MONITORING OF POTABLE WATER QUALITY IN MAKANA LOCAL MUNICIPALITY, SOUTH AFRICA
Thandiswa NQOWANA, C. S. DUBE, R. TANDLICH
ABSTRACT. – Monitoring of potable water quality in Makana Local Municipality, South Africa. The aim of this article is to examine the physicochemical and microbial water quality from 3 sampling sites spread across municipal drinking water supply grid in Makana Local Municipality, South Africa. Samples were analysed for the concentrations of faecal coliforms, heterotrophic plate count, the chemical oxygen demand, concentrations of ammonium, phosphate and chlorides. The chloride concentrations ranged from less than 0.01 to 7.60 ± 0.08 mg/L. At the same time, the ammonium concentrations were found ranging from 0 mg/L to 1.70 ± 0.23 mg/L. For the chemical oxygen demand, the measured values ranged from 55 ± 1 to 260 ± 18 mg/L. Finally, the phosphate concentrations were shown to vary between values which were lower than 0.01 mg/L up to 1.3 ± 2.0 mg/L. There were significant differences in the values of all chemical parameters between the various sampling points and the values measured on different sampling occasions (p-value < 0.01 in all cases, Kruskal-Wallis analysis and 5 % level of significance). A total of 16 drinking water samples were tested for microbial water quality and 75 % of all samples was free of faecal contamination as indicated by the faecal coliform concentration < 0 colonyforming units per 100 mL. This percentage is lower than the data of 92-100 % of samples free of faecal contamination as published by local government. The discrepancy can be effected by the hygiene habits of the household occupants or from regrowth of organisms in the drinking water distribution system in Makana. Examination of the microbial quality of water led to the discovery of the presence of Vibrio cholera and Aeromonas hydrophila.
Keywords: physico-chemical parameters, bacteriological properties, potable water quality, drinking water distribution system