This file contains per Safety Region (VR), per day, the average number of SARS-CoV-2 virus particles per 100,000 inhabitants, as calculated from measurements of the number of virus particles per sewage treatment plant (RWZI). The file is structured as follows: For each date since 2020-09-07, the number of virus particles in the sewage water per 100,000 inhabitants has been calculated per VR. This number is a weighted average of the WWTPs that (partly) serve the region in question. For each date, per VR, the most recent measurement of all WWTPs is weighted according to the number of residents in the VR who use the WWTP in question, provided that the most recent measurement is not older than eight days. These values are summed over the VR, and divided by the number of observed residents (ie, the number of residents in a VR connected to WWTPs that have a measurement less than eight days old). This creates a weighted average for VR expressed per inhabitant. Multiplying this by 100,000 gives the average number of virus particles per VR, per date, per 100,000 resident equivalents. If no measurements are available from any of the WWTPs within a VR that are more recent than 8 days, the record is “NA”. The file contains, per VR, all days from 2020-09-07 up to and including the most recent date for which a value can be calculated. As a result, the most recent date may vary by region. The figures are calculated on the basis of the classification of VR as it applied on the date of the measurement. Any changes, for example as a result of municipal reorganisations, are applied on the date on which they take place administratively. The information on population numbers per WWTP and the share belonging to the various VR can be found in a turnover table, which is supplied by Statistics Netherlands (CBS). The version for 2020-2021: https://www.cbs.nl/nl-nl/maatwerk/2021/06/inwoners-per-sewage treatment plant-1-1-2021 The version for 2022: https://www.cbs .nl/nl-nl/maatwerk/2022/42/inwoners-per-sewage treatment plant-1-1-2022 You can find out which municipalities fall under a VR in the overview of area divisions of Statistics Netherlands (https://www.cbs.nl /nl-nl/dossier/nederland-regionaal/geographical-data/cbs-area classifications). All measurements of individual WWTPs on which the VR figure is based can be found in the open data set at WWTP record level. (https://data.rivm.nl/meta/srv/eng/catalog.search#/metadata/a2960b68-9d3f-4dc3-9485-600570cd52b9) Description of the variables Version: Version number of the dataset. When the content of the dataset is structurally changed (so not the daily update or a correction at record level), the version number will be adjusted (+1) and also the corresponding metadata in RIVMdata (data.rivm.nl). Date_of_report: Date on which the file was created (format: yyyy-mm-dd). Date_measurement: Date to which the calculation of the average number of virus particles per 100,000 inhabitants applies (format: yyyy-mm-dd). Region_code: The CBS code of the VR. Region_name: Name of the VR. RNA_flow_per_100000: The calculated number of SARS-CoV-2 RNA particles measured in the sewage water, based on a weighted average of the measurements at WWTPs that serve the VR in question, shown per 100,000 inhabitants. Because not all measurements are available at the same time, the most recently reported values are subject to change. This may cause differences per publication date of the data. It is also possible that earlier dates are corrected as a result of new laboratory results or corrections in source files of the Water Boards. This file is always based on the most current data.
