RIVM has been conducting wastewater research for almost thirty years. Back in 1992, RIVM found the poliovirus in wastewater samples. This discovery was made during a polio outbreak in an area where people were less willing to get vaccinated. Since then, RIVM has been investigating other things in wastewater water, such as antibiotic-resistant bacteria. Since 2020, these research activities have included wastewater surveillance to monitor the spread of SARS-CoV-2, the virus that causes COVID-19. All wastewater treatment plants in the Netherlands are involved in this research.