The Microbiological and Physicochemical Characteristics of Water Samples from Selected Boreholes in Umuahia, Nigeria

Abstract

Microbiological and physicochemical analyses were carried out on fifteen borehole water samples in the World Bank Housing Estate, Umuahia, Abia State, Nigeria. The microbiological analysis was based on the Most Probable Number Technique to detect fecal coliforms and other organisms present in the samples. The bacterial isolates identified included Escherichia coli, Staphylococcus aureus, Streptococcus spp, Citrobacter spp, Enterobacter aerogenes, Klebsiella pneumonia, Proteus sp, Pseudomonas aeruginosa and Serratia marscensces 63.6% of these being of the family Enterobacteriaceae. Two yeast genera identified were Saccharomyces spp and Kluyveromyces spp. The Total Heterotrophic Plate Count (THPC) gave a range of 1.1 x 10⁴ – 2.03 x 10⁵ CFU/ml, with a mean of 5.2 x 10⁴ CFU/ml, while the Total Coliform Plate Count (TCPC) gave a range of 1.1 x 10³ – 8.5 x 10⁵ CFU/ml, with a mean of 4.5 x 10³ CFU/ml. The Yeast Plate Count (YPC) ranged between 2.1 x 10¹ and 6.2 x 10¹ CFU/ml, with a mean of 4.6 x 10¹ CFU/ml. The presumptive fecal coliform ranged between 0 and 180 coliforms/100ml giving a mean of 18.73 coliforms per 100ml. E. coli/fecal coliforms were detected in 60% of the water samples. The aesthetic properties of the water samples were acceptable, although they showed high values that ranged of 221-280, 52-77, 209-301 mg/l and 200-250 us/cm for sodium, nitrate, chloride and conductivity respectively. These results show that there is need for treatment of the borehole water samples before consumption.

Keywords: Water, boreholes, microorganisms, coliforms, physicochemical analyses