This question was popular among the candidates. 

This candidates  performed averagely in the question.  Some of the candidates confused sources of water pollution with causes of water pollution.  The sources of water pollution are:

            -           pesticides
-           herbicides
-           industrial waste discharge
-           heat  from power and industrial plants
-           use of chemical fertilizers
-           flooding
-           acid rain
-           city drainage
-           untreated sewage
-           cloud seeding
-           mining
-           discharge from ships
-           fishing with chemicals
-           dumping of refuse in water
-           erosion materials
-           volcanic eruption
-           oil spillage
-           leakage from landfills
-           washing of clothes in rivers with detergent   
-           animal dung in rivers
Most candidates were able to highlight the measures that could be taken to control water pollution.