Question

how can sewage disturb the ecological balance in lakes and rivers. [keep answer in short ]

Answer 1

The sewage of villages and cities are emptied in the rivers and lake. This sewage contains excretory materials, detergent, human waste, chemicals like plastic, DDT, and other heavy metals.These chemicals and harmful substance deplete the oxygen level in the water and affect the aquatic animals, insects, worms, plants which makes the aquatic ecosystem. So, the harmful material present in the sewage disturbs the ecosystem by affecting the members of ecosystem.

Answer 2

Sewage waters pollutes the river water . When we drink this water , we get harm . When plants take this water from soil, they dies and hence resulting in the disturbance of environmen.