Impact assessment of faecal sludge on groundwater and river water quality in Lucknow environs, Uttar Pradesh, India

The present study aims at Faecal Sludge (FS) characterization and assessing water quality impacted due to waste dumping in one of the India's most polluted cities, Lucknow. In order to accomplish the objective; FS, groundwater and river water were sampled from the study area in the post monsoon season. Ground water and river water data were assessed by using Piper diagram, Gibbs' diagram, Water Quality Index (WQI), Wilcox's diagram, US Salinity Laboratory's(USSL) diagram and multivariate statistical analysis. The study reveals that FS sample contains considerable amounts of electrical conductivity, cations and anions. Piper diagram demonstrates that dominance of the anions is mainly HCO3 in groundwater and river water. Whereas, Gibbs' diagram depicts that the chief source of soluble ions is weathering of rocks over which water flows. The ground water samples were grouped into excellent, good and poor while river water samples were grouped as good, poor, very poor and unsuitable for drinking as per WQI. Wilcox and USSL diagram indicated the majority of the samples are suitable for irrigation in groundwater and river water. Major Principal Components (PCs) have been identified by principal component analysis for groundwater and river water that explained 76% and 85% of the total variance in the dataset, respectively. PC1, PC2, PC3 and PC4 reflect the weathering, weathering along with anthropogenic, geochemical and anthropogenic component in groundwater, respectively. While for river water, PC1, PC2 and PC3 indicate mineral, anthropogenic and hardness component, respectively. Hierarchical cluster analysis depicts three types of cluster for groundwater and two types of cluster for river water samples based on the similarities in chemical composition. The study signifies that open dumping of waste is influencing the groundwater quality in solid waste disposal&slum area while pollution load of river water in downstream is increasing due to discharge of effluent.