The study, by Rand Water researchers Yvonne Liee and Karl Lubout, found that all bottled water brands had a limited shelf life and keeping this water for much beyond a few days or weeks was likely to produce water with an unpleasant taste and smell, as well as high bacteriological counts that can affect the immuno-compromised. These include chemotherapy cancer patients, people with AIDS, organ transplant recipients, chronically ill elderly patients or very young children whose immune systems are not fully developed. On the positive side, none of the bottled water samples showed any traces of faecal pollution such as E.coli and all samples complied with SA National Standards guidelines for inorganic pollutants such as mercury, aluminium, chromium, arsenic or manganese.
The study results were presented during the Water Institute of South Africa conference at Sun City. The study noted, however, that all the brands exceeded the bacterial alert level guidelines of 5 000 colony forming units/millilitre. These bacteria, yeast and mould results were based on heterotrophic plate count tests, which are used as a general indicator test for common bacteria and do not specify which bacteria are present. Some of the bottled brands also contained algal species which could lead to taste and smell problems if they were stored for too long. The study authors said the aim of the study was to determine the shelf life of locally bottled water, and partly because Rand Water was exploring the feasibility of getting into the bottled water market. For reasons of confidentiality, the researchers did not identify the five brands of water which they tested on a monthly basis for one year.