LITERATURE REVIEW
2.1 Water
Water is one of the most abundant resources on which life on earth depends; in some places, availability of water is critical, limited and renewable. Shortage of water could lead to disease outbreak and economic loss, hence water is a necessity and is a unique liquid, without which life is impossible. Water plays a vital role in the proper functioning of the earth’s ecosystem. Man uses water for various purposes which include drinking, transportation, industrial and domestic use, irrigation in agriculture, recreation, fisheries, and waste disposal among others. Water that is of a good drinking quality is important to human physiology, and man’s continued existence depends so much on its availability. The WHO and UNICEF Joint Monitoring Programme (JMP) defines “improved” water sources as piped water, public taps, standpipes, tube wells, boreholes, protected dug wells, protected springs and rainwater collection. However, there are a number of unclear questions such as can protected hand dug wells provide the same microbiological quality water as boreholes which are generally deeper, and does roof water harvesting provide a good alternative where groundwater is not available (Muhamed et al., 2016).
Impurities in water may be floating as suspended matter consisting of insoluble materials of greater density than water which could be removed by sedimentation and in the form of bacteria. The bacteriological examination of water is performed routinely by microbiologists, and this will ensure a safe supply of water for drinking, bathing, swimming and other domestic and industrial uses. Microbiological examination is usually intended to identify water sources which have been contaminated with potential disease-causing micro-organisms. Such contamination generally occurs either through improperly treated sewage or improperly functioning sewage treatment system. Chemical analysis can however determine whether water is polluted and provides other useful information (Robert and Chenjo, 2013).