• Brainly User
•Untreated sewage and chemicals - This affects the aquatic life as well as the soil's fertility.
•Religious and social practices - People often dump carcasses in the rivers,take dips in the rivers,bath in the rivers and put flowers and throw away the ashes of dead into the water.
•Agricultural practices - Farmer's over use pesticides,which percolates into the soil, and ultimately the ground water is polluted.
•Frequent floods - The floods,wash away the solid wastes into rivers.
•Industries - Industries let out heavy metals.Toxic substances are let into the rivers without treating.