Observation

This was a very popular question answered by majority of the candidates and they performed very well in the question.

(a) Meaning of water pollution
It is the release of substances into water bodies in quantities that make it unfit for use by man, animals and other living organisms.

(b) Causes of water pollution
- volcanic eruption
- discharge of effluents from ships/vessels
- acid rain
- discharge of untreated sewage
- use of bombs and other military facilities
- oil spillage
- unregulated mineral workings
- fishing with chemicals
- use of detergents in water bodies
- use of chemical fertilizers
- industrial wastes
- use of same water source by both animals and man
- discharge of silt and weathered materials into water bodies (flooding)

(c) Effects of water pollution on the environment
- leads to death of aquatic animals and man>]
- reduces recreational values of water
- causes waterborne diseases e.g. cholera
- encourages growth of sea weeds and algae that impedes water transport
- destroys safe water for industrial use
- produces bad odour
- money and time is lost during the purification of water for safe use
- causes displacement of settlements (migration)
- depletion/extinction of aquatic organisms
- disruption of aquatic ecosystem
- there is shortage of safe water for domestic use
- unemployment among fishermen

(d) Measures for controlling water pollution
- treatment of industrial waste
- treatment of sewage before discharging in to rivers
- monitoring ships and pipeline against leakages
- reclamation of spilled oil
- change from chemical to organic fertilizers
- good fishing practices
- public education
- reduction of military conflicts through dialogues and mediation
- enforcement of legislations on water pollution
- provision of alternative sources of water for farm animals
- provision of public utilities/incinerators/toilets
- conduct of environmental impact assessment before mines are opened
- recycling of wastes