Use of LCA to evaluate solutions for water and waste infrastructure in the early planning phase of carbon-neutral urban settlements

The paper aims to discuss how life cycle assessment can be used in the early stage planning phase of new settlements. By applying the life cycle methodology on the waste, water and wastewater system of a new carbon-neutral settlement under planning in Norway, the authors discuss the pros and cons with applying this methodology in an early planning phase. The LCA methodology enabled the authors to compare suggestions from interdisciplinary planning teams, relate them to the existing systems in Trondheim and provide quantitative results back to the decision-makers, in this case the municipality. The environmental benefits of implementing alternative solutions in the waste, water and wastewater systems were found to be small. Data availability and uncertainty can be limitations in the early planning phase. By applying this methodology, the life cycle environmental impact of different solutions can be assessed at an early planning stage. Even if life cycle assessment has been used for years in the research community, there is too little experience with applying the methodology in the early planning phase of new projects. This paper discuss how life cycle assessment can be used to compare suggestions from interdisciplinary planning teams, relate them to existing systems and provide quantitative results back to the decision-makers.