Question

Sewage should be treated before discharging in river

Answer 1

Sewage contains pollutants that can harm us, as well as wildlife. Feces contain e-coli and other bacteria which lead to illness. Chemicals are a problem that way too, and can lead to death.

In addition, towns along a river pump their fresh water from that river somewhere up the river from town, and discharge their wastewater down river from town. The next town down the river does the same. If none of these towns treated their sewage no one down the river would have access to clean water. Since the Earth has become so crowded with people, sewage treatment has helped clean water faster and now some common forms of disease have become rare.