In-Stream Activities Influence Microbial Water Quality of a Shallow Mountain Stream in Rural Kenya.

The influence of periodic in-stream activities of people and livestock on the microbial water quality of the Njoro River in Kenya was monitored at two disturbed pools (Turkana Flats and Njoro Bridge) at the middle reaches. A total of ninety-six sets of samples were obtained from the two pools. On each sampling day, two trips were made before and during in-stream activities and on each trip, two sets of samples were collected upstream and downstream of activities. This schedule was repeated four times for Wednesday, Saturday and Sunday. Samples were processed for Heterotrophic Plate Count bacteria (HPC), Total Coliform (TC), presumptive Escherichia coli and presumptive Enterococci. Additional samples were analysed for Total Suspended Solids (TSS), Turbidity, BOD5 and Ammonium-N. The microbial water quality deteriorated significant (p < 0.05) downstream during activities at both pools. A similar trend was observed with the chemical indicators (TSS, Turbidity, BOD5 and Ammonium-N). The two groups of indicators demonstrated high capacity for site segregation based on pollution levels. Pollution levels for specific days were not significantly different (p > 0.05). This was incompatible with the variability of in-stream activities with specific days. The pooled data was explained largely by three significant principal components - recent pollution (PC1), metabolic activity (PC2) and residual pollution (PC3). It was concluded that the empirical site parity/disparity in the levels of microbial and non-microbial indicators reflected the diurnal periodicity of in-stream activities and the concomitant pollution they caused.

Bibliographic Details

Main Authors:	Yillia, P.T., Kreuzinger, N., Mathooko, J.M.
Format:	Report biblioteca
Language:	English
Published:	University of Sierra Leone 2000
Subjects:	Water quality, Stream flow, Microbial contamination, Dry weather,
Online Access:	http://hdl.handle.net/1834/7861
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