Rainwater quality has not been an issue of concern until recent decades of increasing urbanization and industrialization. Therefore, the role of biogenic contamination sources has been always underestimated as generally, anthropogenic contaminants are thought to be responsible for rainwater quality deterioration. This study aims to find the sources and reasons of biogenic VOC emission into the air and their changes in the air. Also, transfer of biogenic VOCs into the rainwater and their abundance have been investigated. The effects of these biogenic VOCs on rainwater quality have been studied by sampling of two rain events in the University of Massachusetts in Amherst. Key water quality parameters such as UV/VIS absorbance, DOC, SUVA, chlorine residual and DBPs formation potentials have been measured and analyzed. The results show a number of high concentrations of DOC and DBP formation potentials in rainwater samples suggesting that although rainwater is still the highest quality of drinking water, but it may have some quality issues especially in terms of DBPs formation potentials that can be caused mainly by the emission of biogenic VOCs.