Air Pollution Modelling for a Proposed Limestone Quarry

Abstract

Predictions of the air pollution impact of a proposed opencastlimestone quarry have been made using meteorological data, information on various quarrying activities and their associatedemission factors, baseline air quality and a validated modelconditions. Results have indicated that the haul routes and ore processing plant are the major sources of suspended particulatematter (SPM) emissions. The emission rates of other air pollutants are insignificant. It has been predicted that 24-hraverage SPM concentrations due to quarrying activities would be around 360 μg m^-3 in the work zone and less than 130 μg m^-3 beyond the site boundary. The total 24-hr average SPM concentration beyond the site boundary would be below 500 μg m^-3, which is the national air qualitystandard for SPM in an industrial area. Therefore, the impact of opencast extraction on the local air quality would be acceptable. However, implementation of a green belt comprisingof various tree species which will act as a dust attenuator of40 m width around the site boundary, along with efficient control measures at source, would effectively mitigate and minimize pollution impacts from the quarry. The effectivenessof the green belt around the quarry site has been assessed and a sensitivity analysis has been carried out for different parameters, namely, tree height, width of green belt, and distance of receptor from the source. The technique for designing a green belt around a quarry site has also been described.