Water Footprints Are an Assessment of Direct and Virtual Water Use Patterns
How is it measured?
A water footprint is measured in terms of the volume of water consumed, evaporated and polluted. The Water Footprint Network, whose research provides the data that drive GRACE’s calculator, splits water footprints into three corresponding categories:
Blue Water Footprint
The amount of surface water and groundwater required (evaporated or used directly) to produce an item
Green Water Footprint
The amount of rainwater required (evaporated or used directly) to make an item.
Grey Water Footprint
The amount of freshwater required to dilute the wastewater generated in manufacturing, in order to maintain water quality , as determined by state and local standards.