Why is it harmful to discharge untreated sewage in water bodies?

What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.

Explain why , it is harmful to discharge untreated sewage into rivers , lakes or ground.

What are the harmful effects of untreated sewage?

What are disadvantages of untreated sewage?

The table shows the oxygen level, numbers of green plants and of fish in rivers flowing through four towns. Wich town is most likely to be discharging untreated sewage? {:("Oxygen level","Green plants","Fish"),("(a) high","few","many"),("(b) high","many","many"),("(c) low","few","few"),("(d) low","many","few"):}

Why CO is harmful for human beings ?

Why CO is harmful for human beings ?

Untreated domestic sewage has a low

Explain the process of sewage water treacment before it can be discharged into natural water bodies . Why is this treatment essential ?

(a) What would happen if a large volume of untreated sewage is discharged into a river? (b) In what way anaerobic sludge digestion is important in sewage treatments?