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[[Image:Icon_fill_and_cover_arborloo.png |right|95px80px]]
'''When a pit is full, it can simply be filled with soil and covered. Although there is no benefit recovered, the full pit poses no immediate health risk, and with time, the contents will degrade naturally. Alternatively, the ‘Arborloo’ is a shallow pit that is filled with excreta and soil/ash and then covered with soil; a tree planted on top will grow vigorously in the nutrient-rich pit.'''
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! width="50%" style="background:#efefef;" | Advantages
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| valign="top" |- Simple technique for all users. <br>
===Adequacy===
Filling and covering pits is an adequate solution when emptying is not possible and when there is space to continuously re-dig and fill pits. The Arborloo can be applied in rural, peri-urban, and denser areas if space is available. Planting a tree in the abandoned pit is a good way to reforest an area, provide a sustainable source of fresh fruit and prevent people from falling into old pit sites.
===Health Aspects/Acceptance===
There is a minimal risk of infection if the pit is properly covered and clearly marked. It may be preferable to cover the pit and plant a tree rather than have the pit emptied, especially if there is no appropriate technology available for treating the faecal sludge. Users do not come in contact with the faecal material and thus there is a very low risk of pathogen transmission. Demonstration projects that allow community members to participate are useful ways of showing both the ease of the system, it’s inoffensive nature, and the nutrient value of composted excreta.
===Maintenance===
A cup of soil and/or ash should be added to the pit after each defecation and leaves should be added periodically. Also, the contents of the pit should be periodically levelled to prevent a coneshape from forming in the middle of the pit. There is little maintenance associated with a closed pit other than taking care of the tree or plant. If a tree is planted in the abandoned pit, it should be watered regularly. A small-fence should be constructed with sticks and sacks around the sapling to protect it from animals.
===References===
* Morgan, P. (2007). [http://www.ecosanres.org/toilets_that_make_compost.htm Toilets that make compost]. Stockholm Environment Institute, Stockholm, Sweden. pp 81–90.
* NWP (2006). [http://www.nwp.nl/_docs/publicaties/Smart_Sanitation_Solutions_EN_2006.pdf Smart Sanitation Solutions. Examples of innovative, low-cost technologies for toilets, collection, transportation, treatment and use of sanitation products.] Netherlands Water Partnership, The Netherlands. pp 51.
===Acknowledgements===
{{:Acknowledgements Sanitation}}
