Assessment of Pollutant Trends in a Perennial Kalpani Stream Mardan (Northern Pakistan) Using Multivariate Statistical Analysis

ABSTRACT Surface water quality assessment is very important to establish a proper water quality surveillance database for better water resources management. This study was conducted to investigate the surface water quality status of Kalpani stream in District Mardan, northern Pakistan. For this purpose, various physicochemical and biological parameters were assessed during summer and winter seasons, like pH, turbidity, total dissolved solids (TDS), electrical conductivity (EC), chloride, calcium, total hardness, sulfate, nitrate, and E. coli bacteria. In addition, multivariate statistical analyses were performed, including one‐way ANOVA, correlation matrix, and principal component analysis. Results revealed that lowest pH recorded in winter was 6.6 in the SP1 sampling point, and the highest was 8.2 in SP3, which showed alkaline characteristics throughout the study period at all three sites in both seasons. Water quality was relatively turbid in winter with a 2.02 NTU in SP1, possibly due to low water flow rate as compared to the summer. Also, NO 3 − and SO 4 2− concentrations were high during winter, recorded at 74.49 and 105.15 mg/L at SP3, respectively as compared to summer. Dilution could be one of reasons for such variations during winter and summer. The E. coli ranges 240–2000 and 73–2450 CFU/100 mL during winter and summer seasons, respectively at SP3 demonstrated enormous microbial contamination from untreated sewage and agriculture runoff. The correlation matrix revealed various physicochemical parameter pairs during winter with positive correlations, and during summer a negative correlation. Findings suggested that proper surface water quality monitoring strategies and sewage treatment measures must be established.