PROSPECT OF VERY SHALLOW GROUNDWATER USE IN THE SALINE AND ARSENIC PRONE COASTAL AQUIFERS OF BENGAL DELTA

Use of deep groundwater is becoming an important issue in Bangladesh because of water quality problems in upper aquifers in many areas. But, installation of a deep tubewell (˃ 250m) for a household use is costly and out of reach of a low income family. Arsenic contamination in shallow groundwater at many locations makes the water unsuitable for potable use. Salinity in the coastal plain exists in the surface water in the region since long but it has increased significantly over the last three decades due to reduction of upland fresh water flow and abstraction of groundwater. As a consequence the coastal population suffers from shortage of safe water supply. It has also negative impacts on livelihood, agricultural activities, and aquatic ecosystem. Though the shallow aquifer in coastal plain generally contains salinity and arsenic but the very shallow groundwater (within 5 to 10 m) is found fresh in many areas sourced from recharge of recent precipitation. The principal objective of this research is to assess the potential of very shallow groundwater use as safe and sustainable source of drinking water in the Arsenic and Saline prone coastal area by chemical and hydraulic characterization. For fulfill this objective water samples were collected from the study area both in dry and wet seasons and monitored seasonal trends of groundwater table and salinity levels. Study reveals that people can use this very shallow fresh groundwater for drinking purpose throughout the year wherever available.