Reuse of faeces and urine from ecological sanitation
Practical Action
This technical brief briefly explains when risks are associated with re-use and who is at risk
during each stage. There is some explanation of the treatment methods for the three types of
product i.e. faeces, urine and combined urine and faeces. Finally some practical guidelines
are given on how to apply excreta and how to do this safely.
Stages of exposure
There are essentially six phases in the re-use of urine and faeces, table 1 shows these phases
and who is at risk during each phase. It also suggests some possible mitigation procedures at
various stages, some of which will be discussed in more detail later.
Table 1 – Major exposure points when reusing excreta [Adapted from: WHO, 2006]
Risk Activity
Exposure Route Groups at Risk
Mitigation
Emptying collection Contact
Entrepreneurs
Protective clothing
vessel/chamber
Residents
Training
Local community Optimise on-site treatment
Transportation
Secondary (off-site)
treatment
Contact
Spread through
equipment
Contact
Vectors
Entrepreneurs
Local community
Workers
Nearby
community
Avoid spillage
Clean equipment before
using it on other material
Avoid spillage
Efficient treatment
Protective clothing
Restrict access
Application
Contact
Entrepreneurs
Reduce vector propagation
Work material into soil
Inhalation
Crops, harvest,
processing and sale
Consumption
Handling
Farmers
Local community
Consumers
Workers
Vendors
Restrict access to field if
quality is not guaranteed
Protective clothing for
workers
Allow one month between
application and harvest
Food consumed raw is
highest risk
Protective clothing
Consumption
Consumption
Consumers
Provide water for cleaning
Practising good hygiene
Cooking thoroughly
Many practical steps to ensure the excreta is used safely are discussed below, these focus
mostly on the application, harvesting and consumption of crops. One of the simplest methods
to mitigate all risks is to ensure thorough primary treatment (on-site) takes place. The earlier
in the sequence of events treatment takes place the better, as risks will be minimised further
down the line. The methods used to kill pathogens will now be discussed in order to clarify
the factors affecting pathogen survival in excreta.
Factors contributing to pathogen die off
The factors listed in table 2 cause pathogens within excreta to die off. One or a combination
of these will render faeces safe, note that urine does not contain a high level of pathogens
and a certain level of storage will render it completely safe (see below).
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