PNNL

Abstract

The environmental impacts associated with the end-of-life (EOL) phase of construction and demolition (C&D) wood has been relatively understudied compared to earlier life cycle phases. The uncertainty associated with modeling the EOL phase of C&D products with long functional lifespans has been cited as a barrier to widespread adoption of EOL modeling in life cycle assessment studies. As such, limited studies exist for C&D wood waste treatment. In this study, four end-of-life scenarios for wood waste (recycling, composting, incinerating, and landfilling) were evaluated on a national level across the United States (U.S.), with the objectives of determining waste distribution to each scenario, scenario-specific waste transportation distances, and estimating environmental impacts, carbon storage benefits, and substitution benefits associated with each scenario. Summing the environmental impacts with the carbon storage and substitution benefits revealed a clear climate benefit for the recycling scenario in most impact categories. Moreover, when waste was diverted from the landfill scenario and recycled instead, the net environmental impacts were reduced in all impact categories. This research has improved the understanding of how differing wood waste practices across the U.S. produce different environmental impacts, which highlights areas for improvement in terms of climate and waste reduction goals.