The Sustainable Development Goals, also known as the SDGs, targeted at maintaining the quality of water and hygiene, reducing poverty, protecting biodiversity, and achieving peace and prosperity in the world by the year 2030 were introduced by the United Nations in 2015 . The agenda laid emphasis on the need for potable water and adequate sanitation for human survival. SDG 6, which is one of the 17 set targets of the UN to be reached by 2030, will improve accessibility to basic water and sanitation and reduce the gaps in service delivery.
Even as SDG 6 specifies 8 targets, the primary focus of this paper shall be Targets 6.1: ‘by 2030, achieve universal and equitable access to safe and affordable drinking water for all’ and Target 6.2: “by 2030, achieve access to adequate and equitable sanitation and hygiene for all and end open defecation, paying special attention to the needs of women and girls and those in vulnerable situations.”
The percentage of people in the world having access to basic sanitation increased from 59% in 2000 to 68% in 2015 . In every ten countries below 95 per cent coverage, only one is in sync with SDG 2030. Moreover, 4.5 million people globally are ill-equipped with a safely managed sanitation in 2015. A safely managed sanitation refers to the situation of bringing about the presence of an improved facility in every household where excreta are disposed safely or transported off-site for treatment.
The human right to sanitation defines sanitation as a process of collecting, transporting, treating, disposing, or reusing human excreta and associated hygiene . People deserve access to a latrine or toilet so that they would not be victims of unmanaged fecal wastes. The United Nations General Assembly (Human Rights Council) identified access to water and sanitation as human rights that are necessary for maximum comfort in life .
The basic needs of man abound in safe water, sanitation, and hygiene (WASH) for his well-being and survival . Deficiency in these vital necessities of life is detrimental to the health of many, especially children . According to the World Health Organization , about 1.8 million people in the world are estimated to die from diarrhea-related diseases, most of which were caused by the consumption of unclean water and contaminated foods.
Persons living with one ailment, or the other are even more susceptible to waterborne diseases that are ordinarily harmless to healthy individuals [8, 9]. In the less developed parts of the world, the number of people indulging in the use of undrinkable water has reduced significantly but it is just uncertain if all persons will eventually adopt a potable water . According to , 884 million people take water from unimproved water sources.
Again, the global estimate of people without access to clean water is put at 900 million . According to , the developing world of about 6 billion has almost half of her population facing the challenge of unimproved sanitation. While 70 percent of people who are deprived access to improved sanitation are found in rural areas, a corresponding proportion of about 80 per cent without access to potable water live in the area .
According to [15, 16, and 17], 9% of the world ravaging diseases can be controlled by employing the use of adequate water, sanitation, and hygiene (WASH) facilities. The most susceptible people to disease are the young people who are deprived access to water, sanitation, and hygiene facilities . The spate of death in children below the age five resulting from diarrhea disease is due to a non-compliance with WASH [18, 19].
There is no doubt, adequate WASH facilities will facilitate improvement on people’s health status and means of livelihood; but the major concern is the proliferation of these facilities in the rural areas of Nigeria [20–24]; a huge number of people in the rural parts of Nigeria are deprived access to WASH facilities . This trend has left many communities with no other choice than rivers, streams, and ponds to drink from and use for household chores  and, sorrily, to aid the act of open defecation  and this has resulted into high rate of mortality, sickness, and the proliferation of waterborne diseases [28–30].
Similarly, water which come from improved facilities such as boreholes and wells having hand pumps are quite inadequate such that young people and mothers always travel long distances to harness water. This is much time-consuming and energy-sapping as in the long run, the children’s education and the women’s livelihood are jeopardized . Again, there is a shortfall in the number of facilities needed to dispose excreta (i.e., toilet) at both household and in public places like schools , marketplaces  and hospitals .
Over the years, people have had no better choice than to defecate openly and/or in water bodies , using no soap or disinfection afterwards . Moreover, the case of shared toilet is told, where people use the toilet indiscriminately, giving no special attention to women’s needs and integrity . The failure of the government has led to the intervention of UNICEF and WHO responsible for the introduction of WASH to more than a hundred country .
Considering the substandard quality of drinking water in Nigeria, most citizens will become disposed to illnesses . Accessibility to improved water in Nigeria has become almost impossible; about 90 million Nigerians are deprived access to safe drinking water and up to 130,000 Nigerian children below the age of five die yearly from waterborne diseases. The most prevalent waterborne diseases in Nigeria are Dracunculiasis, Hepatitis, cholera, and Typhoid [39, 40].
According to [41, 42, 43], there have been incident reports about infections arising from the drinking of contaminated water in many towns. Outbreaks of waterborne diseases occur when surface water containing enteric pathogens is adopted for home and sporting purposes . In Sokoto, Shunni and Tambuwal towns, the drinking water sampled had Salmonella, E. coli, Shigella and Vibrio species that were more than WHO’s tolerance for potability .
There is paucity of data on the spread of waterborne diseases in Ondo State, especially, and in Nigeria at large. Whereas data is a major prerequisite in developing the preventive measures and the policies to hinder spread. This study, therefore, on establishing a relationship between potable water, improved sanitation, and waterborne diseases in Ondo State, Nigeria, enumerates that the spread of waterborne diseases can be prevented, as it is dependent on every household behaviour.
Impacts of Water Supply, Sanitation and Waterborne Diseases on the Economy, the Individual, and the Government
Many researchers have demonstrated a significant correspondence between non-potable water, sanitation, and maternal mortality [46, 47]. The most susceptible age group to diseases are the children below the age of five. A frequent exposure to fecal matters causes nutritional deficiencies, leading to growth stunting and mental retardment [48, 49].
According to , a significant reduction in the distance of travel to get water bears a direct impact on the prevalence of diarrhea, healthy diet, and low death rate in children under five years. This encourages better hygiene practices [51, 52, 53] and time availability for child-care, personal growth, and investment  thus encouraging the birth of healthy children.
Inadequate water available for consumption leads to dehydration which affects both mental and physical functions of the body . According to , oral rehydration salts is premised upon the use of safe drinking water. In the use of groundwater that contains deleterious elements like arsenic, 226 million people have died in more than hundred different countries .
According to , poor water and sanitation is responsible for 0.9 percent of global disability-adjusted life years (DALY) or 300,000 mortality per year. Also, 842,000 deaths worldwide are due to the prevalence of diarrhea disease  and of which 43 percent constitutes children below the age of five. According to , about 2.9 million cases of deaths were due to cholera and its prevalence in 69 countries.
Thus, when water supply and sanitation are improved, they offer comfort, safety, convenience, status, and dignity to people and optimally influences their habitat . All these are particularly beneficial to women . Although water availability does not automatically translate into women employment , it has been proven to reduce time spent on water collection by women and thus promoting gender equity .
On-slot sanitation lessens the prevalence of crimes and assault on women especially in the night or in secluded places . The adoption of improved latrines is safer as they are less susceptible to collapse and are easily accessible to small children. In India, a government programme geared towards the establishment of toilet facilities brought an 8 percent increase to pubescent-age boys and a 12 percent increase to the enrollment of younger children .