Many microbial diseases can be transmitted via faecally polluted waters. Unfortunately, this also is the case for SARS-CoV-2, the virus causing the current pandemic of COVID-19. BACTcontrol has been proven to be a valuable online tool, testing water with a high frequency for enzymatic activity indicating faecal pollution. BACTcontrol from microLAN / Aqualabo can be used as an early-warning system for these high-risk situations, triggering protective responses, including immediate testing for the presence of this coronavirus using qPCR methods.