Appraisal of groundwater quality for drinking and irrigation purposes in Nambiyar river basin, Tamil Nadu, India

Abstract

Chemical analysis of water samples has played a remarkable role in delineation of groundwater quality for various applications. Tirunelveli district is a semiarid region located in Tamil Nadu State in India, which is facing problem of the availability of good quality water supply during summer. The chemical quality evaluations of groundwater in Nambiyar river basin for domestic consumption and irrigation purpose are discussed in detail. Water samples were collected from 35 locations during pre-monsoon season and analyzed for physicochemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl−), sulphate (SO42−), bicarbonate (HCO3−), nitrate (NO3−), fluoride (F−), total alkalinity and total hardness. The results are evaluated and compared with World Health Organization (WHO) and Bureau of Indian Standards (BIS) water quality standards for domestic consumption. The results are interpreted with geochemical diagram such as piper trilinear diagram. The suitability of water for irrigation is evaluated based on residual Na2CO3, soluble Na percentage, Kelly’s ratio, magnesium adsorption ratio and permeability index. More than 65% of the samples found in the area are moderately suitable for irrigation.