Results of the SARS Control project

The efficiency of the removal of the COVID-19 viral load by the water treatment process implemented at wastewater plants is one of the most relevant conclusions of the SARS Control research project. 
The consortium responsible for this project, involving the Águas de Portugal Group, the University of Lisbon and the University of Minho, presented its results on 31 March in an online session.

Contributing towards deeper knowledge on the efficiency of the sanitation barriers in effect at wastewater treatment plants and developing effective monitoring processes were the core objectives of the SARS Control research project, which sought to grasp the dynamics driving the behaviour of the SARS-CoV-2 virus responsible for COVID-19 throughout the treatment lines of urban wastewaters (liquid phase and solid phase).

Beginning in December 2020, with financial support from FEDER through the Compete 2020 program, the SARS Control project developed its activities at seven large scale treatment plants located in different parts of the country (Lisbon, Vila Nova de Gaia, Algarve, Setubal, Leiria and Guimarães) that account for over 20% of the Portuguese population. 

Throughout eight months, the project carried out the regular monitoring of SARS-CoV-2 in wastewaters and characterised the profile of behaviours of this virus (ascertained by the quantification of the respective genetic material) within the gross flow and over the different stages of treatment in each of the project participant treatment plants, out of a total of around 1,500 analysed samples. 

This verified how these plants are efficient in removing the viral load, especially in the liquid phase (water), highlighting the primary treatment phase followed by biological treatment. This also demonstrated that subsequent treatment by secondary means may further boost the effectiveness of the removal of the viral load.

This research also extended to analysing the correlation of SARS-CoV-2 with other microbiological parameters within the framework of identifying new biomarkers in order to swiftly ascertain the presence of the virus across the different wastewater phases. 

The consortium responsible for SARS Control is led by AdP VALOR, an AdP - Águas de Portugal Group company, which was also represented through the participation of sanitation managers from Águas do Algarve, Águas do Centro Litoral, Águas do Norte, Águas do Tejo Atlântico, SIMARSUL and SIMDOURO. From the national scientific and technological community, there was the participation of the Centre of Ecology, Evolution and Climate Change of the Faculty of Science, the University of Lisbon (represented by FCiências.ID, the Association for Science Research and Development), the Analysis Laboratory of the Higher Technical Institute (LAIST) of the University of Lisbon, and the Centre of Biological Engineering, the University of Minho (CEB/UMinho).

The monitoring carried out under the auspices of the SARS Control project studied the evolution of the SARS-CoV-2 viral load in the wastewaters undergoing treatment in plants and also accompanied the trends in the rise and fall of the incidence of the COVID-19 virus in the populations of the corresponding regions over the same period as well as the trends in the circulation of variants of concern (alfa and delta) in the community. 

These results have strengthened and deepened the utility of wastewater based epidemiology as a tool for complementary monitoring of the trend in the pandemic, confirming the results of previous studies, in particular the COVIDETECT project approaching the creation of an early warning system for the circulation of the SARS-CoV-2 virus in the community through analysing wastewaters, a project undertaken by a consortium bringing together the majority of the entities involved in SARS Control.

Seeking to raise awareness about the relevance of the knowledge on the effectiveness of the existing sanitation barriers in wastewater treatment plants and for developing timely and appropriate monitoring processes, the core results of SARS Control underwent presentation by the sanitation systems managers in a digital format on 31 March.

29 of March of 2022