VPE 511: Environment and Environmental Hygiene (2+1)

METHODS OF SEWAGE DISPOSAL

Conservancy Methods

• It is now practically confined to rural areas where the water supply is inadequate for the installation of a water carriage system. The simplest method of disposing of human excreta is burial in the soil. Since proper disposal is of some importance owing to the risk of flies carrying pathogenic bacteria such as typhoid bacilli from infected excreta to the milk.
• The human excreta should be buried in shallow trenches and covered with top soil without chemicals since disinfectants and antiseptics merely retard putrefaction. The faeces decompose without causing any harm. The place chosen for the ultimate deposition should be distant from the house and not near a well.

Water Carriage System

• In this system the private drains from dwelling houses and other buildings empty into public sewers, which convey the sewage to a purification works where it is treated so as to render the resulting effluent suitable for ultimate disposal into the sea or into rivers and streams.