Contamination of water sewage is indicated by cysts of

Sewage water is purified by

Sewage water is purified by

Sewage water is purified by

State the effects of sewage contamination of surface water. What steps should be taken to prevent sewage pollution.

State the effects of sewage contamination of surface water . When steps should be taken to prevent seqage pollution.

The presence of a particular group of bacteria in water bodies indicates contamination. Identify the group.