According to the Environmental Pollution Center, Water pollution is the presence in groundwater of toxic chemicals and biological agents that exceed what is naturally found in the water and may pose a threat to human health and the environment.

Lake Victoria, Uganda, the largest lake in Africa, faces numerous environmental issues including water pollution and its subsequent problems like biodiversity and habitat loss. Its water pollutants come from different sources, one of which is the Nakivubo channel. 

Nakivubo channel is a storm water channel that starts at the foothills of Makerere hill and passes through Makerere Kivulu slum, to three busy markets and to the Kampala Industrial Area and then discharges its water at Murchison Bay in Lake Victoria, Uganda.

In Makerere Kivulu slum, pit latrines are emptied in the channel. The human excreta introduced in the channel highly contaminates the water which causes air pollution and a high risk of waterborne diseases to surrounding communities.

Plastic waste and other kinds of garbage are dumped in the channel that causes blockage and stagnation of water, which further creates a breeding site for disease-causing vectors like mosquitoes.

During the rainy season, runoff from the slum, markets and industrial areas adds heavy metals, nitrogen, chemical waste and other pollutants to the channel water, increasing it's toxicity.

Consequently, Lake Victoria has become suffocated by plastic, garbage, chemicals and their toxicity. All these cause the lake's equivalent of a slow death, that is evident in fish kills and poor water quality.

References

A study of the degree of Pollution in

Nakivubo Channel, Kampala, Uganda.

http://www.bioline.org.br/request?ja08034

What is Water Pollution?

https://www.environmentalpollutioncenters.org/water/

Environmental Education and Lake Victoria

https://wwf.panda.org/wwf_offices/regional_office_for_africa/our_solutions/projects/?uProjectID=9F0736