Waste Management - I — Geography STD 10 — Question

(i) Sewage contains harmful microorganisms such as bacteria, viruses and protozoa which cause various diseases like cholera, jaundice, dysentery etc.
(ii) Direct contact with sewage or surfaces contaminated by sewage can result in illnesses and also skin diseases.
(iii) That is why Sewage water must be treated before releasing in river.