Assessment of water footprint for civil construction projects

Abstract: Water is an irreplaceable resource and the strain on it is getting tougher. Around 40 per cent of the water withdrawn in Europe is for industrial use. With a growing population and an increased demand for food and energy per capita, the demand and pressure on our water resources will increase. CEEQUAL is a rating scheme for the civil construction industry and has raised the water footprint as an important sustainability issue to consider when choosing building materials. There is however little knowledge within the industry of how to do this. This paper offers information regarding available water footprint tools and gives a practical example using two of the most developed methods; the Water Footprint Network (WFN) method and Life Cycle Analysis (LCA). The case study showed that the results are very dependent on which method one chooses. The LCA method gives a bigger footprint since it is more inclusive than the WFN method. There are however some similarities when looking at which of the materials that are high-risk and low-risk materials when it comes to freshwater footprint. Among the studied products, steel was the material that uses and consumes the most water per kilogram, and could also be imported from water scarce areas. Fill material had a low water consumption and use per kilogram, but the huge amount used in the project makes it the material that used and consumed most water in total. Fill material is most often produced locally because of the large amount used, and was therefore not as significant when weighting the results by a water stress index. Calculating a water footprint can be used as a part of declaring the environmental performance of a project by including it in an Environmental Product Declaration (EPD), a sustainability report or by setting up an Environmental Profit and Loss (E P&L) account for water. It can also be used to identify and assess risks related to water use.