Road construction and connected activities such as earthmovings, materials production and transportation, tunnel excavation and bridge erection, machineries and plant operation, produce significant burdens on environment and communities, although the temporary character. By 2050, more than 25 million kilometers of new roads are expected to be built, the 90% of which will be in developed countries. This figures justify the growing attention and interest towards the environmental and social impacts of road costructions. For the World Bank, the transport sector accounts for nearly 14% of global GHG emissions and approximately the 72% of these emissions are caused by construction, rehabilitation, maintenance, and usage of roads. Among the emissions, a significant role is played by the particular matter (PM), released by the off-road diesel equipment and generated by the earthmovings and material production and transportation, which temporarily affects the local air quality. The estimation of the PM emissions, the assessment of their admissibility in terms of compliance with the limit imposed by the regulations and the identification of the mitigation measures are fundamental steps towards sustainable and cleaner constructions. In this paper, an estimation of PM10 emissions and their propagation in the air due to the construction of an Italian motorway has been carried out. To do this all the construction activities, the construction sites and the type and operation time of off-road machines and plants that will be used in each site have been considered and analysed in emissive terms. A modeling simulation of the impacts on the air quality was carried out through the following procedure: i) quantification of PM10 emissions released during the construction activities; ii) weather-diffusion characterization of the area subject to site operations; iii) modeling simulation using the CALPUFF model and estimation of the average daily and average annual concentrations of PM10 expected in the area; iv) calculation of the total PM10 concentration expected in the area, adding the construction contribution to the background level; v) evaluation of the results in relation to the regulatory limits in force. Results showed that in the worksites the average annual concentration of PM10 is always below the limit of Italian regulation, while the average daily concentration is higher than the limit value inside the worksites. However this concentration decreases rapidly in few meters. Simulations have been carried out considering the total absence of mitigation measures and procedures (i.e. wetting) aimed at controlling the dusts emission and dispersion. Notwithstanding the substantial compliance of PM10 concentration with the Italian regulation, the outcomes provide useful indication on how identify the effective mitigation measures, activity-specific and site-specific, at project stage and valuable guidelines for setting up a feasible monitoring system, which timely controls and supervises the on-site emissions. For example, in an earthwork activity, the controllers should pay intensive attention to the materials transportation and storage and adopt proper mitigation measures further tailored, work in progress, in function of the outcomes of the monitoring system
Sustainable and cleaner road construction: estimation of air pollution arising from worksite activities
GIUNTA M
2020-01-01
Abstract
Road construction and connected activities such as earthmovings, materials production and transportation, tunnel excavation and bridge erection, machineries and plant operation, produce significant burdens on environment and communities, although the temporary character. By 2050, more than 25 million kilometers of new roads are expected to be built, the 90% of which will be in developed countries. This figures justify the growing attention and interest towards the environmental and social impacts of road costructions. For the World Bank, the transport sector accounts for nearly 14% of global GHG emissions and approximately the 72% of these emissions are caused by construction, rehabilitation, maintenance, and usage of roads. Among the emissions, a significant role is played by the particular matter (PM), released by the off-road diesel equipment and generated by the earthmovings and material production and transportation, which temporarily affects the local air quality. The estimation of the PM emissions, the assessment of their admissibility in terms of compliance with the limit imposed by the regulations and the identification of the mitigation measures are fundamental steps towards sustainable and cleaner constructions. In this paper, an estimation of PM10 emissions and their propagation in the air due to the construction of an Italian motorway has been carried out. To do this all the construction activities, the construction sites and the type and operation time of off-road machines and plants that will be used in each site have been considered and analysed in emissive terms. A modeling simulation of the impacts on the air quality was carried out through the following procedure: i) quantification of PM10 emissions released during the construction activities; ii) weather-diffusion characterization of the area subject to site operations; iii) modeling simulation using the CALPUFF model and estimation of the average daily and average annual concentrations of PM10 expected in the area; iv) calculation of the total PM10 concentration expected in the area, adding the construction contribution to the background level; v) evaluation of the results in relation to the regulatory limits in force. Results showed that in the worksites the average annual concentration of PM10 is always below the limit of Italian regulation, while the average daily concentration is higher than the limit value inside the worksites. However this concentration decreases rapidly in few meters. Simulations have been carried out considering the total absence of mitigation measures and procedures (i.e. wetting) aimed at controlling the dusts emission and dispersion. Notwithstanding the substantial compliance of PM10 concentration with the Italian regulation, the outcomes provide useful indication on how identify the effective mitigation measures, activity-specific and site-specific, at project stage and valuable guidelines for setting up a feasible monitoring system, which timely controls and supervises the on-site emissions. For example, in an earthwork activity, the controllers should pay intensive attention to the materials transportation and storage and adopt proper mitigation measures further tailored, work in progress, in function of the outcomes of the monitoring systemI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
