Groundwater interacts with surface water systems either by effluence or influence. At coastal areas, submarine groundwater discharge (SGD) and seawater intrusion (SWI) are two main mechanisms of hydrodynamics in the coastal environment and are the dominant pathways for transport of solutes to and from marine or subterranean environments. The dynamics of this interaction and its relation to redox conditions along the flow paths is poorly understood in Indian subcontinent. We are studying such interaction, mostly as SGD at coastal areas of the Bay of Bengal. The objectives are to understand the nature and hydrogeochemical evolution of the discharging groundwater from shallow aquifer through delineated spatial zones, along with temporal or tidal variations and effects of global climate change.