STUDY OF PROGRESSIVE CHANGES IN BACTERIOLOGICAL CONSTITUENT OF HARVESTED RAINWATER FROM OYOKO COMMUNITY IN KUMASI, GHANA

Abstract

The bacteriological characteristics of rainwater harvested from a typical rooftop were progressively studied for a period of nine (9) months. The study area, Oyoko, is a rural community considered as a typical farming area and located about 30 km from Kumasi, the capital city of Ashanti Region of Ghana. The collected rainwater samples were analyzed for Escherichia coli ( E. coli ) and salmonella . The entire E. coli counts varied from 0-60 CFU/100 m l and were absent on 39 observations out of total of 84 observations (replicate samples), representing 46.4%. Whiles the entire salmonella counts ranged from 0-78 CFU/100m l and only 10 observations out of the 84 were absent, which represents 11.9%. Both E. coli and salmonella showed higher concentration during early stages of continuous rainfall but, progressively reduced during later part of rainfall. The main cause of this phenomenon can be attributed to the deposition and accumulation of pollutant materials on the rooftop and catchment areas typically during the dry seasons as a result of wind-blown dirt particles and other environmental pollutants. The high bacteriological constituents in the early-stage harvested rainwater consequently have some proven significant health implications from their direct consumption. It is therefore imperative for the community to know the best time interval to harvest their rainwater as rainfall progresses, and also know any health implications associated with the harvested rainwater that goes into their storage tanks for consumption through progressive monitoring of the quality.