నైరూప్య

A Hydrochemical Profile of Groundwater Quality of Pub Nalbari Block of Nalbari District Assam, North-East India

Pallavi Sharma and Hari Prasad Sarma

In this study, the groundwater of Pub Nalbari block of Nalbari district was investigated based on different water quality indices for drinking and agricultural purpose. Groundwater samples from hand pumps and tube wells were analyzed for pH, electrical conductivity, calcium, magnesium, total hardness, sodium, potassium, chloride, bicarbonate, carbonate and sulphate. All the physico-chemical parameters are found to be within the WHO permissible limit in most of the samples. Chemical analysis of the groundwater shows that mean concentration of cations in (meq/L) is in the order calcium > magnesium > sodium > potassium while for anions, it is bicarbonates > chlorides > carbonates > sulphates. The suitability of the groundwater for irrigation purpose was investigated by determining some factors such as sodium adsorption ratio (SAR), soluble sodium percentage (SSP), residual sodium carbonate (RSC) and electrical conductivity (EC). The value of the sodium absorption ratio and electrical conductivity of the groundwater samples were plotted in the US salinity laboratory diagram for irrigation water. Most of the groundwater samples fall in the field of C2S1 and C3S1 indicating medium to have high salinity and low sodium water, which can be used for irrigation on almost all types of soils with little doubt of exchangeable sodium. The hydrochemical facies shows that the groundwater is Ca-Mg-HCO3 type.