Until Covid-19 viral exposure was an expected part of life for most people. Now, viral risk is acknowledged and often consciously calculated. 25% of all viral transmission takes place in the workplace. By the time Covid-19 is detected in one symptomatic individual, it is often widespread with multiple asymptomatic carriers. We are providing an early warning system, to detect the presence of carriers before symptoms present, and in asymptomatic carriers. Untap is a system that detects the prevalence of Covid-19 (or any other virus) in real-time in a community i.e., the approximate number of people with Covid-19 in the local population. Detection uses PCR in the wastewater: 96% positive detection rate, 100% negative detection rate and completely passive. Early detection can instate a range of measures, depending on the prevalence. Viral detection in a community can trigger workflows such as increased ventilation, reduced hot-desking, increased cleaning and more.