PAST RESEARCH: Life Cycle Assessment of Green and Gray Stormwater Infrastructures

To better inform decision makers for greener and sustainable stormwater management, this research assessed and compared life-cycle environmental impacts of green, gray, and integrated green & gray stormwater infrastructures, accounting the influences of variable local characteristics and future dynamics.

Major results from this life cycle analysis research have shown that new stormwater infrastructures can significantly improve water quality and aquatic ecosystem health, but at the cost of added resource consumption and elevated GHG emissions and human toxicity impacts during the infrastructures’ construction, operation, and maintenance phases. Given the impacts of climate change, infrastructures with larger treatment capacity and higher resiliency are needed in order to effectively alleviate the impacts associated with more intense, more frequent stormwater events.  Also, improvement in infrastructure design and engineering (e.g. using low-impact or recycled materials or enhancing treatment efficiency) can largely offset the extra environmental impacts caused by the need of infrastructure upsizing. Reducing land imperviousness is an effective substitute to building new stormwater infrastructures. Finally, results have also shown, the assessment and implementation of integrated stormwater infrastructure systems and integrated wastewater and stormwater management can better assist decision makings with tradeoff dilemmas.