Are We Paying More to Consume Substandard Drinking Water? Crowd-Sourced Water Education Study in a South-Asian Megacity

South. Environment and health-related data are inadequate and strongly rely on governmental-mediated observation. The present work is the first of its kind attempt to gather relevant information on potable water quality using mass citizen engagement over a south Asian megacity, Kolkata. The city has a long history associated with water-borne diseases and presently numerous reports on sickness from drinking water contamination have been published in the local newspapers. The current work crowdsourced water sampling throughout the city and analyzed information regarding biological contaminants for five existing water types. 300 citizens were mobilized and trained in water collection through audio-visual communication workshops and together 570 samples of water have been collected from different parts of the city. Water sample collecting points were created over the city and samples were taken to the analysis hub where it was analyzed for standard coliform test and for total dissolved solid (TDS) and pH. The results show that the most expensive water types (20l commercialized packaged drinking water bottles) are the worst in terms of water quality. Governmental-free drinking water was found to be much safer as compared to packaged drinking water. 44% of the packaged drinking water was found to be contaminated with coliform bacteria and we did a comparative analysis with reports from different developing countries and found that such high occurrence was not reported in any cities across the world. We communicated the results to the participants and further, conducted semi-structured interviews to understand the perception of water quality and the driving force behind the choice of a particular water type. It was also found that logistical feasibility is the primary reason behind selecting the 20l bottle. The blind faith in commercially packaged drinking water has been reflected in the interview. The present studies confirm the potential of crowdsourcing of environmental-health data in the global south and successfully accomplish potable water analysis through crowdsource sampling over a south Asian megacity. Such robust methods could be easily scaled up and follow-up discussions can definitely improve water literacy among the participants in Global South.