Ecological sanitation for sustainable sanitation

2.6 billion people in the world do not have access to improved sanitation facilities. Most of them are from South Asia and Sub-Saharan Africa.

In the race of accessing the facilities, a lot of pit latrines or improved pit latrine have been constructed behind they are cheaper ,thus easy to promote in low income areas. However, there remains a high potential risk of contaminating the ground water which is source of drinking water for millions.

Practical Action Nepal is therefore promoting ecological sanitation (ECOSAN) toilets in its EC supported project, Strengthening Water, Air, Sanitation and Hygiene Treasuring Health (SWASHTHA). The project is taking place in 21 communities targeting urban poor of four municipalities (Bharatpur, Butwal, Gulariya and Tikapur) in Nepal. The primary objectives of promoting ECOSAN toilets are:

1. Reducing the health risks related to sanitation, contaminated water and waste

2. Improving the quality of surface and groundwater

3. Improving soil fertility

4. Optimising the management of nutrients and water resources

The collection system of ECOSAN toilet is different with the other conventional and modern flush cistern toilet. In this toilet, faeces and urine is collected separately.

Ecosan toilet with different collection areas for urine and faeces

Urine collection tank

Nutrients in the urine are easily assimilated by plants and vegetables. However, the urine is diluted by adding water so it doesn’t burn the vegetation.

Using diluted urine to provide nutrients to crops

Similarly, faeces contains nutrients but there is a high risk of the presence of pathogens. Therefore, faeces can not be used directly as urine. Elimination of harmful pathogens in the faeces can be achieved by dehydration. That is why the importance of diverting the urine is dominant here. The entire process of dehydration of faeces takes about six months to one year. Then it can be used as compost.

It was believed traditionally that faeces has more nutrient value. However, the analysis of urine and faeces reveals that urine has significantly more nutrients than faeces. Urine is rich in nitrogen, phosphorus and potassium and can be used in agriculture as well as horticulture. The amount of urine collected from one person during one day is sufficient to fertilize one square metre of land. Urine collected from 30 persons for one year is sufficient to fertilize one hectare of land.

Description Unit Urine Faeces
Volume Litre per person per day 1.4 0.15
Nitrogen Gram per person per day 11 1.5
Phosphorus Gram per person per day 1 0.5
Volume Litre per person per year 500 56

Advantages of ECOSAN:

1.It requires less water than in the flush cistern toilet, where flushing is necessary after each urination and defecation.

2.It does not contribute to pollution. Both urine and human faeces are collected safely. It pollutes neither surface water nor ground water.

3.Separately collected urine and human faeces can be used as natural fertilizer. These natural fertilizers can be easily assimilated by the plants.

4.Improvement of health due to safe and hygienic sanitation.

There are a few limitations in promoting ECOSAN, however:

1.Users need to be aware how to use ECOSAN toilets. Faeces needs to be kept dry as far as possible.

2.People have to handle faeces. Therefore, people need to be educated that faeces is not waste but is a useful resource. Further, people need to be aware of using the compost of faeces and the proper use of urine.

3.The faeces compost needs to be handled carefully for health reasons.

4.There is a cultural barrier in terms of handling human waste

Material cost of an ECOSAN Toilet up to plinth level or pan level is about 8000 rupees (£64). The structure of the toilet can be built with locally available materials like bamboo, wood, boulders, mud etc.

One Response to “Ecological sanitation for sustainable sanitation”

  1. Kestutis Says:

    That seems a little srntage. Struvite crystals can be dissolved by acidifying the urine. But oxalate crystals are insoluble in water, so they are managed with diet, not normally any pH change.

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