Seasonal Variety on Bacteriological Evaluation of Borehole Waters in Orumba South Local Government Area in Anambra State

Aims: This study was carried out to determine the seasonal variety on physico-chemical and bacteriological evaluation of Borehole waters.

Place and Duration of Study: 10 selected borehole tanks in 5 different towns were collected from five towns from (ORS) Orumba South L. G. A; (Umunze, Onneh, Nawfija, Isulo and Ezira) in Anambra State, with one hundred and twenty samples each in both dry season (December, January, February) as January (peak of dry season) and rainy season (May, June, July) as June (peak of rainy season) within 2018.

Methodology: A total of one hundred and twenty water samples were analyzed. (1) ml of water sample was added to 10 ml single strength of the Lactose fermentation broth and serially diluted. The isolated bacterial isolates were identified using their morphological characteristics, biochemical tests, microscopical and molecular characteristics. The DNA was extracted from the identified isolates and analyzed by 16S rRNA. The bacteria isolated from the studied water samples were identified to be Bacillus subtilis (BTC), Escherichia coli (RSS), klebsiella aerogenes (TSS) and staphylococcus aureus (GY), PC – Providencia stuartii, BCD – Bacillus toyonensis, FY- Bacillus spp and ANT – Proteus spp. Frequency rate of occurrence in percentage for the isolates in dry and rainy seasons in ORS L. G. A were determined and for removal of all the isolates were within the WHO limit of 0.08ct (mg.min L-1) by the use of chlorine solution. Confirmatory profile on bacteriological in chlorine treated borehole water samples was determined.

Results: The highest TCC was recorded for sample 10 which was 27 MPN/100ml estimated during rainy season against (TCC) recorded for samples 10 which was 22 MPN/100ml during dry season. Out of eight isolates, Escherichia coli had the highest rate frequency of occurrence of 70% in rainy season against dry season. All the isolates 1 to 8 range from (0.01ct) (mg.min L-1) to (0.06ct (mg.min L-1) all the values were within the WHO recommended limit for water purity. The confirmatory test on sample locations form ORS 1 to ORS 10 for total coliform count in chlorine treated borehole water samples by most probable number estimation revealed that all the samples were within the WHO permissible limit of 0.00MPN/100ml.

Conclusions: Chlorine solution may have proven to be the cheaper and better solution for achieving water purity in boreholes water.