Global Harmonization of Life Cycle Assessments for Small- and Medium-Scale Wastewater Treatment

Small and medium WWMs offer a potentially more sustainable alternative, but the lack of standardized life cycle assessment (LCA) approaches limits robust comparison and informed decision-making. In this study, we conduct a global harmonization of life cycle assessments of small- and medium-scale systems across 96 LCAs and 9 treatment technologies.

By harmonizing life cycle inventories, we eliminate variability in methods, assumptions, and biases, thereby providing a consistent setting to compare environmental impacts. The harmonization process shows that GHG emissions have been underrepresented in inventories. The results suggest that direct emissions to air are a key contributor to climate change, and decarbonization strategies should focus on minimizing these emissions.