Assessment of coliforms bacteria contamination in Lake Tanganyika as bioindicators of recreational and drinking water quality

Abstract

Worldwide coliform bacteria are used as indicators of environmental and fecal contamination and hence, the possible presence of pathogenic organisms. As most people living on the shores of Lake Tanganyika use its water for cooking, drinking and washing; the monitoring of organisms indicating water pollution is more predictive of the presence of certain pathogens to protect public health. This study was carried out along the Burundian coast at 4 sampling sites (Kajaga, Nyamugari, Rumonge and Mvugo) in the months of January, February and March 2018, to assess quantitatively the presence of coliform bacteria in comparison to the standards recommended by BIS-10500 (1991, 2012) and WWF-Pakistan (2007) for drinking and recreational water quality and to sensitize the populace using the untreated water about the potential health risks. The ColonyForming Unit (CFU) method was used and the results showed that total coliform bacteriaobtained was in the range of 9000 to 60000 CFU/100 mLand are indicative of environmental contamination of all sampling stations with an average of 33250 CFU/100 mL. Fecal coliform bacteria ranged from 0 to 5000 CFU/100 mL with an overall average of 2000 CFU/100 m Land Kajaga site appeared free of contamination as fecal coliform count there was nil. The Escherichia coli count recorded ranged from 0 to 3000 CFU/100 mL with an average of 1350 CFU/100 mL. At Kajaga stations, Escherichia coli count was 0 and therefore there is no evidence of recent fecal contamination. Thus, if only fecal contamination is taken into account, the water from Kajaga station can be considered as safe for drinking and bathing purposes but incidentally total coliforms were found at Kajagastation. The water from all sampling stations require treatment before any use.