Correct Answer - Option 4 : 1, 2, 3 and 4
Pit Privy Latrine:
The pit privy consists of a hand-dug hole in the ground covered with either a squatting plate or a slab provided with riser and seat. A superstructure or house is then built around it.
The function of the pit is to isolate and store human excrete in such a way that no harmful bacteria can be carried there from to a new host.
The depth is usually about 5 m but some pits have been due to a depth of 4 m to 8 m in soils which are very stable.
Bore- Hole Latrine:
The borehole latrine is an (emergency) excreta disposal system where a borehole (typically 5-10 m deep, 40 cm in diameter) is combined with a slab and a superstructure. It is an alternative to pit or trench latrines where ground conditions allow it and tools and labour is immediately available locally. A lid on the drop hole keeps light out of the pit and helps to stop flies and odours entering the toilet's superstructure.
Aqua-privy:
An aqua-privy has a watertight tank immediately under the latrine floor. Excreta drop directly into the tank through a pipe. The bottom of the pipe is submerged in the liquid in the tank, forming a water seal to prevent escape of flies, mosquitoes and smell. The tank functions like a septic tank. Effluent infiltrates into the ground through a soak pit.
