Assessment and evaluation of geochemical process in the groundwater of the coastal aquifers

Abstract

The quality of the groundwater in the study area was evaluated through various water quality indexes for drinking and irrigation purposes. To evaluate the water quality index, 186 groundwater samples were sampled during 2 different seasons, likely pre-monsoon (PRM) and post-monsoon (POM). The collected samples were measured for physical-chemical parameters like pH, EC, TDS, Na, K, Ca, Mg, Cl, HCO3, PO4, SO4, NO3 and H4SiO4. The research findings indicated that groundwater of the study area is approaching an alarming stage of its suitability for drinking purpose because a major percentage (i. e. 56%: PRM, 46%: POM) of samples are within poor category. Thus, the proper management strategy for water resources must be developed and a preventive management practice to address this issue must be implemented. Various water quality parameters such as electrical conductivity (EC), pH, salinity hazard, sodium hazard and permeability indexes (PI) were considered for irrigation water quality evaluation and it is inferred that the groundwater of the study area is suitable for irrigation. The PRM and POM samples with higher Na + and Cl concentrations were identified. The primary source of groundwater contamination is anthropogenic factors like domestic, agriculture effluents and mining activities. However, the groundwater of these regions is also greatly influenced by geogenic factors like weathering, rock-water interaction and precipitation which results in groundwater water level fluctuation. The research findings suggest the groundwater quality of this region is approaching an alarming stage for drinking purposes. Thus, developing a management strategy for drinking water sources and implementing preventive management practices to address this issue becomes imperative.