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

Abstract

he 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
ml 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/100ml 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.