Authors : N. Banadda, G. Nakawooya, C. Nambooze, S. Natukunda, M.D. Nakibuuka, D. Luswata, F. Ayaa, U.G. Wali and I. Nhapi
Abstract: The natural resources of the Lake Victoria basin support livelihoods of over 30 million people. Although, a number of researchers have studied, the effects of non point source pollution on water quality in Lake Victoria basin such published studies are often carried out for short periods of 6 months or less due constraints in resources such as time and funds, etc. The consequence of this is that indicative parameters are instantaneously measured or monitored as a basis for generic conclusions and/or recommendations that cannot be supported. In order to positively influence policy and policy makers, credible data measured over a realistically long period is needed. In this study, Non-Point Source pollution (NPS) was monitored, measured and characterized with a view of understanding bioaccumulation of Lead (Pb) in fish and nutrient pollutant loading in the lake for a period of 4 years and 6 months (January, 2007 to June, 2011). The study was conducted at Ggaba landing site, Makindye division and Kampala district. All samples were analyzed for nutrients, namely, ammonia, nitrite, nitrate and phosphate using standard methods for Examination of Water and Wastewater. A total of 520 samples were collected at Ggaba landing site in Uganda and were analyzed for nutrients, namely, Ammonia, Nitrite, Nitrate and Phosphate. In addition, portable meters were used to measure Total Dissolved Solids (TDS) and Dissolved Oxygen (DO) instantaneously at point of sample collection. Within the lake, samples were taken at for horizontal transects of 10 m interval over a distance of 50 m from the shore where surface runoff was released. At each 10 m sampling point, three samples were drawn at vertical distances of 0.5, 1.0 and 1.5 m from water surface using a hand pump with graduated delivery pipe. In general, the results showed that nutrient concentrations were highest at the shore and water surface. The 2010 yearly average concentration of 3.8 mg L-1 phosphate was the highest followed by ammonia at 2.1 mg L-1, nitrite at 1.11 mg L-1 and nitrates at 0.38 mg L-1. Interestingly, the nutrient loading has doubled during the last 4 years. In conclusion, the traditional habit of drawing water on the surface especially between distance 0 and 0.5 m exposes water users to the highest pollution loads while Pb levels of exceed maximum daily permissible Pb uptake in water.
N. Banadda, G. Nakawooya, C. Nambooze, S. Natukunda, M.D. Nakibuuka, D. Luswata, F. Ayaa, U.G. Wali and I. Nhapi, 2011. Pollution of Lake Victoria: What Is Next?. Research Journal of Soil and Water Management, 2: 19-28.