Newsletter and Technical Publications
<International Source Book On Environmentally Sound Technologies
for Wastewater and Stormwater Management>
4.1.3 Pour flush toilet
A pour flush toilet (Figure 2.17) has a water seal. The problems associated
with odour and insects are avoided by having the water seal.
Excreta deposited in the latrine pan is flushed by pouring 2 to 3 L of water
into it. The mixture is directed into a pit in the same way as for a pit
latrine. The processes of biodegradation of the organic wastes in the pit are
exactly the same. More water percolates through the soil surrounding the pit,
and the potential for groundwater pollution is higher. A pour flush toilet with
a pit is therefore not suitable when groundwater table is close to the surface.
Sludge has to be regularly emptied from the pit. The use of two
adjoining pits alternately enables the sludge in a full pit to undergo further
decomposition while the other pit is being used, and enables manual sludge
emptying after further sludge decomposition.
With the use of the pit latrine, composting toilet and pour
flush latrine, greywater (sullage) has to be separately treated. Greywater can
be reused directly or after treatment (see Section on Wastewater Reuse 2 (6)).
Disposal of greywater on-site is by use of a leach pit or trench (See below
under Septic tank). Limitations of disposal of greywater by leach pit or trench
are similar to those applicable to septic tank.