Hydrogeochemistry and Groundwater Quality Evaluation in a Part of Ratnagiri District Maharashtra

Abstract

In the present work attempt has been made to determine the groundwater quality in four talukas of Ratnagiri district: Chiplun, Khed, Guhagar and Dapoli. Total 60 groundwater samples were collected from borewells and handpumps in premonsoon and postmonsoon season. The groundwater samples were analyzed for pH, EC, TDS, Ca, Na, Mg, K, HCO3, Cl, SO4, NO3, Fe and F to comprehend the hydrogeochemistry of the study area. The spatio temporal variation of the major cations and anions has been shown in interpolation maps. The groundwater has concentration of iron above permissible limit in the industrial area of LoteParshuram. Piper trilinear diagram has been plotted to understand the hydrochemical facies that showed that water is mainly Ca-Cl-HCO3 type. Durov diagram was used to know the hydrogeochemical nature of the groundwater. The scatter plot diagram of concentration of calcium and magnesium against bicarbonate and sulfate of groundwater indicates that silicate weathering is dominating the area. Chloro Alkaline Indices showed that there is direct exchange of ions in most of the samples. Trends in mineral saturation indices have been studied by the PHREEQC. The groundwater showed oversaturation of iron. Water quality index based on WHO parameters has been calculated which showed that majority of water samples are recommended for drinking purpose except few samples which have very high iron concentration. The suitability of groundwater for the purpose of Irrigation has been determined by evaluating parameters Sodium adsorption ratio (SAR), sodium percent (% Na), Residual Sodium Carbonate (RSC), Magnesium Ratio, Kelley Ratio and Permeability Index. The results showed that most of the groundwater samples are suitable for irrigation.