While an abundance of information about the negative environmental impacts of bottled water exists, there are few, if any, bottom-up studies of why and how people choose and understand the water they drink, be it bottled, tap or filtered water. H204U is an interdisciplinary qualitative study funded by New York University's Sustainability Task Force to investigate the culture— the meanings, metaphors, influences, rhetoric and practices— of bottled and tap water consumption so environmental initiatives can effectively target certain populations and behavioural thresholds. The findings show that there is a gap between popular discourses about bottled water, dominated by environmentalism, marketing, and water quality, and the reasons people choose one type of water over another. Thus, its findings challenge popular assumptions about bottled water consumption, including: availability is more influential than convenience for bottled water drinkers; while a mistrust of public municipal water sources is popular in discourse, water quality is rarely a threshold attribute; environmental values and the consumption of bottled water are not mutually exclusive; and bottled water marketing has a influential, though indirect, effect on how bottled and tap water is experienced. Finally, the project finds that there are two types of initiatives that can impact bottled water consumption: initiatives that change behaviour and can be quantified, and those that attempt to change the terms of the overall discourse of water consumption, perhaps legitimizing common practices but also potentially shifting or expanding the spectrum of how water is understood. The paper ends with concrete operational and communicative recommendations modeled for New York University, where approximately a million bottled waters are consumed every month.