EVALUATION OF POLLUTANT LOAD ON NITRATES, PHOSPHATES AND FLUORIDE AND SEASONAL VARIATION FROM SELECTED DAMS AND WATER PANS IN WEST POKOT COUNTY, KENYA

In Kenya most local communities particularly in rural and semi-arid areas suffer the most due to lack of access to potable water. West Pokot is one county experiencing this problem largely due their agricultural practices of pastoralism and livestock watering around the dams and pans. This study aimed to evaluate the quality of water by assessing concentration and temporal variation of nitrates (NO3-), phosphates (PO43- ), and fluorides (F-) in three dams (Siyoi Murung, Nakuyen and Sook) and three water pans (Pampa, Kitalakapel and Limangole) in six wards of West-Pokot. Samples of water were collected in April 2025 to represent wet season and December 2025 to represent the dry season and analyzed using standard AOAC procedures. The results were then analyzed descriptively and statistically using one way ANOVA and t-test at P≤0.05 significance for spatial variation between dams and water pans. Comparisons were made with the set standards by World Health Organization (WHO). The results showed mean ranges of NO3-, and PO43-were within WHO standards for Sook dam and allowable levels in Siyoi Muruny. Pamba pan recorded the highest NO3- [24.2 ± 0.15 mg/L] seasonal variations and showed significant difference between wet and dry season (P≤0.05). The high level of pollutants in wet season could be due to storm water run offs carrying a higher load of contaminants while in dry season it is likely due to the increased solubility of ions because of the elevated water temperature causing higher evaporation rate. The levels of F- alarmingly exceeded the recommended limits in all sites but no F- was detected during the dry season at Sook dam. This suggests that heavy rainfall facilitates the leaching of fluoride-rich volcanic ash and weathered rock minerals into open water sources and the extremely high concentrations suggests the mobilization of fluoride-bearing minerals from the underlying volcanic rocks. This study advocates control measures to be taken to avoid the dams and water pans manifesting serious environmental pollution leading to health risks.