Surface Water Analysis for Physical Parameters, Fecal Indicator Bacteria, and Identification of the Origin of Contamination

Abstract

The prevalence of fecal indicator bacteria in relation to physical parameters were observed twice a year in selected points of the Indus River. Eight representative sampling locations were selected, and samples were collected twice a year, i.e., in the dry and wet seasons, for a total of 16 samples. The fecal coliform (FC) to fecal streptococci (FS) ratio was used to identify the source of fecal contamination. Results showed severe fecal contamination levels exceeding the allowable limits of WHO and Pak-EPA. Except for pH and TDS, the physical parameters were also not found within allowable limits at various sampling locations. The comparison of dry and wet seasons reveals higher microbial loads in the wet season. The FC/FS ratio linked polluted waters to human sources (37.5%), animal sources (25%), mixed pollution with the dominance of human pollution (25%), and mixed pollution with the dominance of domestic pollution (12.5%) in dry and human sources (25%), animal sources (25%), mixed pollution with the dominance of human pollution (37.5%) and mixed pollution with the dominance of domestic pollution (12.5%) in wet season. Pearson’s correlation test showed a strong positive correlation (r = 0.71 to 0.99) between TDS and salinity in both dry and wet seasons, and a moderately strong correlation (r = 0.41 to 0.70) between various microbial and physical parameters. It is strongly advised that careless municipal wastewater disposal into rivers be prohibited. To prevent contaminated water from mixing with river water, an appropriate sewage and drainage system should be implemented.