Origin of hydrochemicals and trace metal elements in stream waters of the Passi sub-watershed in the Mungo agricultural basin, South West Cameroon

Streams of the Passi sub-watershed, a tributary downstream of the Mungo River, are important sources of water for agro-industrial activities, irrigation, drinking and other household activities of the surrounding population. This study was conducted to determine the water quality of the Passi sub-watershed. Seven water samples were collected from different points including the confluence with the Mungo River and analyzed for physicochemical parameters, hydrochemicals and trace metal elements. Descriptive statistical analysis (DSA) and Pearson correlation were performed to show the relationship between samples and access the sources of chemicals in the watershed. pH was acidic and did not fall within the range of the World Health Organization (WHO) limits for drinking water. Fe and PO43- in a single site of Mboma were above the WHO permissible limits of the set quality standards for surface water. Pearson correlation analysis showed a significant positive correlation between Na, Ca, Mg, K, P and Cl indicating a common geogenic origin. DSA and chemical ratios revealed a significant difference in water quality of the Mboma stream which exhibited high concentrations of hydrochemicals and trace metals with respect to the other sampling points, highlighting anthropogenic influence from leaching of fertilizers and discharge of effluent from processing of palm oil. The results of this study point out the need for these stream waters to be managed properly for the benefit of the end-users.