Assessment of Bacteriological and Physico-Chemical Quality of Water for Domestic uses in Kiamumbi Catchment, Kiambu County Kenya.

Abstract

Water quality is determined by the bacteriological and Physico-chemical parameters. The water quality of Kiamumbi Reservoir water project is of great importance because it is used for consumption in Kiamumbi Estate. This study aimed at analyzing the bacteriological and physico-chemical quality of water in Kiamumbi catchment and water supplied to households during the wet and dry seasons. Portable pH meter (Jenways), Portable TDS meter 4076 (Jenways), Portable Ec meter (Jenways), and Portable turbidity meter were used after calibration to measure pH, total dissolved solids, electrical conductivity and turbidity respectively. The highest mean pH was 7.24±0.06 recorded at the first sampling point of the feeder river. The highest level of Total dissolved solids was 217.3±21.5 at the storage facility during wet season while for turbidity was 20.5±0.85 NTU recorded at the second sampling point of the feeder river during the wet season. The highest level of electrical conductivity was 0.25±0.02µS recorded at the first sampling point of the feeder river. Heavy metals were analyzed using atomic absorption spectroscopy. The metals that were found to have concentrations above the acceptable levels were Cadmium, Chromium, Lead, Iron and Nickel. The highest mean concentration of Cadmium was 0.04 ±0.007mg/L recorded at the first sampling point of the river during the wet season. The highest mean concentration of chromium was 0.94±0.004 mg/L recorded at the reservoir during the dry season. Lead was highly concentrated during the wet season at 1.3 ±0.83 mg/L at the second sampling point of the feeder river. The highest mean concentration of iron was 0.72 ±0.18 mg/L at the first sampling point of the feeder river. The highest mean concentration of Nickel was 0.47 ±0.18 mg/L recorded at the storage facility during the dry season. The bacteriological quality of water was analyzed using the standard method for analysis of water. During the dry season, salmonella typha, pseudomonous aeruginosa, Shigella dysentriae and streptococcus were found in the river. During the wet season Citrobacter freundii, enterobacter aerogenes, Klebssiella oxycota, Proteus vulgaris and dysentriae were found to be present in the same river. Escherichia coli, pseudomonous aeruginosa, Shigella dysentriae, Streptococcus and Enterobacter aerogenes were found in the reservoir during the dry season. Escherichia coli, Citrobacter freundii, Salmonella, Shigella dysentriae, Klebssiella oxycota, and Enterobacter aerogenes were found to be present in the reservoir during the wet season. Qualitative data analysis showed that the main activities contributing to pollution were horticultural farming (96 %), Livestock keeping (71%), poultry keeping (25%), Coffee plantations (39 %), construction (36 %) and quarrying (61 %) while the sources of pollutants were found to be sewage (82 %), animal waste (71 %), fertilizers (79%), insecticides and pesticides (57%), surface run-off (79 %), construction waste (18 %) and domestic waste (4 %). The results of this study indicated that the catchment is polluted by pollutants from different sources. However, after treatment, the bacteriological quality of water was found to be within acceptable levels but the treatment method was found to be ineffective in reduction of chemical pollutants. It is for this reason that this study concluded that the water distributed to households in Kiamumbi estate is not fit for drinking and therefore a more effective treatment method should be put in place.