Fuel Fertiliser and Calcutta Sewage-Sludge

Preliminary-In any sewage treatment work final disposal of sludge produced from the plant is the most difficult part and requires most careful consideration and planning. It is specially so in the case of a city like Calcutta the growth of which has been phenomenal. According to the Census Report of 1931 the population was 1.2 millions, in 1941 it rose to 2.1 millions and if census were to be taken now it would perhaps show a population of 3.6 millions including the members of the allied forces now present in the city. The problem, therefore, takes on a vast magnitude as large quantities of sewage-sludge would have to be dealt with daily and solids disposed of expeditiously without creating any nuisance.