Types of toilet and their suitability
Practical Action
Ecological Sanitation Latrines
Ecological sanitation (ecosan) latrines have been developed employing the concept that human
waste contains nutrients that should be returned to the soil and used to grow more food. There
are different types of toilet, which treat the waste to some extent prior to using the by-product to
increase fertility of land. The types of toilet can be split into dehydrating and composting types
with urine diversion often being employed to make the most of the nutrients available.
More information can be found in the Practical Action technical notes ‘Ecological Sanitation: A
Concept’ and ‘Re-use of Faeces and Urine from Ecological Sanitation’.
Advantages
Recognises urine and faeces as useful by-
products which can provide users with a
cheap fertiliser and soil conditioner
Reduces pollution problems associated with
some forms of wastewater disposal
Disadvantages
Require appropriate training of users to
ensure the systems are operated correctly and
people not put at risk
Typically systems do not accept a wide
variety of anal cleansing materials
More expensive than simpler types of latrine
Aqua-Privy
An aqua-privy functions in a similar
manner to a septic tank whilst avoiding the
need for a consistent water supply to
operate a flush toilet. The water will drain
off the top and the sludge needs to be
emptied on a regular basis. An advantage
of the aqua privy is that it reduces odours.
However, regular emptying could become
an onerous requirement.
Figure 5: An aqua privy
(Source: Harvey et al, 2002)
Advantages
Does not require a piped water supply as a user
can defecate directly into the tank
It is a cheaper form of a septic tank
Disadvantages
The system can fail to reduce smells if the
water seal is not maintained
Water must be available and plentiful
Requires emptying
Permeable land is needed to drain effluent
Septic Tanks
A septic tank is a water tight tank that typically receives waste from a flush toilet. They are
useful in areas with a high water table (due to the sealed nature contamination of the water table
is less likely) and when a reliable water supply is present. The system provides some level of
treatment to the waste through the separation of solids.
The tank should be emptied routinely to ensure effluent does not contain unsafe levels of
pathogens and that the sludge does not occupy too high a proportion of the tank. Ideally the
effluent from the septic tank should be attached to a sewerage system, however in many cases
the outlet is connected to a drainage field (if this is the case the ground should be permeable
enough to prevent ponding). This liquid effluent will not be completely clear of contaminants
hence the requirement to avoid ponding.
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