LITERATURE REVIEW
2.1 SAFE AND UNSAFE WATER
Safe drinking water is defined as one that does not represent any significant risk to health over a lifetime of consumption, including different sensitivities that may occur between life stages. In other words, this entails water having acceptable quality in terms of its physical, chemical and bacteriological parameters so that it can be safely used for drinking. In accessing the quality of drinking water, users rely principally upon their senses. Microbial, chemical and physical water constituents may affect the appearance, odour or taste of water. Although these substances may have no direct health effects, water which is highly turbid and colored or has some objectionable taste or odour may be regarded by consumers as unsafe. Taste and odour rely on close physiological processes and the originating stimuli can derive from the same substance. The interaction among taste, odour and colour can also be due to psychological factors, as users expect the sensorial information to be consistent. Consequently, the importance given by water users to drinking water organoleptics (i.e. sensorial information from taste, odour, colour and turbidity) can influence users’ perception, satisfaction, willingness to pay and selection of water sources. It is, therefore, important to understand users’ perceptions on the drinking water quality to help improve water supply services and satisfaction (Masanyiwa et al., 2019).