Public health risk status of the water supply frame work at Kwame Nkrumah (Postgraduate) Hall, University of Nigeria, Nsukka and environs

Abstract

The aim of the study is to assess the public health risk status of the potable water supply framework at the Kwame Nkurumah Postgraduate Residence (PG) Hall, University of Nigeria, Nsukka, (UNN), Enugu State, Nigeria, and environs. Four potable water supply frame-works at the PG Hall, UNN, and exposed stagnant water were sampled and analysed in accordance with the Association of Official Analytical Chemists (AOAC) Official Method of Analysis to detect their limits of chemical and microbial constituents with high public health risk. The samples comprised of tap water (A), tap-to-reservoir water (B), commercial sachet water (C) commercial bottled water (D) and exposed stagnant water (E). The nitrate levels of all the sources (except ‘B’) were above the World Health Organisation (WHO) limit (10.00 mg/L). Thus they could cause methaemoglobinemia in infants. Nitrate content of ‘B’ (6.99 mg/L) was significantly (p < 0.05) low, relative to that of ‘A’ (23.08 mg/L); and indicated microbial action. The physicochemical and microbial quality of the tap water differed significantly (p < 0.05) from that of the tap-to-reservoir water. All the pH, except that of ‘D’, were below WHO recommended pH range (6.5 to 8.5) for drinking water. ‘D’ was more or less a mineral concentrate, as its chemical constituents were significantly (p < 0.05) higher than those of other samples. Total viable count (TVC) and coli form count of the reservoir water and sachet water (0.17 to 0.20 and 0.11 to 0.09 cfu/ml, respectively), indicated heavy microbial contamination. While ‘D’, was devoid of biological contamination. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were among the bacteria isolated. Taken together, the sampled potable water (except ‘A’ and ‘D’) was generally, of poor chemical and microbial quality; and may be considered unacceptable.

Key words: Public health risk, potable water, physicochemical and microbial water quality, water pollution.