(a) The sources of water are: Lakes, Rains, Ponds, Wells and Glaciers.
(b) The river Ganga is polluted. The water of river Ganga is turned into a dirty watered rain by the discharge of untreated sewage and industrial wastes.
The pollution of river Ganga is also caused by human activities like, Bathing, washing of clothes, immersion of ashes of the dead and dumping of unburnt corpses into its water. The industries also discharge effluents into the river water.