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Arborloo

Compiled by:
Eawag (Swiss Federal Institute of Aquatic Science and Technology), Robert Gensch (Xavier University), Niels Sacher (Xavier University)
Adapted from:
TILLEY, E.; ULRICH, L.; LUETHI, C.; REYMOND, P.; ZURBRUEGG, C. (2014)

Executive Summary

To decommission a pit, it can simply be filled with soil and covered. Although there is no received benefit, the full pit poses no immediate health risk and the contents will degrade naturally over time. 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 of the nutrient-rich pit will vigorously grow. The pit (approximately 1.0 to 1.5 m deep) and the toilet superstructure (consisting of a ring beam, slab and structure) are both temporary and move from one site to the next at 6 to 12 month intervals while old pits are covered and the trees are growing.

In Out

Faecal Sludge, Faeces, Excreta, Organic Solid Waste

Compost / Biosolids

Introduction

When a single pit or a single VIP is full and cannot be emptied, "fill and cover", i.e., filling the remainder of the pit and covering it is an option, albeit one with limited benefits to the environment and the user.

Low-cost Arborloo with separate collection of urine in EcoPees SuSanA on Flickr (2010)

Low-cost Arborloo with separate collection of urine in EcoPees (urinal made out of recycled plastic containers). Designed and constructed by WAND Foundation (www.wandphils.org). Source: SuSanA (2009)

The Arborloo is a shallow pit on which a tree can be planted after it is full, while the toilet superstructure, ring beam and slab are moved to a new pit in an endless cycle (usually moved once every 6 to 12 months). The pit should be about 1 to 1.5 m deep and should not be lined to not limit the space for the tree to grow. Before the Arborloo is used, a layer of leaves is put on the bottom of the empty pit. A cup of soil, ash or a mixture of the two should be dumped into the pit to cover excreta after each defecation. If they are available, leaves can also occasionally be added to improve the porosity and air content of the pile. When the pit is full (usually every 6 to 12 months), the top 15 cm is filled with soil and a tree is planted. Banana, papaya and guava trees (among many) have all proven to be successful by using the nutrients derived from the compost formed from excreta. When soil, wood ash and leaves are regularly added, the conversion into compost takes place at a faster rate compared to excreta to which nothing has been added. The daily addition of soil and ash also helps to reduce flies and smells. But if ash or leaves are not available, already the addition of soil alone can help (MORGAN 2007).

     R. Gensch)

Arborloo in a rural area of Misamis Oriental (Philippines). Source: R. Gensch    

A young tree is planted in the composting soil. The growing roots of the young tree first invade the topsoil layer, whilst the excreta below are turning into humus. If the trees are very young it may be better to plant them in buckets, pots or larger containers first, so that the root system can grow more extensively and become more resilient before transplanting into the pit. It is also often better to allow the pit contents to compost for a while, top up with soil again before planting the tree. Other plants (e.g. tomatoes or pumpkins) can also be planted. A small-fence constructed with sticks and stacks around the sapling helps to protect it from animals.

Design Considerations

An Arborloo is only an option if the site is suitable for a tree to grow. Therefore, when selecting the pit location, users should already take the space and site conditions required for a new tree into account (e.g., distance to houses).

A shallow pit, about 1 m deep, is needed for an Arborloo. It should not be lined as any lining would prevent the tree or plant from properly growing.

A tree should not be planted, however, directly in the raw excreta. It should be planted in the soil on top of the pit, allowing its roots to penetrate the pit contents as it grows. It may be best to wait for the rainy season before planting it if water is scarce.

             TILLEY et al. 2014

Schematic of the two steps. Source: TILLEY et al. (2014)            

Health Aspects/Acceptance

There is minimal risk of infection if the pit is properly covered and clearly marked. It may be preferable to cover the pit and to plant a tree rather than emptying it, especially if there is no appropriate technology available to remove and treat the faecal sludge.

Users do not come in contact with the faecal material and, thus, there is a very low risk of pathogen transmission.

Arborloo demonstration projects that allow for the participation of community members are useful ways to display the ease of the system, its inoffensive nature, and the nutrient value of human excreta.

Operation & Maintenance

A cup of soil and/or ash should be added to the pit after each defecation and leaves should be periodically added. Also, the contents of the pit should be periodically levelled to prevent a cone shape from forming in the middle.

There is little maintenance associated with a closed pit other than taking care of the tree or plant. Trees planted in abandoned pits should be regularly watered. A small fence of sticks and sacks should be constructed around the sapling to protect it from animals.

Applicability

Filling and covering a pit is an adequate solution when emptying is not possible and when there is space to continuously dig new pits.

The Arborloo can be applied in rural, peri-urban, and even denser areas if enough 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.

Other plants such as tomatoes and pumpkins can also be planted on top of the pit if trees are not available.

Depending on the local conditions, however, the content of a covered pit or Arborloo could contaminate groundwater resources until it is entirely decomposed.

Advantages

  • Simple technique for all users
  • Low costs
  • Low risk of pathogen transmission
  • May encourage income generation (tree planting and fruit production)

Disadvantages

  • New pit must be dug; the old pit cannot be re-used
  • Covering a pit or planting a tree does not eliminate the risk of groundwater contamination
  • Relatively labour intensive
  • Not suitable with a high groundwater table
  • Is only possible where there is enough space

References Library

HERBERT, P. (2010): Rapid Assessment of CRS Experience With Arborloos in East Africa. Baltimore: Catholic Relief Service. URL [Accessed: 03.01.2011]. PDF

MORGAN, P. (2004): The Usefulness of Urine. In: Morgan, P. (2014): An Ecological Approach to Sanitation in Africa. A Compilation of Experiences. Harare. URL [Accessed: 04.04.2014]. PDF

MORGAN, P.; EcoSanRes (Editor) (2007): Toilets That Make Compost . Stockholm: Stockholm Environment Institute. PDF

See document in FRENCH

MORGAN, P.; EcoSanRes (Editor) (2009): Ecological Toilets. (pdf presentation). Stockholm: Stockholm Environment Institute. PDF

NWP (Editor) (2006): Smart Sanitation Solutions. Examples of innovative, low-cost technologies for toilets, collection, transportation, treatment and use of sanitation products. (= Smart water solutions). Amsterdam: Netherlands Water Partnership (NWP). URL [Accessed: 13.04.2010]. PDF

SUSANA (2009): Low-cost Arborloo with separate collection of urine in EcoPees. SuSanA on Flickr. SuSanA. URL [Accessed: 09.06.2011].

TILLEY, E.; ULRICH, L.; LUETHI, C.; REYMOND, P.; ZURBRUEGG, C. (2014): Compendium of Sanitation Systems and Technologies. 2nd Revised Edition. Duebendorf, Switzerland: Swiss Federal Institute of Aquatic Science and Technology (Eawag). URL [Accessed: 28.07.2014]. PDF

Further Readings Library

Reference icon

MORGAN, P. (2004): The Arborloo Book. (pdf presentation). Stockholm: Stockholm Environment Institute. PDF

This booklet describes how to construct an arborloo toilet, which is both low cost and easy to make.


Reference icon

MORGAN, P.; EcoSanRes (Editor) (2009): Ecological Toilets. (pdf presentation). Stockholm: Stockholm Environment Institute. PDF

This book describes how to construct Arborloo toilets and how it can be upgraded to VIPs at a later stage.


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MORGAN, P. (2004): The Arborloo and growing trees. (pdf presentation). Stockholm: Stockholm Environment Institute. PDF

This extract describes how to create a low-cost and well functioning arborloo and contains lots of information on how to plant trees in the closed pit.


Reference icon

MORGAN, P.; EcoSanRes (Editor) (2007): Toilets That Make Compost . Stockholm: Stockholm Environment Institute. PDF

This book describes in an easy-to-understand and picture-based way how to construct three different low cost sanitation solutions, namely arborloos, fossa alterna and urine diversion toilets.

See document in FRENCH


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EcoSanRes (Editor) (2008): Toilets That Make Compost. Factsheet. (pdf presentation). (= EcoSanRes Factsheet 13). Stockholm: Stockholm Environment Institute. PDF

This information sheet summarises the Peter Morgan publication under the same name on two pages. It describes three types of simple and affordable composting toilets: Two types of shallow pit toilets (arborloo) and the urine diverting toilet.


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EcoSanRes (Editor) (2008): An Ecological Approach to Sanitation in Africa: A Compilation of Experiences. (= EcoSanRes Factsheet 12). Stockholm: Stockholm Environment Institute (SEI). PDF

This factsheet provides information and experiences of simple pit toilet and twin pit toilet. It also contains knowledge about upgrading technologies, hygiene and usage of faeces as fertilizer.


Reference icon

TILLEY, E.; ULRICH, L.; LUETHI, C.; REYMOND, P.; ZURBRUEGG, C. (2014): Compendium of Sanitation Systems and Technologies. 2nd Revised Edition. Duebendorf, Switzerland: Swiss Federal Institute of Aquatic Science and Technology (Eawag). URL [Accessed: 28.07.2014]. PDF

This compendium gives a systematic overview on different sanitation systems and technologies and describes a wide range of available low-cost sanitation technologies.


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GENSCH, R.; MISO, A.; ITCHON, G.; SAYRE, E. (2010): Low-Cost Sustainable Sanitation Solutions for Mindanao and the Philippines. A Practical Construction Field Guide. Cagayan de Oro City: Xavier University. URL [Accessed: 06.10.2011]. PDF

After a brief introductory chapter on the Philippine sanitation situation and basic principles of sustainable sanitation, the manual focuses on the introduction of different low-cost sanitation solutions comprising the arborloo toilet, the 1-chamber and 2-chamber UDDT, hanging UDDTs, and the ecopee urinal. Each technology is briefly described by giving general information on how it works, operation and maintenance requirements, reuse or safe disposal options, and in which setting this technology might be appropriate. In addition, a picture-based guide on how to construct each technology is provided as well as the necessary technical drawings and rough cost estimates based on current prices. Since a sanitation system does not end with the toilet itself, the last chapter also provides information on the overall management of the system including collection, transport, treatment, and final reuse of urine, feces and composting products in agriculture.


Reference icon

TOUBKISS, J. (2010): How to Manage Public Toilets and Showers. (= Six Methodological Guides for a Water and Sanitation Services' Development Strategy, 5). Cotonou and Paris: Partenariat pour le Développement Municipal (PDM) and Programme Solidarité Eau (pS-Eau). URL [Accessed: 19.10.2011]. PDF

The purpose of this decision-making aid is to provide practical advice and recommendations for managing toilet blocks situated in public places. It is primarily aimed at local decision-makers in developing countries and at their partners (project planners and managers).

See document in FRENCH


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NATURE (Editor); MORGAN, P.; OTTERPOHL, R.; PARAMASIVAN, S.; HARRINGTON, E. (2012): Ecodesign: The Bottom Line. In: Nature: International Weekly Journal of Science 486, 186-189. URL [Accessed: 19.06.2012]. PDF

There is no single design solution to sanitation. But there are universal principles for systematically and safely detoxifying human excreta, without contaminating, wasting or even using water. Ecological sanitation design — which is focused on sustainability through reuse and recycling — offers workable solutions that are gaining footholds around the world, as Nature explores on the following pages through the work of Peter Morgan in Zimbabwe, Ralf Otterpohl and his team in Germany, Shunmuga Paramasivan in India, and Ed Harrington and his colleagues in California.


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MORGAN, P. (2011): Trees as recyclers of nutrients present in human excreta. (= Main tree report). Zimbabwe: Aquamor Pvt Ltd.. URL [Accessed: 19.06.2013]. PDF

his report clearly indicates that trees of various types can benefit greatly from the nutrients derived from human excreta and the methods of transferring the nutrients can vary somewhat. These vary from direct uptake from an unlined pit, a lined pit, by various methods of urine application and also from the seepage from soakaways linked to septic tanks of various types.


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MORGAN, P. (2010): Methods of Using "Toilet Compost" in Agriculture. Stockholm : Ecological Sanitation Research (EcoSanRes), Stockholm Environment Institute (SEI). URL [Accessed: 20.06.2013]. PDF

This document gives a simple overview over toilet compost, its preparation and fields of application.


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MORGAN, P. (2004): The Usefulness of Urine. In: Morgan, P. (2014): An Ecological Approach to Sanitation in Africa. A Compilation of Experiences. Harare. URL [Accessed: 04.04.2014]. PDF

The chapter "the usefulness of urine" is about different methods of collecting urine, storage, uses of urine in agriculture and gives various examples of using urine to enhance vegetable production in containers and on fields


Case Studies Library

Reference icon

HERBERT, P. (2010): Rapid Assessment of CRS Experience With Arborloos in East Africa. Baltimore: Catholic Relief Service. URL [Accessed: 03.01.2011]. PDF

This rapid assessment reviewed sanitation activities by Catholic Relief Services in East Africa, in particular the promotion of the Arborloo – an innovative latrine designed to help achieve sustainable and scalable sanitation improvements in rural Ethiopia, South Sudan, Kenya and Uganda. The assessment explored the factors affecting Arborloo acceptance and sustainability, the scope and approaches for scaling up the latrine in these countries and in Tanzania, as well as opportunities to foster links between community and school sanitation.


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BRESLIN, N. (2000): Ecosan in Niassa. (= Water Aid Mozambique Report No. 1). Maputo: Water Aid Mocaambique. PDF

Water Aid (Moçambique) has spent about one year supporting the Government’s efforts to revive a sanitation programme in the Niassa Province, northern Moçambique. This report documents the achieved experiences of this project.


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GALBIATI, A. F.; SILVA, G. C. da; MARCOS, V. G. ; AFFONSO, M. V. G.; PAULO, P. L. (2007): Application of Ecological Sanitation and Permaculture Techniques. Food and Water Security for Indigenous Tribes and Rural areas in Brazil . Brazil: Federal University of Mato Grosso do Sul. PDF

This paper describes a demonstration project carried out in an indigenous tribe in Brazil. The project comprised the implementation of arborloo-type toilets and banana tree circles with greywater irrigation.


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MORGAN, P.; SHANGWA, A. (2008): Teaching Ecological Sanitation at Chisungu Primary School. Epworth: Zimbabwe.. Zimbabve: Aquamor. PDF

This presentation gives an example how school children in Zimbabwe get educated on the idea of arborloo/VIP.


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SAYRE, E.; WAND (Editor) (2008): Practical Experiences in implementing Ecological Sanitation during Extreme Dry Regimes . Philippines: Water, Agroforestry, Nutrition and Development Foundation. PDF

This presentation of WAND-Foundation provides information on experiences achieved in the field of implementing various technologies of ecological sanitation in the Philippines. It contains a variety of local technologies (including arborloos), financing mechanisms and emerging opportunities.


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CRS (Editor) (2012): Promoting Ecological Sanitation in Ethiopia through the Arborloo Latrine. Baltimore: Catholic Relief Services (CRS). URL [Accessed: 22.02.2012]. PDF

The ArborLoo is successful in Ethiopia because: its design addresses past obstacles to sanitation; its construction is simplified, reducing financial outlay and construction costs; it emphasizes marketing and participatory efforts; and it increases the output of additional organic fertilisers.


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SHANGWA, A.; MORGAN, P. (2008): How We Made an Arborloo Which Can be Upgraded to VIP. The Chisungu Primary School Water and Sanitation project. Stockholm : Ecological Sanitation Research (EcoSanRes), Stockholm Environment Institute (SEI). URL [Accessed: 19.06.2013]. PDF

The Arborloo is the simplest ecological toilet and is an effective way of starting low cost sanitation programmes. It also demonstrates how valuable the nutrients in human excreta can be. This presentation gives an insight into the following aspects: - What is anArborloo? - What is an Arborloo? - Stages in life of the Arborloo - Planting trees on or near Arborloo pits - Stages in the construction of the Arborloo - Vent pipes - Construction of the Blair VIP


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MORGAN, P. (2010): Ecological Sanitation in Malawi. Stockholm : Ecological Sanitation Research (EcoSanRes), Stockholm Environment Institute (SEI). URL [Accessed: 20.06.2013]. PDF

This illustrative presentation on ecological sanitation in Malawi, focuses on the concept of ecological sanitation, types of eco-toilets and basic methods of recycling nutrient from human excreta.


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MORGAN, P. (2007): Available Sanitation Technologies for Rural and Peri-Urban Africa. Stockholm : Ecological Sanitation Research (EcoSanRes), Stockholm Environment Institute (SEI). URL [Accessed: 20.06.2013]. PDF

The presentation allows for a good overview on existing types of pit latrines in Africa, but also on other types of sanitation technologies such as the conventional flush toilet, the pour flush toilet, and the urine diversion dehydration toilet (UDDT).


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MORGAN, P. (2003): Experiments with Ecological Sanitation and Pit Emptying in Maputaland, South Africa. A Description of Visits Made in 2000 and 2003. Stockholm : Ecological Sanitation Research (EcoSanRes), Stockholm Environment Institute (SEI). URL [Accessed: 20.06.2013]. PDF

This document describes the experimental design of ecological sanitation and pit-emptying trials in Maputaland, South Africa. It describes the situation found at field visits in 2000 and 2003.


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MORGAN, P. (2007): The Arborloo Book for Ethiopia. How to Make a Simple Pit Toilet and Grow Trees and Vegetables. Stockholm : Ecological Sanitation Research (EcoSanRes), Stockholm Environment Institute (SEI). URL [Accessed: 20.06.2013]. PDF

This booklet describes how to make a toilet which is both low cost and easy to make. Builders and artisans are not required, once the householder has learned the basic methods of construction.


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SMET, J.; ACHIRO, B.; MOMMEN, B.; TURYAREEBA, P.; LeaPPS (Editor) (2008): An Ecological Approach to Sanitation in Uganda using Arborloo and Fossa Alterna. LeaPPS Case. Uganda: Learning for Practice and Policy on Household and School Sanitation and Hygiene (LeaPPS). PDF

This paper gives an overview on arborloo and fossa alterna technologies referring to existing projects in Africa.


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MORGAN, P. (2010): Ecological Sanitation in Malawi. Stockholm : Ecological Sanitation Research (EcoSanRes), Stockholm Environment Institute (SEI). URL [Accessed: 20.06.2013]. PDF

This illustrative presentation on ecological sanitation in Malawi, focuses on the concept of ecological sanitation, types of eco-toilets and basic methods of recycling nutrient from human excreta.


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MORGAN, P. (2007): Lessons from a Low Cost Ecological Approach to Sanitation in Malawi. Washington: Water and Sanitation Program (WSP). URL [Accessed: 20.06.2013]. PDF

Low cost Ecological Sanitation programs in Malawi have led to the building of over 11,000 compost-producing toilets since 2003. While the toilets are affordable and simple to construct, the fact that they convert human waste into valuable odour-free compost, enables cost recovery for households and is a prime driver in popularizing EcoSan designs. This field note summarizes the lessons learned thus far in Malawi’s efforts to popularize ecological sanitation.


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MORGAN, P. (2005): Ecological Sanitation in Southern Africa. Many Approaches to a Varied Need. Stockholm : Ecological Sanitation Research (EcoSanRes), Stockholm Environment Institute (SEI). URL [Accessed: 21.06.2013]. PDF

This document describes the ecological sanitation situation in South Africa, focussing on the range of technological options, promotional methods and recycling methods and the problem areas.


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MUELLEGGER, E. (Editor); LANGEGRABER, G. (Editor); LECHNER, M. (Editor) (2010): The ROSA Project. (= Sustainable Sanitation Practice, 4). Vienna: Ecosan Club. URL [Accessed: 01.07.2013]. PDF

The ROSA project stands for Resource-Oriented Sanitation concepts for peri-urban areas in Africa. This Sustainable Sanitation Practice (SSP) issue contains the following contributions: 1. Introduction to the ROSA Project, 2. From Pilot Units to Large-Scale Implementation - Ethiopia, 3. Implementation of UDDTs at Schools - Kenya, 4. Urban Agriculture for Sanitation Promotion, 5. Operation an Maintenance in Practice, 6. Experiences from Strategic Sanitation Planning, 7. Main Findings and Main Achievements.


Reference icon

SUSANA (2009): Low-cost Arborloo with separate collection of urine in EcoPees. SuSanA on Flickr. SuSanA. URL [Accessed: 09.06.2011].


Awareness Raising Material Library

Reference icon

TUHUS-DUBROW (2008): Waste? Not. In: The Boston Globe. URL [Accessed: 21.02.2010]. PDF

Critical article on conventional end-of-pipe wastewater approaches, introducing some alternatives such as biogas digester, arborloos or the fossa alterna.


Reference icon

NWP (Editor) (2006): Smart Sanitation Solutions. Examples of innovative, low-cost technologies for toilets, collection, transportation, treatment and use of sanitation products. (= Smart water solutions). Amsterdam: Netherlands Water Partnership (NWP). URL [Accessed: 13.04.2010]. PDF

Smart Sanitation Solutions presents examples of low-cost household and community-based sanitation solutions that have proven effective and affordable. A wide range of innovative technologies for toilets, collection, transportation, treatment and use of sanitation products that have already helped thousands of poor families to improve their lives is illustrated.


Training Material Library

Reference icon

SIMPSON, M.; Holistic Innovations in Agriculture Programming (Editor) (2009): Arborloos Improved Hygiene Intervention increases Agricultural Production. (pdf presentation). Washington, D.C.: Catholic Relief Service (CRS): East Africa Regional Office. PDF

This presentation by CRS contains a well-structured overview of the arborloo. The slides contain historical information as well as information on technological, economic and agricultural aspects.


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WATER AID (Editor) (n.y.): Construction Means and Methods for the Arborloo Sanitation Practices. Nigeria: WATER AID . PDF

This note from Water Aid provides information on how to construct arborloo latrines, its use, means of alternating between pits and making compost manure out of it.


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WATER AID (Editor) (n.y.): New Sanitation Technologies for Communities with Poor Soil . (pdf presentation). Nigeria: WATER AID. PDF

This briefing note presents concepts and technologies that have been developed to facilitate development of effective sanitation programme in communities with challenging hydro-geologic conditions also mentioning arborloo.


Important Weblinks

http://www.oursoil.org/ [Accessed: 28.01.2010]

This link to www.oursoil.org provides information on arborloo based on the work of Peter Morgan in Malawi.

http://www.commons.wikimedia.org/wiki/File:Arborloo-en.svg [Accessed: 20.11.2009]

Easy to understand poster on the functionality of an arborloo toilet (English).