Cover Image
close this bookSanitation Promotion (SIDA - SDC - WSSCC - WHO, 1998, 292 p.)
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View the documentAcknowledgements
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close this folderThe challenge - A sanitation revolution
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View the documentThe problem of sanitation - WSSCC Working Group on Promotion of Sanitation
View the documentCommonly held wrong assumptions about sanitation - WSSCC Working Group on Promotion of Sanitation
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close this folderGaining political will and partnership
close this folderPrinciples and guidelines
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View the documentAdvocacy for sanitation - Sara Wood1 and Mayling Simpson-Hébert2
View the documentMobilizing the media for sanitation promotion - WHO, Geneva, Switzerland
View the documentMobilizing partners for sanitation promotion - Sara Wood1 and Mayling Simpson-Hébert2
View the documentPrivate-sector involvement in promoting sanitation - Sara Wood1
View the documentSocial marketing for sanitation programmes - Sunil Mehra1
close this folderCase studies
View the documentSecuring political will in Uganda - John Odolon1
View the documentSanitation in Surat - Ashoke Chatterjee1
close this folderPromotion through better programmes
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View the documentImportant elements for a successful national sanitation programme - WSSCC Working Group on Promotion of Sanitation
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View the documentPrinciple cards - WSSCC Working Group on Promotion of Sanitation
View the documentFeatures of better sanitation programmes - WSSCC Working Group on Promotion of Sanitation
View the documentPrinciples of sanitation in emergency situations (1) - John Adams1
View the documentGuidelines on achieving water supply and sanitation in peri-urban areas - WSSCC Urbanization Working Group
View the documentPrinciples of the strategic sanitation approach - Albert M. Wright1
close this folderEmpowerment
View the documentA gender perspective in sanitation projects - Angela Hayden1
View the documentHygiene behaviour-change: lessons from other sectors - Carol Jenkins1
View the documentParticipatory approaches to community empowerment - John Odolon1
View the documentParticipatory monitoring and evaluation of sanitation projects - Jennifer Rietbergen-McCracken1, Sara Wood2 and Mayling Simpson-Hébert3
View the documentFinancing low-income household sanitation facilities through household credit - Robert Varley1
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View the documentChecklist for planning better sanitation projects - WSSCC Working Group on Promotion of Sanitation
View the documentChecklist for planning sanitation in emergency situations - Mayling Simpson-Hebert1
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View the documentGender checklist for planning sanitation projects - Angela Hayden1
close this folderPromotion through innovation
close this folderChild-centred approaches
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View the documentPromoting sanitation through children - Angela Hayden1
View the documentThe Bal Sevak programme in India - Nandita Kapadia-Kundu and Ashok Dyalchand1
View the documentThe HESAWA school health and sanitation package - Eben S. Mwasha1
View the documentChildren as health and hygiene promoters in South Africa - Edward D. Breslin1, Carlos Madrid2 and Anderson Mkhize3
close this folderParticipatory approaches
View the documentPromoting sanitation through community participation in Bolivia - Betty Soto T.1
View the documentStrengthening a rural sanitation programme using participatory methods in Uganda - John Odolon1
close this folderInnovative technologies
View the documentTowards an ecological approach to sanitation - Uno Winblad1
View the documentPromoting composting toilets for Pacific Islands - Leonie Crennan1
View the documentPeri-urban sanitation promotion in Mozambique - Darren Saywell1
View the documentUrine as fertilizer in Mexico City - Yoloquetzatl Ceballos1
View the documentExperimenting with dry toilets in El Salvador - Ron Sawyer1 and George Anna Clark2
View the documentMeeting demand for dry sanitation in Mexico - Ron Sawyer1
View the documentLow-cost sewerage - Duncan Mara1
View the documentWorm composting and vermitechnologies applicable to sanitation - S. Zorba Frankel1
View the documentBibliography
View the documentBack cover

Meeting demand for dry sanitation in Mexico - Ron Sawyer1

1 SARAR TransformaciC, Mexico.

A viable sanitation solution to water-scarcity and pollution

Water scarcity and water pollution caused by inadequate and inappropriate sanitation services that use water to transport human excreta motivated Cr Ae and the voluntary organization ESAC (Espacio de Salud - “Health Space”) to develop a complementary strategy to increase access to and use of dry toilets in Mexico. The core elements of their approach are the production and sale of urine-diversion toilet seat risers, health and environmental education, organizational support, and technical training and follow-up. Clients include low-income community groups, governmental agencies, independent architects, and other NGOs. As the demand for these toilets increases in Mexico, Cr and ESAC are refining their range of products, while also grappling with the broader issues related to municipal and environmental planning and management.

The sanitation problem

Espacio de Salud works in southern and south central states of Mexico. In much of this area urban settlements are built upon very porous volcanic rock and beneath the volcanic rock are large aquifers. Wells tapped into these aquifers are the sources of drinking water for these populations.

Sewerage is not an option, firstly because hard volcanic rock would need to be blasted away to lay pipes, and secondly because communities with sewer systems have found that maintenance of these systems and treatment of the wastewater are too costly for their populations. Communities are not willing to incur these high costs and these systems generally fail as a result. Pit latrines are also out of the question. They cannot be dug and even if they could be, they would also pollute the aquifer. As a result, residents build flush toilets over the rock and sink PVC pipes directly into the aquifer below, or in areas that have a thin layer of topsoil, they dig shallow pit latrines that ultimately leach into the groundwater. These toilets have caused extensive pollution of the groundwater and undissolved faeces can actually be seen, through holes in the porous volcanic rock, floating in the aquifer, and in the springs which flow from it.

These areas, not surprisingly, experience frequent epidemics of diarrhoeal diseases, cholera and typhoid. More and more people are making the link between this inadequate method of sanitation and the epidemics. This connection has increased demand for sanitation options that do not pollute the groundwater. Espacio de Salud has tried to meet this need by promoting the use of dry aboveground toilets and removal of the sanitized faeces, usually one to two years later, to land safely away from the aquifer. Their education and promotion activities have raised awareness about dry sanitation options. More and more families and communities have become convinced of the advantages of this sanitation system for their health and want dry sanitation for all. They realize that pollution from one family can contaminate everyone's drinking water.

Espacio de Salud works in these areas of difficult terrain and groundwater pollution, offering assistance to households and communities wishing to convert their existing sanitation systems to dry systems.

Programme description

Production - Cr Ae

Cr Ae is an independent entrepreneur who has spent the past fifteen years producing and advocating the use in Mexico of modified Vietnamese double-vault toilets. ESAC is a small NGO concerned with promoting improved health and environmental conditions among low-income groups. Over time, Cr and ESAC have evolved a collaborative, symbiotic relationship that has contributed to significant improvements in the sector.

Urine-diversion toilet seat

Cr's operation is deliberately unsophisticated. As a family-run business, his workshop produces approximately 30 urine-diversion toilet seat risers per week. More than 6000 toilet seats have been sold. The profit from the sale of the polished cement seats (approximately US$ 17 or 126 Mexican pesos per unit) is used to finance his overall operation, including low-key promotion, training in toilet construction and use, and advocacy for change in environmental sanitation policies and legislation. Cr receives visitors to his home almost daily to order toilets or simply to request information. He is assisted in his outreach by three persons, including his brother.

Cr provides short-term technical training and support, which is included in the cost of the hardware, to individual clients, bricklayers, governmental agencies, and NGOs. An additional quota is often charged for institutional training workshops and special presentations. The pricing structure of the toilet seats permits Cr to partially subsidize the costs of the toilet seats for extremely poor clients who do not have access to adequate financing.

Education and empowerment - Espacio de Salud A. C.

ESAC works primarily with women and provides health and environmental training to organized groups, community leaders, extension workers, and teachers in the states of Morelos, Guerrero, and Oaxaca. Although ESAC does not promote a specific technology, cholera outbreaks in Guerrero and rapid environmental degradation in Morelos have generated frequent requests for improved sanitation, in general, and dry toilets, in particular.

ESAC responds to communities' demands by using participatory methods to assist them in analysing the causes of their problems and to identify possible solutions. When and if the community members decide to build dry toilets, ESAC trains them in construction, use, and maintenance, and provides follow-up monitoring and support.

Because of its limited resources on the one hand, and a focus on empowerment and fortifying democratic processes on the other, ESAC only responds to requests from organized popular groups. The NGO's experience and expertise in training community workers and in strengthening organized groups has spread by word of mouth, especially among grass-roots religious communities whose motivation for changing current conditions - including environmental conditions - is based on Biblical reflection. These groups expect to participate actively in decision-making.

All individual and group requests for hardware support are referred to Cr, who sells either the toilet seats or the fibreglass moulds and provides training in the production process. Although the groups are also offered advice on how to use modified buckets to make their own urine-diverting toilet seats, almost all prefer to purchase their seats ready-made.

As the demand for dry toilets has increased, Cr and ESAC have decided to make the training of community workers their highest priority. As a result of this focus, they have jointly developed and produced educational and training materials - including an attractive, full-colour poster showing a range of dry toilet models, as well as the basic technical design drawing.

Figure 1. The modified Vietnamese double-vault toilet

Technology - modified Vietnamese double-vault toilet

The modified Vietnamese double-vault toilet is designed to permit reuse of human excrement for agricultural purposes after it has been “treated” by keeping it in a sealed chamber for a minimum of six months. During that time the faeces become very dry, making it impossible for pathogens to survive. The two sides of the double vault toilet are alternated every six months at minimum. As excreta are not traditionally used as fertilizer in Mexico, there is no incentive to open a vault before the minimum six months of drying time is complete. The usual waiting period is 8 to 18 months before removal. It is estimated that a family of five to six members can produce a little less than half a cubic metre “harvest” per year.

Because of the impossibility of laboratory analysis for every toilet in use, it is recommended that the product not be used in vegetable gardens. However, it can be used in fruit orchards and to grow grains. Composting to improve the product's texture and fertility, and to modify its pH, can be undertaken.

Fermented urine is recommended as a fertilizer. Before sealing the container to avoid loss of nitrogen, users often add a handful of soil as a catalyst for the fermentation process. For fertilization purposes, users have reported varied dilution ratios of urine to water (from 1:5 to 1:20).

Unfermented urine can be sprayed as a fungicide. Indigenous people in southeastern Mexico claim that the use of urine as a fungicide was a traditional Mayan practice.


Raising awareness. One of the most important accomplishments of the programme has been the greater awareness that has been generated regarding sanitation-related environmental and health issues. Dry toilets are less often requested primarily on the basis of convenience, and more often on the basis of health concerns.

An increase in requests for dry systems from local architects reflects a greater environmental awareness (and demand) on the part of their middle-class clients.

Product development. In response to the increasing demand from diverse sectors of the population, Cr has been able to develop a broader range of products, including improved designs of toilet seats, using a variety of different materials. The brightly painted polished concrete remains the standard material used for the urine-diverting seat, as well as a companion urinal for men who are so inclined. Cr has produced a prototype portable fibreglass seat for public fairs, large private parties, and other special events; and together with another nongovernmental group, he is experimenting with recycled-plastic seats. An up-market ceramic seat is also under consideration.

Replication. Although the marketing is very low-key, the demand for urine-diversion seats is gradually increasing. To satisfy requests for dry toilets further afield, Cr sells the moulds (for 2500 Mexican Pesos, or approximately US$ 320) and assists local groups in establishing small workshops to produce the seats and to generate local employment. Beginning with the establishment of three independent workshops in Oaxaca in 1990, there are now about 15 independent, small-scale manufacturers of urine-diversion units, in different parts of the country.

Policy and regulatory environment. Cr is a political cartoonist, often commenting on environmental problems. His aesthetically appealing drawings, used in educational materials, invite the reader to reflect upon broader social and political values. As part of an awareness-building campaign and to increase social pressure for modification of the state environmental legislation, he also writes articles for local newspapers. An important, recent “victory” is that the state Architects Association will be submitting a proposal to the municipality of Cuernavaca, a city of over half a million people, whereby dry toilets become acceptable under the standards permitted for issuing housing permits.

Difficulties encountered

The most significant difficulty has been overcoming the negative reputation of project “failures”. When an external agent imposes its own resources and rhythms on the community, the project often fails. In these cases, the community has not identified alternative sanitation as a necessity. It has no knowledge, much less interest, in the dry toilet or in how it should be built and maintained. Fieldworkers are often uninformed about the technology, as well as community empowerment approaches.

A classic example is during election times, when a government entity decrees that a given number of toilets will be built, whether the community wants them or not. Likewise, in an economically stressed country, with a history of paternalistic relationships, many communities have become accustomed to passively receiving a variety of project offers from governmental and nongovernmental agencies. Often the community agrees to whatever is proposed, whether the need is felt or not, expecting that some advantage will be gained.

The families in these cases typically use the constructed toilet as storage space or a pigpen. When the dry toilets do not “work”, word gets around very fast. Overcoming the negative reputation of a technology is extremely difficult.

As the “flush and forget” mentality invades Mexico, choosing dry sanitation over conventional sanitation is rare. Having “modern” conveniences is a status symbol, while being environmentally “correct” carries no prestige.

Owing to the large and increasing demand, coupled with institutional financial constraints, consistent follow-up has not always been possible. At times, it has been necessary to make the difficult choice between either responding to another, new community or continuing with the old. Under these circumstances it has been equally difficult to give adequate attention to systematic monitoring and evaluation. For example, there is no clear data on how many of the 6000 urine-diversion seats produced are actually in use.

Lessons learned

The programme has discovered that:

· Large-scale promotion of dry sanitation should be avoided. Experience has shown that the lack of adequate education and institutional follow-up can lead to failure and abandonment of the approach.

· The various advantages of the dry toilets can be better appreciated and assimilated by users when they are explained and supported by established, organized groups.

· Dry systems are significantly less expensive than conventional waterborne systems. Although the costs of the specific components vary considerably, depending upon the materials used, a complete unit, including the superstructure and a cement roof, is approximately 1200 Mexican Pesos (US$ 150+);

· There are important environmental advantages to using dry toilets. Rather than producing 100 000 to 150 000 litres of contaminated sewage water per family per year (enough to fill a 2 x 2.5 x 30 m cistern), the dry system produces approximately 5000 litres of liquid fertilizer (urine) and 300 to 500 litres of “composted” soil conditioner.

· Seeing is believing! A visit to a home with a dry toilet, preferably one which is integrated within the house, rather than operated as a separate structure, is especially helpful for convincing potential users.

· Extension workers, who are generally considered of high status, are taken quite seriously when they have dry toilets in their own homes. This is a particularly important consideration when working in a region where past dry sanitation projects are considered to have “failed”.

· It is advisable not to talk about financing mechanisms (whether revolving loans, outright gifts or demonstration models) during the first discussion. Otherwise, there is a strong likelihood that this subject will become the focus, and distort the needs assessment.

· Encouraging families to be responsible for their own wastes is certainly acceptable; forcing them to accept any one technical solution is not. Extension workers should know when to bow out gracefully, leaving communication lines open, when communities decide (whether explicitly or implicitly) not to accept an innovative sanitation approach.

· Rather than succumb to the temptation of building the first toilet for public use, it is best to wait patiently until a few families decide to take the risk to experiment. Public toilets are notoriously dirty. Dry toilets are no exception.

· Several demonstration models are better than just one, to prevent the “brave” family from being pressured from all sides - either to succeed or fail. A “brave souls” support group can be helpful, with frequent trouble-shooting check-ups of the toilets by community workers.

· To counteract the destructive impact of “modern values” and conventional wisdom, groups should be actively involved in a participatory critical analysis of their situation. If provided with the tools to make informed choices, participants will generally assume responsibility for making decisions regarding their impact on the environment. Whether they decide to construct a dry toilet or not, this learning process should benefit them.

· Alternative systems should be attractive. Supplying “modern-looking” urine-diverting toilet seats in a wide range of colours has helped tremendously, as have educational posters, which show dry toilets installed within a variety of settings, including “luxurious” bathrooms.

Future plans

Proposals for future work include:

· Developing a guide for the handling and use of the processed faecal material (including guidelines for laboratory analysis).

· Developing a guide on the handling and use of the urine.

· Updating the existing construction manual, including a range of toilet styles and construction materials.

· Updating the existing users operation and maintenance guide.

· Developing small posters on proper use, appropriate for hanging in the bathroom.

ESAC is particularly interested in modifying the dry toilet system to incorporate red worm “vermi-culture”. It is anticipated that this innovation might require only one chamber, thus reducing construction costs, and result in a far superior compost product. ESAC is presently experimenting with vermi-composting of the harvested dry toilet compost, mixed with horse manure.

Additional laboratory analysis and research is necessary to determine acceptable levels of pathogen counts during different stages of the process and under different conditions. Thus far, the programme has relied exclusively on tests done by others.

The programme is beginning to make links with parallel urban composting centres to establish practical mechanisms for reuse of dry latrine output as the programme continues to expand.

Key institutions and responsible persons

Cr Ae
Helechos #5
Colonia Jacarandas
Cuernavaca, Morelos
62420 Mexico
Phone and fax: +52 73 15 49 11

George Anna Clark
Espacio de Salud, A. C. (ESAC)
Apartado Postal 1-1576
Cuernavaca, Morelos
62001 Mexico
Phone and fax: +52 73 18 07 20