SOIL: Ecological Sanitation

Ecological sanitation is a multidisciplinary community-based approach which can:

Despite dedicating a decade (1981-1990) to water and sanitation issues by the United Nations General Assembly, waterborne illness is still the third leading cause of mortality in the developing world. The burden of waterborne illness falls disproportionately on children, contributing significantly to high mortality rates in those under age five, malnutrition, and growth stunting.

Nearly half of the world's population has no access to a sanitation system and most sewer water in impoverished countries (100% in Africa, 86% in Latin America and the Caribbean, and 65% in Asia) is discharged without treatment posing a serious public health risk and contaminating aquatic ecosystems.

Meanwhile, as nutrients from human wastes accumulate in estuaries and other aquatic ecosystems, much of the world's farmland is being progressively degraded, and in many regions of the world productive capacity has stagnated or even declined. This phenomenon disproportionately affects poor farmers, who seldom have access to fertility-enhancing agricultural inputs and are, therefore, dependant on ecosystem services to maintain soil fertility. Without substantial inputs of organic matter to balance harvests, soil biological activity and nutrient availability are reduced and yields decline. Low soil fertility forces many small farmers to find other land, or leave their land and families in search of other work, fracturing the social fabric of rural communities.

The environmental, social and public health crises faced by poor rural communities, point to the urgent need to combat rural poverty and to promote research geared towards regenerating the deteriorated resource base of rural communities. Improved quality of life in rural communities has a much wider scope, as it can reduce the flood of people and resources into already overburdened urban centers.

The concepts behind ecological sanitation are based on natural processes and, as such, have been understood and practiced by indigenous cultures for centuries.China, human wastes, called “night soil”, have been collected and used to enhance agricultural productivity for over 500 years. Throughout Africa and Latin America, peasants will explain that their most productive fruit trees can be found on or near old latrine sites. Even an observant suburban American has noticed that the grass is greener near the septic tank.

Organized efforts to study and promote ecological sanitation as a development strategy are relatively new. The first International Conference on Ecological Sanitation (EcoSan) was held in Nanning China in 2001 and included scientists and promoters from Europe, Africa, Asia and Latin America.Sweden and Germany, however in some countries, such as Malawi, adoption of simple ecological sanitation technologies is spreading with minimal international involvement.

Ecological sanitation projects are popping up all over the world. These projects can span anywhere from small composting toilets in National Parks in the United States to large scale rural development projects in South Africa and Malawi.

Click on the map image to view an interactive map on the EcoSanRes website that has information on ecological sanitation projects across the globe.

Ecological toilets rely on natural processes of decomposition to transform human wastes from a dangerous pollutant into a valuable fertilizer. There are many different approaches and toilet types however all ecological toilets aim to:

How does ecological sanitation differ from conventional sewage treatment?

The two primary sanitation approaches promoted globally are deep-pit latrines and waterborne sewage. Both of these approaches remove raw human wastes from the immediate household environment, and as such the spread of modern sanitation systems and pit latrines has significantly reduced the spread of waterborne disease.However, both approaches have unintended environmental consequences, which effect public health and the long-term sustainability of these sanitation systems.

Deep pit latrines:

Deep pit latrines can be anywhere from 6-25 feet deep and are often lined to prevent collapse. The pit latrine is one of the simplest and cheapest means of disposing of human wastes. If well designed and built, correctly sited and well maintained, it contributes significantly to the prevention of diseases transmitted through human wastes. If pits are dug far from drinking water sources and at least 1.5 m above the water table then the fecal material will be slowly decomposed over a period of years and converted to soil.

Problems with pit latrines arise when:

Groundwater is high: when the groundwater rises above the bottom of the pit, nutrients and microorganisms from human wastes mix with the water supply and can cause serious environmental and public health problems.
Mosquitoes breed in the sludge: because volumes of urine are so much higher than feces, pit latrines generally have standing water where mosquitoes can breed.This can be a source of malaria.

Ventilation is poor: pit latrines can have terrible odors when they are not well ventilated.
Soil is vulnerable to collapse: deep latrines are prone to collapse in some soils, particularly if they are not lined. These pit collapses are often fatal depending on the depth of the latrine and the construction material.
Latrine fills up: when pit latrines are full the only options are to abandon the latrine or pay someone to empty it. In many countries these latrines must be emptied by hand, which is a difficult and dangerous task. Once the latrines are emptied they are often emptied into water sources, like the ocean or river to dispose of the wastes.

Waterborne sewage:

The standard approach to sanitation in industrialized countries is to use water to carry sewage away from the source.Water flush toilets can range from manual pour-flushing into an underground holding tank, to automatic flushing into a municipal sewage system. The public health and environmental consequences of water flush toilets is highly dependant on how the sewage is treated after it leaves the toilet. The vast majority of sewage produced in Africa, Asia and Latin America is discharged into aquatic systems without treatment, and is a major source of water pollution. All water flush toilets share the feature that they require significant amounts of water (up to 6 gallons per flush).

Problems with water borne sewage arise when:

Sewage is discharged untreated: when raw sewage is discharged into aquatic ecosystems it increases both nutrient concentrations and fecal pathogen loads. If these aquatic systems are near or upstream from human habitations sewage can pose a serious public health risk. Even when sewage is discharged far from humans, the nutrients can cause shifts in aquatic ecosystems, which ripple throughout the food chain.

Water is scarce: when water is scarce or people live far from a source water, sewerage systems require constant labor (usually performed by women and children) and often get backed up. Access to running water is largely determined by economic status, and flush toilets are not designed to cater to the poor. As clean water resources become more and more scarce it will become increasingly difficult to maintain flush toilets, even in wealthy countries.

Ecological sanitation:

Ecological sanitation is a concept that grew out of traditional knowledge and recommendations and observations from people using traditional pit latrines. Many people with pit latrines have noticed that addition of ash or soil speeds the decomposition processes, reduces smells and cuts down on flies and mosquitoes. Ecological sanitation seeks to harness ecological processes to ameliorate some of the problems associated with traditional sanitation approaches by:

Using shallow pits: Arborloos and Fossa Alternas are a variation of a pit latrine but they are always shallow, not more than 1 m deep so they are less likely to reach the groundwater table. These shallow pit toilets can also cause groundwater contamination in areas with a very high water table or during floods. Dry toilets are completely above ground and there is no contamination of the toilet site, though there is a potential for leaching into groundwater when the urine is applied off site. Shallow pits also reduce the potential for dangerous collapses.
Reducing standing water: the addition of ash and/or soil to composting pit latrines and dry toilets reduces moisture so composting latrines do not generally contain standing water where mosquitoes can breed. Reducing standing water also cuts down on smells and flies.
Reusing contents as fertilizer: the reuse of composted human wastes constitutes a valuable way to treat the wastes and means that the structures for Fossa alternas and dry toilets can be used for long periods of time as the contents are removed for fertilizer.
Keeping nutrients and pathogens in the soil and out of the water: well-maintained ecological sanitation systems do not seek to dispose of waste but rather to transform it into valuable soil, where nutrients are conserved and pathogens are killed during the composting process.
Not requiring water: composting toilets do not require water to flush or maintain, reducing the environmental costs by conserving a valuable resource.

Ecological sanitation not only benefits the public, by reducing the spread of disease and improving environmental quality, it can also benefit the individual or family using or promoting the toilets by providing livelihood opportunities. The compost and urine that is collected from ecological toilets are valuable fertilizers that can either be sold or used to enhance agricultural productivity on the home garden or family farm. A man in Malawi explained how he had used the profits from his Arborloo fruit trees to buy a goat for his family. Family income can also be increased by improved health resulting from sanitation, healthy family members are more able to work and less money must be spent on hospital bills.

There are also numerous small business opportunities associated with ecological sanitation.Toilet seats for the various types of toilets can be manufactured and sold by entrepreneurial promoters, as can fruit trees, encouraging the development of nursery businesses. Also, as many people will not want to maintain their own toilets, individuals, businesses, and government can provide cleaning services, whereby they remove the compost and resell it to farmers. In many countries where deep pit latrines are prevalent there are people who are paid to empty the latrines. This is a dirty and dangerous job that requires coming in contact with untreated human wastes. With ecological sanitation these same people could be employed but their jobs would have the added dignity of harvesting a valuable resource and the reduced risk of handling only composted waste.

One of the most severe examples in the Western Hemisphere of both soil fertility and sanitation problems is located just 700 miles off the coast of Florida. Haiti, once known as the “Pearl of the Antilles” for its incredible productive capacity, is now a largely deforested landscape where the vast majority of the country's 8 million inhabitants live in abject poverty. Environmental degradation is both the cause and the consequence of poverty in Haiti.

Many of Haiti's resources have been mined over the past two hundred, as a growing population struggles to recover from slavery and colonialism while continuously servicing massive international debt.Haiti's current resource crisis did not occur in isolation nor did it originally spring from mismanagement of resources on the part of the majority of Haitians, but rather the international pillaging of Haiti's extraordinary fertility began with slavery and colonialism, and continues through the more subtle and insidious forces of economic globalization.

Agricultural exportation using slave labor was only the beginning of the massive exportation of Haitian soil, first to Europe in the form of produce, and later to the sea from the deforested mountains. Haiti suffered the unique and economically devastating punishment of having to pay reparations to French slave-owners after the revolution of 1804, a struggle that represents the only successful slave revolution in history. In 1825 the Haitian people were forced to assume a debt to France of 90 million gold francs (equivalent to US $21.7 billion today) as “reparations” to their former “owners” in return for diplomatic recognition and trade. It took Haiti over 100 years to pay off the debt.To make first payment the government had to close the few public schools that existed at the time, in what is called the “hemisphere's first case of structural adjustment”. In addition to preventing the newly independent nation from establishing a basic infrastructure for development, these payments to France contributed to massive deforestation, as Haiti's trees were exported to service the debt.

Through colonialism and economic manipulation, Haiti's resources were used to build Paris, not Port au Prince. Haiti's fertile soil was mined to provide the French with luxury imports of rum and coffee, while the majority of Haitians lived on the brink of starvation.

The other major cause of deforestation is poverty, much of which can also be traced back to international debt. The lack of electricity infrastructure and inability to afford gas measn that wood is the primary source of cooking fuel, and as a result only 3.5% of Haiti's forests remain intact, leading to soil erosion and reduced fertility for farming.

Haiti is the only nation in the Western Hemisphere in which the majority of citizens subsist as small farmers. Over 60% of its 8,000,000 habitants live in rural areas and two-thirds of the workers are employed in agricultural production. Haitian agriculture is practiced by approximately 600,000 small farmers using an average surface area of 1.8 ha. Yet, 80% of these farmers cannot satisfy the basic food needs of their families and the majority of producers depend on agriculture for less than half of their family revenue. In the past decade, per capita food production in Haiti has dropped 20% forcing the country to import 54% of its food supply. Haiti's health indicators are the worst in the region with a life expectancy rate hovering around 53 years of age and the incidence of childhood malnutrition is severe.

One of the root causes of poor health in Haiti is lack of sanitation services. Only 16% of rural Haitians have access to adequate sanitation facilities, by far the lowest coverage in the Western Hemisphere.Diarrhea and other infectious intestinal diseases cause 5% of all deaths and 15% of deaths in children under five.Acute diarrheal disease is the #1 health problem of Haitian children under age five.

Given the severity of the sanitation problem in Haiti and the implications for human health and the environment, there is a need for innovative solutions that can address these problems through interdisciplinary research and community-based implementation.