The objective of my research was to experimentally study and investigate the effect of grouping on pollutant dispersion from multiple stacks in which the relative impact of factors such as stack separation distance, stack array pattern and effluent exit velocity ratio were identified. The investigations were carried out at 1:200 scale in the dispersion modeling water flume using quantitative flow visualization method in which the planar laser-induced fluorescence (PLIF) technique was used to obtain cross sections of the plume concentration fields through a pixel intensity calibration against known concentration sources. The cross section concentration maps clearly show the combined plume shape and the details of the merging processes. From these measurements it was possible to determine how the use of multiple stacks in different arrangements can enhance or diminish the rate of the combined plume rise and how well the plume mixes with the surrounding atmosphere, thereby diluting and dispersing pollutants.