The water footprint of the wine industry: Implementation of an assessment methodology and application to a case study

An original methodology for the Water Footprint Assessment (WFA) of a Product for the wine-making industry sector is presented, with a particular focus on the evaluation procedure of the grey water. Results obtained with the proposed methodology are also presented for an Italian case study. The product was analyzed using a life-cycle approach, with the aim of studying the water volumes of each phase according to the newly-released ISO 14046 international standard. The functional unit chosen in this study is the common 0.75 liter wine bottle. An in-house software (V.I.V.A.) was implemented with the goal of accounting for all the contributions in a cradle-to-grave approach. At this stage, however, minor water volumes associated with some foreground and background processes are not assessed. The evaluation procedure was applied to a case study and green, blue, and grey water volumes were computed. Primary data were collected for a red wine produced by an Umbrian wine-making company. Results are in accordance with global average water footprint values from literature, showing a total WF of 632.2 L/bottle, with the major contribution (98.3%) given by green water, and minor contributions (1.2% and 0.5%) given by grey and blue water, respectively. A particular effort was dedicated to the definition of an improved methodology for the assessment of the virtual water volume required to dilute the load of pollutants on the environment below some reference level (Grey WF). The improved methodology was elaborated to assure the completeness of the water footprint assessment and to overcome some limitations of the reference approach. As a result, the overall WF can increase up to 3% in the most conservative hypotheses.