Hydrochemical characterization of groundwater in lower Kali watershed, Western Uttar Pradesh

Abstract

A hydrogeochemical study was carried out to assess the groundwater quality in parts of Kali watershed in Bulandshahr and Aligarh district. 42 groundwater samples each were collected from hand pumps in pre-monsoon and post-monsoon period 2012 respectively and analysed for pH, EC, TDS, Total Hardness, silica, anions (Cl, HCO3, CO3, SO4, F & NO3) and cations (Ca, Mg, Na & K). On the basis of various diagrams and plots, groundwater has been assessed for its hydrochemical characteristics and suitability for irrigation and drinking purposes. Results show dominance of alkalis and bicarbonates. The dominant facies identified from piper diagram is Na-K-HCO3. Four chemical groups of water have been identified on L-L diagram and majority of the samples fall in alkali-bicarbonate type and mixed type groups. Possible aqueous species in the groundwater are Mg(HCO3)2, Ca(HCO3)2, NaHCO3, NaCl, CaSO4, K2SO4 and Na2SO4. The US salinity diagram and Residual Sodium Carbonate (RSC) suggest that the water is suitable for irrigation purpose. Nitrates in groundwater are within permissible limits except in 3 different locations in each season, which show high values due to the contamination from a landfill site and application of fertilizers. High positive correlation was observed between TDS and Na+, Cl-, Mg++ and Total Hardness (TH). Sodium show good correlation with Cl. Correlation of silica with Cl and TDS was done to assess the geogenic or anthropogenic involvement in evolving groundwater quality. Anthropogenic contributions from agricultural and domestic sources and weathering of rock forming minerals control the hydrochemistry of the area.