Assessment of Water Quality and Heavy Metal Pollution in River Ndambuk, Busia County, Kenya

Abstract

This study's objective is to determine how polluted the Ndambuk River in Busia County, Kenya, is with heavy metals and other physico-chemical parameters throughout both the dry and wet seasons. In every test point during the dry and wet seasons, turbidity was greater than the WHO-recommended threshold of 5 NTU. At sampling points 5, 6, and 7 during both seasons, pH was over the WHO-recommended limit of 6.5 to 8.5; this can be attributed to mining activities along the Kenya-Uganda border. All the sampling stations during the dry and wet seasons had levels of Lead, Cadmium, Cobalt, Nickel, and Iron that were higher than the WHO-recommended limits. At sampling points 1, 2, and 4 during the dry season and at sampling point 2 during the wet season, Chromium concentrations were, however, below the WHO standards. The significant correlation between the heavy metals suggests that metal-metal complexes are present in solution. The strong correlation between the metals, electrical conductivity, total dissolved solids and turbidity suggests that anthropogenic activities have increased, particularly in the downstream agricultural and mining areas.  This study suggests further research into the relationship between land use and heavy metal pollution, regulation of mining activities along the Kenya-Uganda border and correct agricultural practices to prevent soil erosion.