Abstract for presentation at 14th IUAPPA World Congress

In establishing criteria upon which stack emission limits could be based for a major project, it is recognised that carcinogens, non-carcinogens, odorous and toxic chemicals would require different approaches. This is due to the different standards being applied to air pollutants based on their characteristics. The objective of this paper is to develop a procedure for the estimation of air emission limits for new significant development projects or extension of existing facilities. This paper provides a step-wise procedure for the estimation of air emission limits using the best practice environmental standards. A criterion is developed for the selection of design standards based on a number of factors including intensity of potential impact, sensitivity and location of the receiving environment, history of a similar plant operating elsewhere, and the chemical characteristics and quantity of air emissions from the facility. In order to determine the stack emission limits various information is required such as stack emission parameters, inventory of air pollutants of concern, impact assessment criterion, air pollution modelling and dilution factors. Based on a review of the relevant literature from an existing plant or a similar plant operating elsewhere, information on air pollutants of concern is compiled. Ground level concentrations and dilution factors at the most sensitive receptors are estimated using dispersion models. Subsequently, the emissions limits are estimated using the benchmarks specially design for individual chemicals.
Keywords: stack, emission, standards, limit, impact, assessment, pollutants, dilution factor.