Life cycle assessment of the water and wastewater system in Trondheim, Norway - A case study

This study presents the results from a life cycle assessment (LCA) performed on the water and wastewater system in the city of Trondheim. The objective of the study was to examine the system-wide life cycle environmental impact potentials of operating the city's water and wastewater system, in order to clarify the relative importance of different environmental impact categories and how different elements of the water and wastewater system contribute to these impacts. As the results of this study were used in the planning of a new carbon-neutral urban settlement, the climate change impact was of special interest. Freshwater eutrophication due to the consumption of energy and chemicals was found to be the impact category with the largest contribution to the total environmental impact. In practice, urban water utilities would have to perform a trade-off between the consumption of energy and chemicals and the discharge of pollutants to receiving waters.