The release and transport of benzene in coastal aquifers were investigated in the present study. Numerical simulations were implemented using the SEAM3D coupled with GMS, to study the behavior of benzene in the subsurface of the tidally influenced beach. The transport and fate of the benzene plume were simulated, considering advection, dispersion, sorption, biodegradation, and dissolution in the beach. Different tide amplitudes, aquifer characteristics, and pollutant release locations were studied. It was found that the tide amplitude, hydraulic conductivity, and longitudinal dispersivity were the primary factors affecting the fate and transport of benzene. Aerobic biodegradation played a significant role in plume transport and benzene fate. The tidal amplitude could influence the travel speed and the percentage of biodegradation of benzene plume in the beach. A high tidal range reduced the spreading area and enhanced the rate of benzene biodegradation. Hydraulic conductivity had an impact on plume residence time and the percentage of contaminant biodegradation. Lower hydraulic conductivity induced longer residence time in each beach portion and a higher percentage of biodegradation in the beach. The plume dispersed and the concentration decreased due to high longitudinal dispersivity.