From ISO14046 to water footprint labeling: A case study of indicators applied to milk production in south-eastern Australia.

ABSTRACT

ISO14046 sets out principles, requirements and guidelines for the quantification of a water footprint taking a life cycle perspective. The international standard is intended to support product water footprint labeling and corporate sustainability reporting. However, the document is not prescriptive in regard to the use of any one specific water footprint indicator. In this study, water scarcity footprints were calculated for milk production on 75 farms in three parts of south-eastern Australia. Three indicators, with distinctly different conceptual basis and model structure, were applied. Included was the AWARE indicator recently developed under the UNEP-SETAC Life Cycle Initiative. The different indicator results were highly correlated (Spearman's rank correlation 0.91-0.99) and the life cycle stages and processes identified as important were the same. Therefore, all three indicators were considered suitable for informing internal strategic action. However, the different indicators produced results which differed greatly in absolute value, in some cases by a factor of >300. To enable consumers and others to make comparisons between the water scarcity footprints of different products or organisations, program (or scheme) operators will need to specify the indicator to be used. The three indicators were assessed according to scaling, interpretability and coherence with LCA results, and found to differ in terms of suitability for use in a water footprint program. The AWARE indicator was deemed to be least suitable.