The methods available to calculate a water footprint of a product or process have developed significantly over the past several years. Recent methods recognise that there are two main impacts associated with water use: consumption and degradation, and these impacts can occur either directly at a production facility, or indirectly within a producer’s supply chain. In this paper examples are provided showing how these methods can be applied to mining, mineral processing and metal production systems, with a particular focus on copper, gold and nickel production.
Water footprinting methods can be used in a variety of ways. The water stress index of different areas can be used to benchmark sites operating in different regions and to understand the water supply risks facing major mineral and metal commodities. The process of preparing a water footprint of an operation can also reveal significant opportunities for water savings at individual sites.