Assessment of groundwater quality using the water quality index (WQI) in and near Aligarh Muslim university campus, Aligarh, U.P., India

The study assessed the groundwater chemistry with a special emphasis on groundwater quality for drinking purposes in and near the Aligarh Muslim University campus in Aligarh. Twenty groundwater samples were collected from the AMU campus and nearby areas in February 2017. All samples were analyzed for pH, TDS, EC, TH, major ions, NO3−, and F−. The analysis revealed that groundwater was alkaline and hard, and pH, EC, TDS, TH, Ca2+, Mg2+, Na+, HCO3−, NO3−, and F− exceeded the BIS drinking water desirable limits. The Piper diagram identifies the dominant facies as Na+-K+-HCO3−, which is also evident in the Langelier-Ludwig diagram. The water quality index of groundwater varies from 63.47 to 180.33 (“Good” to “Poor” categories) with an average index of 103.72, which belongs to the “Poor” category. The bar diagram and spatial variability map of the water quality index showed that the AMU campus’s groundwater had better quality than outside the campus. This disparity may be attributed to the increased anthropogenic activities that occur outside the campus. Correlation analysis reveals that the water quality is mainly contributed by TDS, TH, Mg2+, K+, Cl−, and NO3−, and NO3−-Cl− are strongly correlated, indicating a sewage source of NO3− in the groundwater. Cluster analysis between the hydrochemical parameters also validated the results of the correlation analysis. Overall, based on the correlation and cluster analysis between the hydrochemical parameters, it was stated that the natural geogenic processes and anthropogenic activities are involved in groundwater chemistry.