Virus particles in wastewater
Wastewater treatment plants often do not follow municipal boundaries. Although an installation is located in a specific municipality, it may also purify part of the wastewater water of surrounding municipalities.
From 4 March 2021, the dashboard also shows wastewater measurements from municipalities that do not have their own wastewater treatment plant. By using the measurements of the wastewater treatment plants to which these municipalities are connected (and using population figures from Statistics Netherlands), we can also calculate how many virus particles are in the wastewater water for municipalities without their own wastewater treatment plant.
Because the representation is per 100,000 inhabitants, those figures are comparable to other municipalities. This new calculation leads to different values at national and municipal level. Read more about the calculation of the figures on the RIVM website.