Life cycle environmental and economic assessment of a LID-BMP treatment train system: A case study in China

A cost-combined life-cycle assessment was conducted to estimate the environmental and economic burdens of a low impact development best management practice (LID-BMP) treatment train system in China. Results showed that climate change, human toxicity, terrestrial ecotoxicity, freshwater ecotoxicity, marine ecotoxicity and fossil depletion dominantly contributed to the overall environmental effect. Infiltration pit exhibited the highest environmental effects because of high consumption of PVC and non-woven fabrics, whereas grassed swale and buffer strip had the lowest environmental impacts. The operation phase showed great environmental benefits because a LID-BMP treatment train system can significantly reduce the emissions of heavy metals, suspended solids, total nitrogen, and total phosphorus to water. From an economic perspective, constructed wetland exhibited the highest economic burdens where the costs of graded gravel and bedding plants had a significant function, whereas grassed swale had the lowest economic burdens because of low consumption of raw materials. Optimizing the efficiency of PVC, non-woven fabric consumption, and road transport is an effective way to improve the potential environmental performance of LID-BMP construction phase.