What is sewage? In which way can sewage be harmful to us?

(N/A) Sewage is the municipal waste matter that is carried away in sewers and drains. It includes both liquid and solid wastes,rich in organic matter and microbes.
Many of these microbes are pathogenic and can cause several water-borne diseases such as cholera,typhoid,and dysentery.
Sewage water is a major cause of polluting drinking water sources.
Hence,it is essential that sewage water is properly collected,treated,and disposed of to prevent environmental and health hazards.