Question 16
Name two alternative arrangements for sewage disposal where there is no sewerage system.
Sewage is a complex mixture containing suspended solids, organic and inorganic impurities, nutrients, saprotrophic and disease causing bacteria and other microbes. The two alternative arrangements for sewage disposal, where there is no sewerage are as below:
(i) Septic tanks
(ii) Composting pits
To improve sanitation, low-cost onsite sewage disposal systems are being encouraged. Examples are septic tanks, chemical toilets, composting pits. Septic tanks are suitable for places where there is no sewerage system, for hospitals, isolated buildings or a cluster of 4 to 5 houses. Some organisations offer hygienic on-site human waste disposal technology. These toilets do not require scavenging. Excreta from the toilet seats flow through covered drains into a biogas plant. The biogas produced is used as a source of energy.