Comprehensive water footprint assessment of the dairy industry chain based on ISO 14046: A case study in China

Results indicate that the water scarcity footprint at the plants was not only related to total freshwater consumption and production, but also closely related to the scarcity of water resources in the watershed basin or area. The water footprint assessment focused on volume but ignored environmental impacts, which are prone to errors and deviations. For the dairy farm, the indirect water scarcity footprint accounted for more than 92% of the total water footprint and was much larger than its direct water scarcity footprint. In the dairy industry chain, cow breeding had a larger contribution to environmental water scarcity, while dairy processing was the main contributor to the water degradation footprint. The results of the water degradation footprint composition show that impact from water eutrophication pollution (NH3-N, TP and TN) was greater than that of organic pollution (COD). Furthermore, in terms of the water eutrophication footprint, nitrogen pollutants contributed to a much greater extent than phosphorus pollutants. Finally, the results highlight that the water footprint of the dairy industrial chain could be greatly reduced by increasing the water efficiency of each production process, improving wastewater treatment capacity, reducing the water footprint of the supply chain, and considering the water sustainability of the river basin.