1.1 Background of the study
The Federal Environmental Protection Agency (FEPA) Act Section 38 of Cap 131 LFN (1990) also defines pollution to mean man-made or man-aided alteration of chemical, physical, or biological quality of the environment to the extent that it is detrimental to that environment or beyond acceptable limits. Water pollution results when unwanted substances enter in to water, which changes either the physical, biological 0r chemical quality of water which can result to harmful to environment and human health (Mehtabet al., 2017). Since the 1990s, the issues of water pollution has became major concerned in almost all rivers in Africa, Asia and Latin America. The weakening of water quality is expected to rise over the next decades and this will increase threats to human health, the environment and sustainable development. An estimated 80% of all industrial and municipal wastewater is get in to the environment without any prior treatment, leading to the growing deterioration of overall water quality with detrimental impacts on human health and ecosystems in general (UN Water Report, 2018).
Man made activities such as improper waste disposal, agricultural practice, pesticide and fertilizer application, discharge of plastics and polythene bags in to water bodies. Urbanization and weak management systems are the common leading factor for the influencing water quality in the world (Mehtabetal., 2017).
Discharge of domestic waste, industrial effluent, marine dumping, radioactive waste are main causes of water pollution. Chemicals are disposed off and industrial waste can accumulate in lakes and river, proving harmful to humans and animals (Mehtabet al., 2017). Toxic from industrial waste are the major cause of immune suppression, reproductive failure and acute poisoning. Infectious diseases, like cholera, typhoid fever and other diseases gastroenteritis, diarrhea, vomiting, skin and kidney problem can transfer through polluted water. Polluted water can contaminate plant leading to render it to be unfit for human consumption as well as animals which can have effect to their health when feed (Mehtabet al., 2017). Water pollutants are killing sea weeds, mollusks, marine birds, fishes, crustaceans and other sea organisms that serve as food for human(Mehtabet al., 2017).
It is reported that 75 to 80% water pollution is caused by the household sewage, Waste from the industries like, sugar, textile, electroplating, pesticides and paper are polluting the water, Polluted river have intolerable smell and contains less plant and animals(Mehtabet al., 2017). 80% of the world’s population is facing threats to water security (Mehtabet al., 2017). Large amount of domestic sewage is disposed in to river and most of the sewage is untreated. Domestic sewage contains toxicants, solid waste, plastic litters and bacterial contaminants and these toxic materials causes water pollution. Different industrial effluent that is drained in to river without treatment is the major cause of water pollution. The harmful material discharged from the industries is responsible for surface water and ground water contamination. Contaminant depends upon the nature of industries. Toxic metals enter in to water and reduced the quality of water drastically. 25% pollution is caused by the industries and is more harmful then domestic waste (Mehtabet al., 2017).
Water safety and quality are the essential key factor for development and well being .providing access to safe portable water is the most important tool in promoting health and poverty reduction. As the international authority on public health and water quality ,many organization make global effort to prevent water bone diseases this is achieve through promoting health based on regulation to government and pattern to promote effective risk management practice to communities and household. 70% the proportion of global population using a safely managing drinking water services, 2 billion people worldwide are using contaminated water with feaces (UN water REPORT, 2018). The demand for water has been increasing at a rate of about 1%per year over decades as important to function for population growth and economic. The water quality from the rivers and the well has a considerable altered every time for that reason, these water protection are generally consider to ensure its quality .surface water such as river are mainly used for multiple purpose such as domestic, water supply, agriculture , tourism recreational and human as well as economic .Many parameters influence the water quality as result of human induce factors (Andreea,2018)
Contemporary global water demand has been estimated at about 4.600km3 per year and projected to increase by 20–30% to between 5,500 and 6,000 km3 per year by 2050 UN Water Report, 2018).
Water use increases at the global level for population growth, economic development and the other factors Over the period 2017–2050, the world population is expected to increase from 7.7 billion to between 9.4 and 10.2 billion, with two thirds of the population living in cities. More than half of this anticipated growth is expected to occur in Africa (+1.3 billion), with Asia (+0.75 billion) expected to be the second largest contributor to future population growth which seriously can increase the need of safe drinking water for their survival (UN Water Report, 2018). Domestic water use, which roughly accounts for 10% of global water withdrawals, is expected to increase significantly over the 2010–2050 period in nearly all regions of the globe. In relative terms, the greatest increases in domestic demand should occur in African and Asian sub-regions where it could more than triple, and it could more than double in Central and South America. This anticipated growth can influence water quality if the water is not protected in the nearest future (UN Water Report, 2018).