Contamination of Groundwater in the Southern Coastal Region of Andhra Pradesh

Abstract

Necessity of groundwater use and to maintain its quality is increasing enormously in many parts of the world. as the availability of surface water is very limited. Especially in coastal regions, the maintenance of groundwater quality plays a vital role due to its contamination with ocean waters. Hence, a detailed study has been conducted to assess the ground water quality in Aremanda region, which belongs to the coastal part of Andhra Pradesh. The study area is covered by alluvium soil, which belongs to Recent Era. Groundwater occurs under unconfined to semi -confined conditions in this area. Groundwater is extracted usually in this region by digging dug wells and shallow filter point wells for drinking and irrigation purposes. The groundwater is analyzed for various physico-chemical parameters and most of these parameters fall beyond the standard limits for drinking water. Groundwater occurs in alkaline nature and fresh to brackish types. The major ion chemistry indicates that the sodium and chloride are the dominant ions in groundwater. Fresh groundwater availability is due to presence of buried paleo-river channel, while brackish water caused by the extraction of groundwater through filter points and subsequently due to penetration of coastal water into aquifer system. As per the Revell’s classification, the Cl -/HCO3- ratio more than 4.5 inferred that most of the water is moderate to injuriously contaminated. The EC, SAR and RSC values also indicates that most of the groundwater is not suitable for irrigation purpose. The present attempt is made to understand how the geochemical processes controlling the groundwater quality and similar studies can be adopted in other coastal parts of the world in future. Suitable remedial measures are suggested for sustainable development of ground water in the study area.