We are constantly reminded, through the appeals on television and through print media, of the plight of those who are forced to drink from contaminated water sources and the terrible toll on their health and, ultimately, their lives. It is therefore especially important that we do not lose sight of the value of having this precious commodity delivered to our homes and businesses, and having it available with the turn of a tap. Before complaining about the price we pay for the service, we should perhaps consider the cost of being without such a facility.

In the case of drinking water, the crucial need for quality testing is fairly self-evident, but there are also many other situations in which it is equally important and where, on occasion, an even higher degree of purity may actually prove to be necessary. A number of different treatments will normally be required in order to purify this essential liquid and these also serve to determine the methods used to evaluate their results. In practice, the subsequent analysis of samples tends to focus on three main areas, namely the physical, chemical, and biological composition of the liquid, following treatment.

Typically, the physical components are insoluble particles of various sizes and are readily removed by a combination of sedimentation and filtration. Thereafter, a nephelometer can be used to measure any residual turbidity that might suggest that further treatment is needed. The removal of unwanted chemical content is a little trickier, but is often achieved with the use of ion-exchange resins and specific qualitative testing of the treated water to confirm their removal. Finally, a combination of ultrafiltration and chlorination is used to ensure the removal of potentially harmful microorganisms, which may then be confirmed with suitable microbial culture techniques.

In South Africa, municipalities are most often responsible for the supply and distribution of this life-giving commodity as well as for the collection and subsequent treatment of the wastewater discharged from the sinks and toilets of domestic users, and from a vast array of industrial processes. At various stages during the treatment process, the need for an efficient form of quality testing is essential. In some cases, this may be necessary to ensure that the treated effluent is sufficiently pure, to be returned safely to the environment where it may be required to sustain life in rivers and dams and to ensure that it is, in due course once again of a standard that is suitable for the production of potable water with the necessary processing. In cases where the treated effluent is to be re-used in some industrial process, possibly as part of a company’s conservation programme, the purification methods required will not normally be quite as stringent.

In the food and pharmaceutical industries, the need for a high degree of purity is obvious and, equally obviously, the quality of water used in the preparation of foods and medicines must be closely monitored by means of an established programme of testing. IEPSA is a specialist supplier of the equipment and reagents used in a wide range of quality control applications by many of South Africa’s essential industries.

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