A Case Study of the Effect of Seawater Intrusion on the Water Quality Index of the Indian Southeastern Coastal Region

Abstract

Safe and clean acceptable quality of water is essential for the survival of life. There are severe problems with the insufficient availability of safe groundwater for human consumption. The present study aims to evaluate the groundwater quality in the coastal area of Srikakulam district, located in the extreme northeastern direction of Andhra Pradesh in India. The study area spreads over an area of 130 km 2 . In this study, groundwater is the major source for drinking and irrigation purposes. A total of 20 bore well (BW) groundwater samples were collected with a distance of 5 km each during the period of the premonsoon and monsoon seasons of 2020. This study investigates the importance of groundwater quality in some areas of the coastal villages in the Srikakulam district. The overall water quality condition is explained with various physicochemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), total alkalinity (TA), calcium (Ca 2+ ), magnesium (Mg 2+ ), fluoride (F − ), chloride (Cl − ), nitrate (NO 3 − ), sulfate (SO 4 2−), sodium (Na + ), potassium (K + ), and turbidity. The water quality is assessed on the basis of the water quality index (WQI) method. The physicochemical results are compared to the water quality standards of the World Health Organization (WHO), 2012, and the Bureau of Indian Standards (BIS), 2012. The correlations between the values have been presented for various parameters. The water quality index (WQI) ranged between 11.56 and 61.27, the highest value recorded at M. Ganguwada and the lowest at Bandaravanipeta. The analytical results showed that around 90% of the samples are extremely hard in their nature and that their Na + and Cl − concentrations are also higher. It indicates that the coastal region is influenced by seawater intrusion.