Revision history [back]
If these are domestic latrines and there is potential for the superstructure and slab to be moved then how about using shallow pits and digging new pits say every two years and then moving the superstructure over these and covering the pit with soil? However, ideally the pit should be lined for at least the top 0.5m to prevent cave-ins and entry of rodents and flies. Diverting any stormwater flows away from the pit by slightly raising it above the ground will help prevent surface water washing into the pit. It is also important to stop any rain flowing off the roof from eroding the soil and flowing into the pit.
An alternative is to use two shallow pits serving the same superstructure since this means that the costs of the lining are minimum and the pits can be reused. Each pit should have a capacity of two- year’s storage of faeces. One pit is used until it is full then the drop-hole to that pit is sealed whilst the other is used. After two years that one will be full and the contents of the first will be safe to remove and spread on the gardens/fields. Then the drop hole to the freshly-emptied pit can be opened and it can be re-used. Although the contents of the second pit are like rich humus the problem is that some people my culturally still not be willing to handle them.