What is Water? To the scientist, it is the compound H2O, combining two atoms of hydrogen with one atom of oxygen. It can take the form of a solid, liquid or gas. It solidifies when cooled to O0C, boils a t 100oC when pure, and it is neither acid nor alkali. It decomposes into its two constituent; hydrogen and oxygen, at 2,500oC and at ordinary temperatures when an electric current is passed through it. (Holderness et. al, 1980).
Potable water is the water that is free form disease-producing microorganisms and chemical substances that are dangerous to health. (Lamikanra, 1999). The sanitary engineer is particularly interested in the liquid form of water. The liquid must be transported from its source to homes, offices and factories where it is being used. It must be kept free from harmful bacteria. It should be colourless, relatively odourless, tasteless and moderately soft, or free from mineral salts. (Safra et.al 1998)
Water works scientists think of Ice-water in its solid from as a nuisance causing trouble to river intakes, pipelines and hydrants. They consider water vapour only as water that has been lost from their reservoirs, EPA 2008). From the viewpoint of the public, water is an absolutely essential commodity. It makes up roughly 70% of the total weight of our bodies. It must be replenished constantly as it evaporates from the lungs and skin and passes out of the body in the form of wastes. If we were denied water for a few days, we could die of dehydration. Water is also essential for our industries. (Safra et.al 1998)
Accordingly to (Britton 1994), water is probably the most abundant as well as most important compound upon the earth. We find it in the oceans, rivers and lakes and in frozen form, in the huge ice caps of the Artic and Antarctic regions, it is present in the soil and as vapour in the atmosphere. It makes up a large percentage of plant and animal tissue including man. Its action is the principal erosive force on the earth’s surface and it is responsible for much of the variety of the landscape.
The earth would be an entirely different kind of place if there was no water in the soil and in the air for under such conditions life could not be possible. Truly our world is a “water plant”, (Britton 1994).
Water is both a reactant and a medium in which Biochemical reactions take place. Water is involved in body processes including digestion, absorption, circulation and excretion. It is the primary transporter of nutrients throughout the body and is necessary for all building functions of the body. Water helps maintain a normal body temperature and is essential for carrying waste materials out of the body (Etuk, 1997).
According to Holderness (1979), pure water does not exist in a natural state except spring water supplies are obtainable all over the world, varying in degrees of purity. Water is found to contain unwanted materials called contaminants or pollutants. These include suspended solids like heavy metals such as iron, lead etc. bacterial contaminants such as E. Coli Staphylococcus spp. and Coliforms may be present too.
According to the World Health Organization WHO (1984), water intended for human consumption must be potable, that is, the water should be free from pathogens and chemical substances deleterious to health. Consequently, good water should be wholesome and palatable. To be wholesome, water must be free from disease-producing organisms, poisonous substances, excessive amount of minerals and organic matter. To be palatable, water should be free from odour, colour, taste and suspended matter, Nancy (2009).
Since there is a great relationship between water and life, the nature of water taken into body should be assessed to be free form contaminants particularly microorganisms. This work is carried out in order to assess the quality of borehole water sold in Uyo Urban in the form of drinking water.
1.1 WATER POLLUTION
Water is said to be polluted when it contains foreign matter or contaminants at a level where it becomes a nuisance to life or cannot serve its intended purpose (Udoessien, 1997).
A river for example, is said to be polluted when its quality has deteriorated to such a level that it is no longer suitable for its intended purpose. The polluted water will not comply with the standards set by the Nigerian Standard for Drinking Water Quality which may differ from one country to another. Pure water, consisting solely of H2O molecules, does not exist; it cannot be prepared in the laboratory (David, 1972).
Rainwater dissolves gases of the atmosphere and contains particles of dust and smoke; when it runs off over the ground; it carries silt, clay and leaves into streams or rivers. These impart turbidity, colour, taste and odour to the water. Thus polluted water is highly acidic or alkaline in nature resulting in hardness. (Eruk, 1997). Pollutants may find their way into rivers through raw, domestic, industrial or agricultural sewage. Industries release poisonous chemicals containing Mercury, Arsenic, Lead, etc, into the water. (Eruk, 1997). Farms use chemical insecticides such as DDT which ‘leach’ down through the soil and pollute ground water which in turn pollutes lakes and rivers. (EPA, 2006).
1.2 SOURCES OF WATER POLLUTION
These can be of four (4) types, namely; Domestic waste; Toxic materials and industrial effluent; thermal pollution; and high concentration of inert suspended dissolved solid (Krenkel, 1994).
This includes organic matter such as phenol, xylene, and detergents. Inorganic waste such as inorganic and, alkalis etc. also water from toilet, human excrement and bathrooms. (Krenkel, 1994).
These include industrial heavy metals, radioactive materials from the atmosphere and pesticides, which can be harmful to man in one way or another. In this group also would be placed effluents from industry and pollution by crude oil, (Krenkel, 1974).
iii. Thermal Pollution
With increasing industrialization, the demand for power increases. When such power is derived from a nuclear plant, water is needed for cooling; such water becomes heated in the process and is usually discharged into rivers or estuaries. Cooling, also done in metal sinetting companies also bring about thermal pollution. (Hynes, 1978).
1.3 EFFECTS OF WATER POLLUTION (BORGANANNI, 1983)
1.3.1 Pollution by Biological Agents (Carbilt, 1997)
Protozoan sp, Algae, Fungi, Viruses, Bacteria and Animal parasites constitute biological agents some of which are potentially pathogenic. They may be found in the soil through which the water has passed, percolation of water through columns of such soil efficiently filters out numerous micro organisms such that ground water generally has low microbial count.
Some microorganisms that can be isolated in water are species of Escherichia, Enterobacter, Salmonella, Vibrio and Streptococcus. Their presence in water results in diseases such as diarrhea, typhoid fever, cholera, gastroenteritis etc.
1.3.2 Pollution by Heavy Metals
Cadmium, Lead, Mercury, Nickel sp and Zinc constitute the major heavy metals being ejected into natural water. However, it is mainly the soluble form which exerts deleterious effects on living species (Borgmanni, 1983).
Cadmium enters into water from suspended particulate land filling. There is high cadmium level in domestic sewage and sewage sludge. Lead is detrimental to human biological tissues (Hill, 1997). All heavy metals are particularly harmful to most living organisms at some level of exposure and absorption. Heavy metals cause serious contamination of fishes (Javed, 1999).
Although heavy metals may be essential to living organisms, they may, if present in high concentration become highly toxic. The toxic effect of copper in living tissues depends on the concentration and length of exposure of the organism to it (Goyer, 1993).
1.4 AIMS AND OBJECTIVES OF THE STUDY
In view of the fact that rural dwellers as well as urban dwellers now resort to boreholes for drinking water supplies, it is imperative to ascertain the quality of water from boreholes. And this forms the aims and objectives of the study. The aim of the study is to assess the Physico-chemeical quality of borehole water in Uyo Urban.
The specific objectives are as follows:
1.5 SIGNIFICANCE OF THE STUDY
Since borehole water in Uyo is mainly for drinking, the findings from this work will enable the researcher to draw in inference as to whether the water is suitable for human consumption or not.
There is no available information to consumers on the potability of borehole water hence this will be made available.
1.6 SCOPE OF THE STUDY
The scope of the study is limited to the following: