Assessment and Mapping of Groundwater Quality for Irrigation in and Around Areas of Paper Board Industry

Abstract

Water has become a scarce commodity due to its over exploitation as well as its pollution due to different reasons. For many important agricultural areas groundwater is the ultimate source of fresh water as surface water sources have been depleted. The quality of groundwater is important because it determines the suitability of water for drinking, and domestic and irrigation purposes. A survey was undertaken during the year 2020 to assess the quality of groundwater for irrigation in Mondipatti region of Tiruchirapalli district of Tamil Nadu. A totally 18 samples were collected from bench mark wells of (W1-W18) in and around the paper board industry and GPS locations of sampling points were recorded. The water samples were analyzed for various chemical properties viz., pH, EC, Ca2+, Mg2+, Na+ and K+; CO32-, HCO3-, Cl- and SO42-. The pH, EC, SAR and RSC in groundwater ranged from 7.6-8.4, 0.68-5.12 (dS m-1), 0.69-12.9 and -8.1 to 5.3 (meq L-1), respectively. The concentration of cations viz., Ca2+, Mg2+, K+ and Na+ varied from 1.7 to 10.8, 0.7 to 14.3, 0.009 to 0.931 and 2.8 to 39.2 meq L-1 with average of 5.4, 4.51, 0.190 and 9.24 meq L-1, respectively. The concentration of anions viz., carbonate, bicarbonates, chloride and sulphate varied from nil to 3.2, 3.2 to 9.6, 2.8 to 39.2 and 0.25 to 4.52 meq L-1 with average values of 0.64, 6.72, 11.88 and 1.31 meq L-1, respectively. The relative abundance of ions for most of the water samples were Na+ > Ca2+ > Mg2+ > K+ for cations and Cl- > HCO3-> SO42- > CO3- for anions. According to CSSRI water quality classification, 44.5, 44.5, 5.5 and 5.5 per cent of good, marginally saline, High SAR saline and Alkaline, respectively. Spatial variability maps of pH, EC, SAR and RSC of groundwater used for irrigation in and surrounding areas of paper board industry were also generated. As a result, it's critical to analyse groundwater quality not only for current use, but also as a future water source. Assessment and mapping of quality of groundwater may help the farmers in choice of crops and other agronomic management practices for getting profitable yields without affecting the soil health.