Water Quality and Hydro-chemical Assessment for Irrigation on Baitarani River Basin, Odisha

In order to achieve a better understanding of the nature of the factors influencing surface water composition as well as to specify them quantitatively, various techniques were used to evaluate temporal and spatial variations in and to interpret large and complex water quality data sets collected from the Baitarani River Basin. It constitutes a dump of industrial and domestic rejections which contribute to the degradation of water quality. The objective of this study is to evaluate the water quality of the river and to analyze the suitability for drinking, agricultural and industrial uses. Surface water samples were analyzed for their physical and chemical properties using standard laboratory methods. Physical and chemical parameters such as PH, Turbidity, TDS, TSS, EC, DO, Alkalinity, BOD, TH, HCO3 , SO4 2, NO3 , PO4 3, Cl , Ca 2+ , Mg 2+ , Na + , K + , TC, FC, Fe and Cr were determined. The first aim is to evaluate the state of the water in this river. The second aim is to calculate the parameters of the quality of water destined for irrigation such as SAR, RSC, RSBC, MH, KR, PI and PS. A high mineralization and high concentration of major chemical elements and nutrients indicate normal value of WQI index. The PH values for all sampling locations are alkaline in nature. EC values of all the water samples are below 750, indicating good quality of irrigation water. Plotting the values of conductivity (EC) and sodium absorption ratio (SAR) on the US Salinity diagram illustrated that most of the samples fall in the category C1S1 indicates medium salinity/low sodium and C2S1 indicates low salinity/low sodium in all seasons. There exhibits a positive correlation between SSP and SAR with a coefficient of 0.7762 in both pre-monsoon and postmonsoon periods. It is reported that salinity and sodicity are the principal water quality concerns in irrigated areas, receiving such water. Saline-sodic irrigation water, coupled with limited rainfall and high evaporation, may increase soil sodicity significantly. In general, when sodium is an important component of the salts, there can be a significant amount of adsorbed sodium making the soil sodic. It shows a positive correlation between EC and SAR with a correlation coefficient (R 2 ) = 0.2834 in case of pre-monsoon season and R 2 = 0.266 in case of post-monsoon season. The positive value of R 2 shows that there is a lesser variation in the EC values and vice versa. Binary diagrams were also drawn to evaluate the origin of salts dissolved in water and it shows from the analysis that the plot of Na + versus Cl _ showed a good correlation between sodium and chloride concentration for most of the points. This confirms that the halite dissolution is behind water salinity. The plots representing Ca 2+ versus SO4 2_ concentrations yielding a good correlation between most of the points. The line representing gypsum dissolution (Ca SO4 .2H2O) indicating that gypsum dissolution is a second source of minerals in these waters after halite.Water Quality Index study reveals that close to 92.30 % of the water samples are suitable for drinking. For determination of the drinking suitability standard of surface water, parameters have been considered – TH, Piper‘s trilinear diagram and water quality index study. It has been found to be excellent in all sampling locations except one station which can be ignored in both seasons and hence poses no health risk which could arise due to excess consumption of calcium and magnesium. Hydro-geochemical facies in the form of Piper‘s trilinear diagram plot which helps in identification of the water type which can render a particular taste or odor to water, indicates that surface water is majorly of CaMgHCO3 and NaHCO3 type (fresh type) during both pre-monsoon and post-monsoon seasons barring a couple of samples which are of CaMgSO4 / CaMgClSO4 type in pre-monsoon. RSC values of all the samples are less than 1.25 meq/L, indicating that there is no complete precipitation of calcium and magnesium and the water samples are safe for irrigation purposes. However, all irrigation indices allow the water for use in irrigation purposes. This study highlights the importance of applying the water quality indices which indicate the total effect of the ecological factors on surface water quality and which gives a simple interpretation of the monitoring data to help local people in improving water quality. It provides the necessity and practicality for evaluating and interpreting the large and complex data sets, with a view to obtaining better information about water quality and the design of monitoring networks to effectively manage water resources.