Setting boundaries within a bottled water plant aid to better visualize the water use: An approach through the water footprint indicator

Abstract

In this work, the total water involved in a bottled water model plant was estimated. Total water footprint (WF), including blue, grey, and indirect components were calculated for three setting boundaries: inner (process), middle (product) and outer (industry). Total WF was obtained as the sum of the direct (operational) and the indirect (supply chain) WF. Then, five hypothetical scenarios (with regard to the base-case) were examined to find alternatives for WF reduction. In WF terms, total water use involved in the entire plant was 600% higher than the amount directly consumed (blue). The indirect WF component contributed the most to the total in all boundaries (64–78%), due to energy consumption and raw materials. Blue and grey components were the highest in the inner due to bottles filling and detergent use. Hypothetical scenarios showed us that WF values can change among established boundaries, which would directly impact on decision-making, based upon the priorities set by the stakeholders. For example, if business wants to increase production while minimizing water use, it should aim to reduce the WF of the middle boundary. Conversely, if the goal is to reach an environmental and social commitment, the plant should consider reducing the WF of the outer boundary, to reduce the electrical energy usage or to replace tap with groundwater. Defining boundaries for WF calculation is a smart tool to distinguish critical sectors so that business could decide where and how to apply (or not) actions towards more efficient production.