Sustainable Configuration of Bioretention Systems for Nutrient Management through Life-Cycle Assessment and Cost Analysis

Abstract

The need for stormwater quality control, especially the control of nutrients, has been recognized due to the widespread problem of water eutrophication. The bioretention system, as a green infrastructure, can remove the nutrients in stormwater runoff through the adoption of an internal water storage zone (IWSZ) and ground plants. However, the design of bioretention has to be guided by a holistic sustainability assessment to avoid problem shifting. Thus, this study aims to evaluate the environmental and economic impacts of alternative bioretention system configurations relative to their flood control and nutrient management capabilities using life cycle assessment (LCA) and life cycle cost analysis (LCCA). Seven scenarios with different configurations were generated to investigate the influence of design parameters (i.e., depth of IWSZ, ground plant species) on the life cycle cost and the environmental impact categories of eutrophication, ecotoxicity, fossil fuel depletion, and global warming potential. The trade-off was observed between the nutrient removal performance, some environmental impacts, and cost. This study suggested a proper depth of 45 cm for IWSZ and the insignificance of selecting ground plant species.