ASSESSMENT OF WATER-QUALITY PROBLEMS DUE TO MICROBIAL-GROWTH IN DRINKING-WATER DISTRIBUTION-SYSTEMS

The microbiological quality of water in the potable water distribution system of a major South African metropolitan area was studied. Water samples were collected from private houses, apartment buildings, and public institutions over a period of two years. Total coliform bacteria were isolated from 33% of the water samples, of which 10% exceeded the South African recommended guidelines. Fecal coliform bacteria were isolated from 10% of the samples tested. Twenty-five different fungal cultures were isolated. The dominant bacteria found were of the genus Bacillus. Other organisms were Staphylococcus, Micrococcus, Acinetobacter, Flavobacterium, Aeromonas, Klebsiella, Citrobacter, and Escherichia coli. Legionella bacteria were isolated occasionally. Higher bacterial counts were found in apartment buildings than in private houses. The age of the plumbing system was also found to result in potable water of a poorer microbial quality. (C) 1995 by John Wiley & Sons, Inc.