct urban sewershed size

“…Likewise, our results are consistent with Haak et al 9 showing nested individual community sites with smaller populations having more peaks and valleys compared to treatment plant concentrations and with Weidhaas et al 12 that, in some cases, higher SARS-CoV-2 levels were found in contributing sample locations than in aggregate sample locations. Furthermore, in raw wastewater, Nagarkar et al 11 in a study of three sewersheds (two treatment plants in which one had a sub-sewershed also sampled) noted that normalization factors for correlating wastewater and clinical COVID-19 case data may not universally apply to individual sewersheds. We also did not find a high pairwise correlation spatial trend; although Haak et al 9 noted that, the most distant sewershed sampling sites were more poorly correlated to treatment plant influent.…”

“…4 Even before the COVID-19 pandemic, the advantage of monitoring wastewater across different sized sewershed areas has been demonstrated in previous studies on nutrient removal and energy and resource recovery in wastewater treatment, and on monitoring trace organic chemicals. [5][6][7] Community-level sampling scales of SARS-CoV-2 concentration in wastewater have been studied, [8][9][10][11][12] but without explicit consideration for the utility of nested sewershed areas along a range of metropolitan population levels, from thousands to hundreds of thousands, contributing to a common treatment plant to determine how sample pooling affects target properties. Furthermore, existing wastewater regulatory compliance monitoring is not typically conducted at sewershed sub-area catchments scales; rather, it is conducted at centralized treatment facilities or in specific industrial area effluent, which have convenient, controlled, access points for sampling.…”

Assessment of Concentration, Recovery, and Normalization of SARS-CoV-2 RNA from Two Wastewater Treatment Plants in Texas and Correlation with COVID-19 Cases in the Community

“…Previous studies recommended the normalization of SARS-CoV-2 RNA concentrations to wastewater characteristics such as fecal strength (human fecal markers like HF183, PMMoV, and crAssphage), per capita, and recovery efficiencies, although these reports indicated mixed results for correlation studies using normalized or recovery-adjusted data. 8 , 23 , 46 Some studies 46 , 47 indicated that recovery rate and fecal strength-based normalization had increased the correlation with the clinical data, while other studies 22 , 48 reported that correcting with BCoV recovery and normalizing to HF183 reduced correlations of N1/N2 wastewater measurements to COVID-19 cases. Therefore, to assess the impact of recovery rate and fecal strength, the SARS-CoV-2 N1 concentrations in the current study were normalized with the BCoV recovery rates and HF183 copies and compared with the clinical data.…”

Wastewater Surveillance of SARS-CoV-2 at a Canadian University Campus and the Impact of Wastewater Characteristics on Viral RNA Detection

“…and a mean recovery of 57% by Kumar et al 28 , 29 Various other surrogates have been applied as ICs with various recovery efficiencies, e.g., murine hepatitis virus (MHV) (6–33.5%), human Betacoronavirus-1 strain OC43 (0.2% to 4.3%), bovine coronavirus (BCoV) (0–75%), and HCoV-229E. 20 , 21 , 30 , 31 Each surrogate virus behaves differently in wastewater and might be influenced differently by wastewater characteristics. Furthermore, each surrogate virus may have different partitioning characteristics.…”