The introduction of the concept of water footprint by Hoekstra in 2002 showed that the use of water should be taken into account throughout the supply chain. The water footprint demonstrates not only the direct use of water by a consumer or producer, but also fresh water use in relation to the use of indirect water. The water footprint of a product is the volume of fresh water measured throughout the supply chain and used when manufacturing a product. The water footprint is a multi-dimensional indicator. It shows the water volume according to its source, water type in green, blue or gray as well as when and where it is used. All components of the water footprint are specified geographically and temporally (Hoekstra, Chapagain, Aldaya, & Mekonnen, 2011).
The water quality has three main components (WWF, 2014):
Blue Water Footprint is used for the total volume of surface and ground water resources, also known as freshwater, required to produce an item.
Green Water Footprint is the amount of rainwater required to make an item. This rainwater remains in or on the ground without getting mixed with groundwater.
Gray Water Footprint is the amount of fresh water used to eliminate or reduce pollution load in the water. Industrial growth and population increase should be taken into consideration when calculating the gray water footprint, which is a water pollution indicator.