Life Cycle Sustainability Assessment of Fugitive Dust Control Methods

Fugitive dust at construction sites reduces air quality and can affect respiratory health. Contractors must often use dust control strategies to meet environmental regulations for dust mitigation. Water application is the most common mitigation strategy, although alternatives such as magnesium chloride (${\mathrm{MgCl}}_2$) are also used. Although these strategies reduce fugitive dust emissions at the site, they cause other environmental impacts onsite and off-site throughout their life cycle. A new approach to dust mitigation, enzyme-induced carbonate precipitation (EICP), has been developed to improve dust mitigation while reducing life cycle impacts. A life cycle sustainability assessment (LCSA) was performed to compare common dust mitigation strategies with EICP across a variety of environmental impacts and cost. LCSA has not previously been applied to dust mitigation strategies, so this work contributes new knowledge on the sustainability of existing and novel approaches to dust mitigation. The results show that EICP is potentially more sustainable than water application, particularly as watering frequency or persistence of the EICP treatment increases. Compared with ${\mathrm{MgCl}}_2$, EICP may be more environmentally intensive and more expensive. However, indicators for salinization of water and soil, impacts of concern for ${\mathrm{MgCl}}_2$, do not exist, making the comparison incomplete. It is anticipated that with further research and development focused on preventing EICP process emissions, enhancing the durability of EICP treatment, and reducing production costs, the technology will become more favorable for fugitive dust control.