A comprehensive environmental and economic sustainability assessment of roadway drainage systems

stormwater;life cycle assessment

Byrne, Diana M. ; Guest ; Jeremy S.

关键词: stormwater;    life cycle assessment;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/88302/BYRNE-THESIS-2015.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The primary goal of roadway drainage systems is to quickly remove water from the roadway area to keep driving lanes safe; therefore, these systems are designed to quickly convey water that enters as runoff. However, this runoff carries pollutants (largely originating from vehicles) that travel through the drainage system and are often released to natural water bodies, thereby posing a risk to the local environment and public health over the life of the infrastructure’s operation. At the same time, the system’s construction and maintenance requires material inputs, equipment operation, and transportation that incur costs and contribute to global environmental impacts (e.g., climate change). In order to elucidate trade-offs across scales (spatial and temporal) and dimensions of sustainability (functional, environmental, economic), this research developed a comprehensive model of roadway drainage systems linking design decisions to sustainability metrics using fate and transport modeling, life cycle assessment (LCA), and life cycle costing (LCC) under uncertainty. This quantitative sustainable design framework is leveraged to characterize the implications of individual components and the system as a whole. Results showed that drainage technologies that use concrete as a construction material (basins, culverts, storm sewers, and pipe underdrains) consistently had significantly larger environmental impacts than drainage components that did not use concrete (grass swales and bioswales). While the concrete consistently dominates environmental impacts, it does not consistently govern the total cost of the drainage system. Neither cost nor masses of materials were proven to be valid cut-off criteria; however, simply accounting for the concrete in the drainage system can account for the vast majority of climate change impacts (at least 95% for all sample projects evaluated).The local water quality impacts of the operation and use phase (fate and transport of pollutants) did play a role in total life cycle impacts; however, these impacts were only noticeable relative to other life cycle phases for grass swales and bioswales, neither of which require concrete as a construction material. Although bioswales showed larger global environmental impacts as compared with grass swales, these impacts were insignificant compared to the impacts of storm sewers. The role of the operation and use phase in the total life cycle impacts of grass swales and bioswales combined with the observation that these total impacts are insignificant as compared with concrete drainage components such as storm sewers suggests that when comparing these technologies, global environmental impacts may not be relevant for decision-making. Rather, the potential local water quantity and water quality benefits of these technologies are better metrics for evaluating environmental sustainability.