Why is it important?
Only two in five people in the world have access to safely managed sanitation services. 4 billion people suffer from water shortages for one month or more per year, a significant and alarming indicator that there is not enough water to meet human demand. (1)
In many countries, the lack of management and treatment of faeces is a major health issue. Today, nearly two billion people use a drinking water source contaminated with faeces, putting them at risk of contracting cholera, dysentery, typhoid and polio. The World Health Organisation estimates that contaminated drinking water causes more than 500,000 deaths from diarrhoea each year. (2)
Dry toilets do not need water to function. Drinking water resources are therefore neither used nor polluted. Dry toilets are a low-cost, easy-to-use and quick-to-implement solution that effectively combats water scarcity and pollution. They are essential to overcome the lack of water and sanitation infrastructure in areas where water is scarce. They improve user hygiene and better manage biological waste. (3)
Toilet waste can be composted and used as organic fertiliser instead of chemicals, whose use contributes to soil depletion worldwide. Dry toilets are therefore also a sustainable way to combat chemical pollution and soil nutrient depletion worldwide.
About 1.7 billion people live without basic sanitation and about 500 million of them practice open defecation (5)
A dry toilet can save 6 to 9 litres of flush, or 45 litres per day and about 15,000 litres of drinking water per person per year (6)
What is the solution?
Dry toilets do not use water. The excreta fall into a receptacle. Dry, carbon-rich organic material such as sawdust, shavings, fine straw or hay should then be added. This is then composted. Excrements will eventually disappear naturally.
The receptacle can be a simple bucket of about 20 litres, usually placed in a wooden box. It is then necessary to empty the bucket every 2 or 3 days. There are also dry toilets with a large receptacle that can be used for several weeks to several months, or even a year.
There are two types of dry toilets. Non-separating toilets collect both faeces and urine in the same receptacle. In separating toilets, faeces fall into a receptacle and the urine is discharged separately. There are many models of dry toilets, with different variations, to suit all circumstances, locations, and budgets. These range from simple self-built wooden boxes costing a few dozen euros to more sophisticated models, bought ready to use, costing thousands of euros.
Mastering the composting technique is one of the key success factors (or obstacles) for dry toilet projects. The composting phase takes place either directly in the dry toilet receptacle or outside (usually in a garden). Composting is accompanied by heat production, especially during the fermentation stage. It is very important to protect the compost from access (dogs, cats, children) because of the risk of spreading pathogenic organisms. The composting process takes time (2 years).
Composting is a natural process of decomposition of organic matter which is transformed into very fertile soil (compost, humus). The soil resulting from composting is a resource for plants. A continuous composting dry toilet seeks to recreate the necessary conditions for an efficient composting process. Human excrements are rich in nitrogen (urine) and organic matter (faeces). The addition of dry material (which contains a lot of carbon) allows the moisture to be absorbed and the carbon/nitrogen ratio to be balanced, thus promoting the decomposition of the material through composting. Micro-organisms transform this waste into fertilisers. (8)
#1 Assess the situation, the needs & the system
Evaluate the available space and the distance to a water resource (potential pollution). The answers to these questions can help analyse the situation. What type of dry toilet to install depending on the number of people? How big should the receptacle be (needs, capacities)? Is the compost usable on site, or does it need to be disposed of? What type of dry material to use, sawdust, soil, dried leaves? What is the main priority of installing such a toilet? What are the risks, costs, advantages, and points of attention?
#2 Install dry toilet systems & locate compost sites
Install the model of toilet that best suits the users from an economic and cultural point of view and the local conditions of the countries concerned. Clearly display the operating instructions to users. Choose wisely compost sites, at a safe distance from any public facility or water resource. Protect them from unwanted visitors.
#3 Train staff
Train the people who will be responsible for operating and maintaining the system, both the toilets and the compost sites. Create a skilled workforce.
#4 Cleaning & maintenance
Dry toilets must be well maintained and washed with care and by well-trained professionals, as there is a high possibility of disease transmission. Similarly, compost must be well managed. Respect hygiene rules for handling at all times.
#5 Raise users’ awareness
Inform and be transparent with the users about the importance and functioning of such a toilet and how it can combat or respond to certain problems encountered, of a hygienic nature (diseases), utility (organic fertilizer without chemicals), economy (reduced price for sanitation) and environment (pollution and water shortage).
#6 Collaborate with local farmers
Look for local farmers who could use the compost produced from toilet waste. Inform them of its potential as a (free) organic fertiliser instead of chemicals.
- Water savings and significant reduction in drinking water consumption
- Improved climate change resilience in water-scarce areas
- Reduced water and soil pollution from faeces
- Disease reduction
- Users’ hygiene and safety improvement
- Reduced water and soil pollution from chemical fertilisers thanks to compost use
- Natural soil fertilisation thanks to compost
- Money savings
Prerequisites and specifications
- Can be installed anywhere without the need for major renovations
- Require stocks of sawdust, shavings, ash, straw, soil
- Requires more time and human resources than traditional water-based toilets (maintenance of the toilets and especially compost management)
- Social acceptance (cultural and psychological resistance), and therefore information and awareness raising of the decision makers and users is required
- Clearly display the operating instructions to users
- Good dimensioning of receptacles and compost sites, depending on the needs and capacities
- Good management and maintenance of the toilets, including regular emptying of receptacles, respecting hygiene rules for handling
- Good storage and transport of excreta, which is more difficult in urban contexts
- Be technically appropriate and economically viable
- Can sometimes release odours. Dry material and proper ventilation limits and removes odours to the outside
- Can reach watercourses if not well managed or in case of heavy rainfall. Location of toilets and compost sites should be chosen wisely
- Local spread of pathogens if compost is not well located and managed. Compost sites should be located at a safe distance from public facilities, especially hospitals and schools
- Risk of pathogen transmission to market gardening (vegetables eaten raw) if composting time is not long enough (lower risk than from a river)
Construction of toilets and water kiosks in Malawi
The international charity, Habitat for Humanity, Great Britain in collaboration with local partners built 135 Ecosan composting dry toilets and helped train over 6000 people on hygiene and sanitation. More than 135 families have benefited from the new toilets. (9)
Basic sanitation and organic waste compost for agriculture in Benin
The project has built 30 latrines, 28 at household level and two for public use in Benin. Additionally, a compost site has been built to reprocess sorted organic waste together with hygienised excreta. The collection of excreta and urine containers is handled by a group of local gardeners who is also responsible for the composting process and for the marketing of the compost. In this way both categories of waste, organic and excreta, are revalued for agricultural purposes creating a profitable compost-market and offering to the farmer an ecological alternative to industrial fertilisers. Through this project the common practice of open-air defecation is also reduced achieving a preservation of public health. In parallel, communication and awareness-raising about the EcoSan approach is increasing its acceptance among a larger public. (10)
A modern Chinese city using dry toilets
Through a cooperation between several international stakeholders and a collaboration with the EcoSanRes program and SIDA, a city of 7000 inhabitants has been built entirely using sustainable water and sanitation techniques. The Sino-Swedish Erdos Eco-City Project was completed in 2007. The dwellings are equipped with urine diversion dry toilets for later use in local agriculture. Faeces are collected and composted and used in soil amendment. (11)
Awareness raising on dry toilets in India
Friend In Need India is an organization that functions as a two-pronged teaching, training, and action research laboratory. Under the project “Improving WASH Infrastructure”, FIN promotes the use of dry toilets according to the Indian culture. Although this system is not new to the region (FIN has built more than 300 toilets), awareness raising remains a challenge in the country. As a result, FIN is working on design innovations and the construction of high-quality, climate-resistant toilet and bathroom complexes. (12)
Ecological sanitation acceptance and agricultural valorisation in Haiti
The symposium “Sanitation in Haiti: prospects for development” was organised in 2011 by local and international NGOs to raise awareness and train local stakeholders on dry toilets opportunities. The social approach of the sanitation issue in Haiti was presented, along with solutions, obstacles, experiences and actions in progress. (13)
Tools and good practices
Dry toilets presentation
Illustrated slide show presenting dry toilets, their operating principle, their construction, their advantages, their disadvantages, and their success factors. (in French)Read here
Toilets That Make Compost Low-cost, sanitary toilets that produce valuable compost for crops in an African context, EcoSanRes Programme SEI
A guidebook with practical information for the construction, maintenance, and benefits of dry toilets in rural, peri-urban, and urban areas of Africa. Several types of dry toilets are presented according to local conditions, costs, and final needs and how compost can be obtained from the excreta for use in crop fields.Read here
Compendium of sanitation technologies in emergencies
The compendium is a comprehensive and user-friendly online capacity development tool for sanitation solutions in emergency settings. It provides detailed information on key decision criteria for tried and tested emergency sanitation technologies, information on cross-cutting issues and available case studies.Read here
Compilation of 27 case studies on sustainable sanitation projects from Sub-Saharan Africa, Sustainable Sanitation Alliance
Case studies of sustainable sanitation projects from around the world to demonstrate the wide range of available technologies for sustainable sanitation systems.Read here
Good practice guide: Dry toilets at home, Toilettes Du Monde
This guide presents recommendations for the installation and use of dry toilets at home with explanations on the main principles of eco-sanitation, a presentation of the different types of dry toilets, details on the management of "by-products", technical information for installing dry toilets at home. (in French)Read here
Good practice guide: Composting dry toilet by-products, Toilettes Du Monde
This is a guide summarizing the main principles and good practices to be respected for the use of dry toilets on a family scale. It aims to provide clear information to individuals using or wishing to use dry toilets. (in French)Read here
An engineer's guide to latrine slabs, Water, Engineering and Development Centre
This brochure highlights the design, construction, and maintenance features of dry toilets, which contribute to improved safety and comfort for users.Read here
Recommendations for the safe use of urine and faeces in ecological sanitation systems, EcoSanRes Programme SEI
This guideline brings together recommendations for the safe use of faeces and urine in ecological sanitation systems, with practical recommendations for use in agriculture after composting. (in French)Read here
To go further
The EcoSanRes (Ecological Sanitation Research) Programme aims to develop and promote sustainable sanitation in the developing world through capacity development and knowledge management as a contribution to equity, health, poverty alleviation, and improved environmental quality.Read here
Terr’Eau is a French organisation that provides on their website informative documentations on dry toilets, composting and separating toilets, ecological grey water treatment systems. (in French)Read here
The Solidarité-Eau (pS-Eau) program is a French multi-actor network committed to guaranteeing access to water and sanitation for all and to the sustainable management of water resources in developing countries. (in French)Read here
(1) UNESCO World Water Assessment Programme, Leaving no one behind: The United Nations world water development report, 2019. Read here.
(2) WHO, Fact sheet on drinking water, 2022. Read here.
(3) IISD, Dry Toilets: An Approach to Provide Safe Sanitation and Sustainable Sewage Treatment?, 2019. Read here.
(4) WHO, Fact sheet on drinking water, 2022. Read here.
(5) Global Dry Toilet Association of Finland. Consult their website here.
(6) Ecosave, What are dry toilets? Read here.
(7) Le Blog de l’Habitat Durable, Dry toilets: advantages, disadvantages, cost and regulations. In French. Read here.
(8) pS-Eau, Dry toilets presentation, 2013. In French. Read here.
(9) Habitat for Humanity UK, Building Toilets & Clean Water Kiosks in Malawi. Read here.
(10) Sustainable Sanitation Alliance, Combined solid waste management and basic sanitation Lokossa, Mono region, Benin – Case study of sustainable sanitation projects, 2014. Read here.
(11) Terr’eau, Projet novateur en Chine. In French. Read here.
(12) Friend in Need India, Wash Innovations. Read here.
(13) Ecological sanitation in Haiti: Acceptance and agricultural valorization, 2011. In French. Read here.
Cover photo © Amy Reed/Unsplash.