Impact Of Anthropogenic Activities On Bacteriological Water Quality Of Nyangores River, Mara Basin-Kenya

ABSTRACT

The Mara River basin is the lifeline to Maasai Mara Game reserve in Kenya and the Serengeti

National park in Tanzania. Its major perennial tributaries are Nyangores and Amala both

originating from Mau Escarpment. Unprecedented evidence on change of land use for

development purposes in the upper catchment has affected the water quantity, quantity and the

environmental sanitation in general. In addition, the municipal town of Bomet situated close to

Nyangores River lack adequate sanitation facilities, these might have greatly degraded the water

quality through discharge of raw faecal matter into the river. Another notable area of concern is

the nearby Tenwek Mission Hospital whose waste water lagoons are located close to the bank of

the same river with their waste effluents being directly disposed to this river. Such waste disposal

methods create point and non-point sources of pollution with different degrees of pollution. This

study investigated the effect of human settlement and development on the microbial water

quality of Nyangores River at various points along its river channel based on the intensities of

human settlement and development. To establish the microbiological water quality, the study

involved the use of Membrane Filtration Technique (MFT) to determine the densities of total

coliforms, Escherichia coli, intestinal enterococci, Clostridium perfringens and Salmonella spp.

followed by plating on selective differential media for the bacteria being sought. Pollution with

easily biodegradable organic wastes was detected by Heterotrophic Plate Count (HPC)

procedures and BOD5 determination. Physico-chemical parameters; temperature, dissolved

oxygen (DO), conductivity, turbidity, total dissolved solids and pH of the water at the sampling

sites were also measured at the time of sampling using appropriate measuring meters. The

collected data was analysed using Statistical Package for Social Sciences (SPSS) version 17

software with a confidence level of 95%. The results indicated spatial and temporal variation in

the densities of faecal contamination indicators P