Wastewater quality during the COVID-19 pandemic: a retrospective analysis of a Polish case study

Abstract The global crisis of the Coronavirus disease-2019 (COVID-19) pandemic has caused an enormous burden not only on the health, social, and economic sectors but also on many essential municipal services. Water distribution and wastewater management have faced increasing uncertainty due to the possible transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) via aerosols. Additionally, behavioral and social changes have impacted the water/wastewater services and caused the need for adaptation. In this study, the presence of SARS-CoV-2 in the influent of wastewater treatment plant located in Poland was analyzed November–December 2020, while other parameters important for the water/wastewater sector (e.g.: water usage and wastewater quality) were monitored in long-term period (2015–2020) during the working days, and holidays, including the 2020 lockdowns. In all tested wastewater samples, the genetic material of SARS-CoV-2 was detected, which confirmed the utility of wastewater monitoring to analyse the COVID-19 trends in local communities. Another important issue was the elevated presence of surfactants and the observed change in the organic matter structure in raw wastewater generated during lockdowns. Also the NGS approach and 16S rRNA amplicon sequencing confirmed the changes of functional diversity and heterogeneity in activated sludge bacterial community, especially in terms of nutrients removal and biomass separation. Thus, it is crucial to a baseline understanding of how the water-wastewater sector can serve to control disease transmission among the community and which tools should be adopted as countermeasures not only for new water consumption patterns but also for keeping safe and effective wastewater treatment. Graphical abstract