Question

major sources of sewage

Answer 1

the important sources of water pollution (sewage) are: (i) Domestic effluents and sewage, (ii) Industrial effluents, (iii) Agricultural effluents, (iv) Radioactive wastes, (v) Thermal pollution, and (vi) Oil pollution.

Answer 2

sources of sewage are:
Domestic effulents
industrial effulents
agricultural effluents
radioactive wastes
thermal pollution
oil pollution