Different Methods of domestic waste water disposal include (Systems of Sanitation)
1) CONSERVENCY SYSTEM
2) WATER CARRIAGE SYSTEM
Sometimes the system is also called as dry system. This is out of date system but is prevailing in small towns and villages. Various types of refuse and storm water are collected conveyed and disposed of separately. Garbage is collected in dustbins placed along the roads from where it is conveyed by trucks ones or twice a day to the point of disposal. all the non combustible portion of garbage such as sand dust clay etc are used for filling the low level areas to reclaim land for the future development of the town. The combustible portion of the garbage is burnt. The decaying matters are dried and disposed of by burning or the manufacture of manure.
Human excreta are collected separately in conservancy latrines. The liquid and semi liquid wastes are collected separately after removal of night soil it is taken outside the town in trucks and buried in trenches. After 2-3 years the buried night soil is converted into excellent manure. In conservancy system sullage and storm water are carried separately in closed drains to the po int of disposal where they are allowed to mix with river water without treatment.
2. WATER CARRIAGE SYSTEM
With development and advancement of the cities urgent need was felt to replace conservancy system with some more improved type of system in which human agency should not be used for the collection and conveyance of sewage .After large number of experiments it was found that the water is the only cheapest substance which can be easily used for the collection and conveyance of sewage. As in this system water is the main substance therefore it is called as WATER CARRIAGE SYSTEM.
In this system the excremental matter is mixed up in large quantity of water their ars taken out from the city through properly designed sewerage systems, where they are disposed of after necessary treatment in a satisfactory manner.
The sewages so formed in water carriage system consist of 99.9% of water and .1% solids .All these solids remain in suspension and do not changes the specific gravity of water therefore all the hydraulic formulae can be directly used in the design of sewerage system and treatment plants.
Very cheap in initial cost.
Due to foul smells from the latrines, they are to be constructed away from living room so building cannot be constructed as compact units.
The aesthetic appearance of the city cannot be improved
For burial of excremental matter large area is required.
Excreta is not removed immediately hence its decomposition starts before removal,
This system is fully depended on human agency .In case of strike by the sweepers; there is danger of insanitary conditions in
WATER CARRIAGE SYSTEM
It involves high initial cost.
As there is no foul smell latrines remain clean and neat and hence are constructed with rooms, therefore buildings may be compact.
Good aesthetic appearance of city can be obtained.
Less area is required as compared to conservancy system.
Excreta are removed immediately with water, no problem of foul smell or hygienic trouble.
As no human agency is involved in this system ,there is no such problem as in case of conservancy system