Hydrogeochemical characteristics of surface and groundwater: suitability for human consumption and irrigated agriculture purposes in Suruliyar sub basin, South India.

The Suruliyar sub basin in Tamil Nadu, India, was monitored for the assessment of water and soil quality. Surface water, groundwater, and soil samples were collected during the pre-monsoon (June 2016) and post-monsoon (December 2016) seasons within the sub basin area and analyzed for various physical, chemical, and biological properties, namely, pH, electrical conductivity, total dissolved solids (TDS), calcium, magnesium, sodium, nitrate, sulfate, fluoride, chloride, biological oxygen demand, chemical oxygen demand, and total and fecal coliform. All the values were compared with Indian and global standards, and the values for each parameter were within the permissible limits. However, some samples were edging toward the upward limit. Fecal coliforms (14 to 36 counts per 100 ml) were present in the river water, thus indicating anthropogenic contamination. Correlation analysis confirmed that TDS was significantly positively correlated with most of the cations and anions. Groundwater was assessed using several indices, such as the Piper diagram, United States Salinity Laboratory diagram, sodium adsorption ratio, and sodium percentage. Results showed that all the groundwater samples could be used for irrigation purposes; however, the chloride contents exceeded the permissible limit. Soil analysis results showed that all nutrients were within the permissible limits. Drought assessment showed the existence of both dry and wet years occurring most frequently, which might have a strong influence on the quality of water and soil parameters. This study suggests that the monitoring of surface, groundwater, and soil parameters is essential to maintain the sub basin area for ensuring sustainable development in the future.