Water Pollution In Sub-Saharan Africa

Water supply which is easily available, potable and affordable is a prerequisite for good hygiene, sanitation and is central to the general welfare of all living things. The World Health Organisation (WHO) estimated 1.8 million deaths each year due to lack of access to safe water, sanitation and hygiene. However, about 784 million people worldwide still need to gain access to safe drinking water (UN, 2008). The United Nations Environmental Programme (UNEP) estimates show that 250 million people in Africa will be at risk of water stress, less than 1700 m3 of water available per person per year by 2020 and up to 500 million by 2050 (Falkenmark etal., 1989). Sub-Saharan Africa is making the slowest progress in meeting the MDGs target with one-third

1.0: Comparison of water sources in terns of Turbidity

3.4 Nitrate

The borehole samples from Buipe town had mean nitrate concentration of 4.5 mg/l and3.30 mg/l in the wet and dry seasons respectively. There was significant difference (2.52, P<0.05) of pH was recorded between river water from Buipe and Yapei in the wet season. The relatively low pH of Black Volta at Buipe may be due to high concentration of dissolved organic loads (Rickey etal., 1990). The low pH of Black Volta at Buipe might have been caused by high amounts of dissolved sediments.

The relatively high mean conductivity in the wet season can be adduced to run-offs that carried dissolved fertilizer, pesticides, herbicides and other particles from cultivated fields into the rivers. The relatively low mean conductivity may be due to the absence of run-offs in the dry season.

The high turbidity of the river samples from Buipe and Yapei may have been caused by higher flow rates during rainfalls that might have carried sediments and other materials into the rivers. The low mean turbidity of the river samples may be due to the absence of run-offs and the recession in flow level in the dry

Further, the low conductivity of fresh rainwater is validated by frequent rainfalls combined with low temperature during the sampling period (wet season). This is probably due to low levels of particulates such as smoke, dust, and soot suspended in the atmosphere which dissolved in the rain droplets as it falls from the sky. This may also be related to the presence of particles of clay, organic components and other microscopic substances (Ovrawah and Hymone, 2001). In addition, the low turbidity in the rainwater samples can be associated with frequent rainfalls during the sampling period. Appiah (2008) studied the physicochemical analysis of roof run-off established that turbidity is affected by dry spell, and the longer the span of continuous rainfalls, the lower is the