Ecological Sanitation System : A Practical Approach

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Volume 91, September 2010 1

Planning and Designing EcoSan System with Vermi-composting forVillage Vidgaon in India

S B Nimbalkar, Non-member

P H Sawant, Non-member

R A Hegde, Non-member

The present paper deals with planning and design of ecological sanitation (EcoSan) toilets for a village.Sanitation is a critical issue as it is linked to both human health and dignity. EcoSan offers a solution to sustainable sanitation provision as it aims at providing improved sanitation by sanitizing the excreta and re-using it in agriculture. The objective of the project is to study the existing sanitation system of village Vidgaon also to identify the difficulties in use of present sanitation system. The aim is also to change the attitude of people and encouraging them to consider human waste as a valuable resource. The various methods of ecological sanitation system were studied and a new system of vermiculture composting toilet is suggested for the village Vidgaon in Jalgaon District of Maharashtra State. It is found out that the suggested system is beneficial

in terms of finance also to the village. This can be a role model for the ‘Nirmal Gram Puraskar’ given by Ministry of Rural Development, Government of India.

Keywords : Ecological sanitation; Vermiculture; Composting; Human excreta; Urine nutrients; Recovery

INTRODUCTION

Poor sanitation is leading directly to a decline in the qualityand quantity of available water resources, and the problemis now finally being treated with a greater degree ofseriousness than ever before.

Ecological sanitation (EcoSan) can be an approach to

improve sanitation and recovery nutrients from humanexcreta and urine. Ecological sanitation regards humanexcreta as a resource to be recycled rather than as a wasteto be disposed off. Recycling returns nutrients to soils andplants reduce the need for chemical fertilizers and restoresgood soil organisms to product plants. EcoSan representsa new basic understanding of wastewater handling in whichfaeces and urine are not considered as pollutants but insteadas useful resources.

The idea that human excreta are wastes with no usefulpurpose is a modern misconception. It has led to thedevelopment of socalled ‘drop and store’ or ‘flush and forget’sanitation solutions, where precious drinking water is usedto transport excreta into the water cycle misusing Indianrivers, oceans and aquifers as a sink for untreated waste.Ecological sanitation (EcoSan) regards human excreta asa resource to be recycled rather than as a waste to bedisposed off. According to reports, around 2.6 billion ofthe 6 billion people on the planet have no access to anyform of basic sanitation. Sanitation is a critical issue as it islinked to both human health and dignity. Every day, over 2.5

billion people suffer from a lack of access to improvedsanitation and nearly 1.2 billion people practice opendefecation, a staggering number, according to a report bythe WHO/UNISEF joint monitoring programme for watersupply and sanitation. At current trends, the world will fallshort of the millennium sanitation target by more than 700million people3. This was highlighted during the World

Summit on Sustainable Development in Johannesburg, 2002,where the existing Millennium Development Goals (MDG’s),adopted by the UN in New York in September 2000, wereexpanded to include the sanitation target of halving theproportion of people without access to sanitation in 1990 bythe year 2015.

EcoSan system enables the complete recovery of all nutrientsfrom faeces, urine and grey water to the benefit of agriculture,and the minimization of water pollution2. EcoSan systemsoffer appropriate and sustainable solutions for differentcircumstances and demands. They permit acceptable andaffordable sanitation for poor and rural areas, as well as for

high-income areas and industrialized countries. EcoSan,however, this is not true. As long as the sanitation systemis environmentally and economically sustainable, it is knownas EcoSan system.

All in all, EcoSan represents a new basic understanding ofwastewater handling in which faeces and urine are notconsidered as pollutants but instead as useful resources.In nature, there is no waste. EcoSan offers a solution tosustainable sanitation provision as it aims at providingimproved sanitation by sanitizing the excreta and re-using itin agriculture. The purpose of sanitizing and re-using excretais to reduce contamination of the natural environment, such

as, rivers and ground water; it also ensures that the valuablenutrients in the sanitized excreta are used for food production.

S B Nimbalkar, P H Sawant and R A Hegde are with theDepartment of Civil Engineering, Sardar Patel College ofEngineering, Munshi Nagar, Andheri (West), Mumbai 400 058.

This paper was received on September 29, 2009. Written discussionon the paper will be entertained till November 30, 2010.



2 IE(I) Journal – EN

SPECIFIC REASONS

The village Vidgaon in Jalgaon District is selected as studyvillage for planning and design of EcoSan system. It is nearlyeight km away from Jalgaon city. The population of the villageVidgaon as per 2001 census is 2368, out of which male are

1225 and female are 1143. There are total 527 families livingin the village Vidgaon and 355 families are below povertyline. There are total 469 survey numbers in the village Vidgaon.

OBJECTIVES

The objective of the project is to study the existing sanitationsystem of the village. The objective of the project is also toidentify the difficulties in use of present sanitation system.The focus is on improving sanitation conditions and scopeof minimizing the risk of disease spreading during monsoon.The aim is to generation of income for the self developmentof village by selling the products, namely, fertilizers. The

aim is also to change the attitude of people and encouragingthem to consider human waste as a valuable resource.

METHODOLOGY

The methodology involves establishing a new system forecological sanitation. Methodology includes study ofvermicomposting for design of new ecological sanitationsystem. It also includes the preparation of detailed designand engineering drawings and also preparation of the

estimates for traditional sanitation system and ecologicalsanitation system and their comparision. The situation ofthe water supply and sanitation in the village was collectedfrom village panchayat and from households.

Planning Coverage

The detailed survey of the village Vidgaon and its surroundingwas carried out. The population data and the village mapwere collected from the village panchayat. Ninety percent ofthe total population was doing open deification. The situationof the water supply and sanitation in the village was foundout. Their were ninenty five percentage of the total populationwere doing open defecation. The information was collectedfrom village panchayat and from households. A study wasdone on the different types of Sanitation facilities that areavailable. The engineering drawings of common toilet thatare feasible for the conditions in the village are prepared.

LIMITATIONS OF CONVENTIONAL SANITATION SYSTEM

Figure 1 schematically illustrates the main limitations ofconventional sanitation systems, that include

♦Unsatisfactory purification or uncontrolled discharge;

♦ Pollution of water bodies by organics, nutrients,hazardous substances, pathogens, pharmaceuticalresidues, hormones, etc;

Figure 1 Limitations of conventional wastewater management system




♦Severe environmental damage and eutrophication of thewater cycle;

♦Consumption of precious water for transport of waste;

♦ High investment, energy, operating and maintenance

costs;♦ Loss of valuable nutrients and trace elements containedin excrement through their discharge into water bodies;

♦ Impoverishment of agricultural soils, and increaseddependence on chemical fertilisers;

♦ Predominance of combined central systems, resultingin problems with contaminated sewage sludge;

Also, where there is no sewer network to transport thesewage, and also no access to take out the sludge throughvacuum vehicles, which are provided by Municipal

Corporations, poor practices are adopted like removal of thesludge manually. This seems very inappropriate, that thehuman excreta is removed by another human manually.Removal of human excreta is prohibited in India, but stillthere are these poor practices. Removal of human excretaalso imports health hazards, poor environmental impacts inthe nature. Figure 2 and Figure 3 show two photographs,describe the storey of the poor practices.

ADVANTAGES OF ECOSAN CONCEPT

To overcome drawbacks of the so called ‘end-of-the-pipe’sanitary systems and manual removing systems, which are

based on the modern misconception that human excretaare simply wastes with no useful purpose and must bedisposed of, and in order to meet the Millennium DevelopmentGoals and achieve sustainabili ty in the field of sanitation anew paradigm is needed3. Ecological sanitation is this newparadigm in sanitation that recognises human excreta and

water from households not as a waste but as resources thatcan be recovered, treated where necessary and safely usedagain. In this way, they help preserve soil fertility andsafeguard long-term food security, whilst minimizing theconsumption and pollution of water resources.

EcoSan is a holistic approach to sanitation and watermanagement, representing a break with the too often poorlyperforming end-of-pipe technologies of the past, andrecognising human excreta and domestically used water asa resource that should be made available for reuse. As anintegrated alternative, a hallmark of ecosan is itsinterdisciplinary approach that goes beyond the narrowdisciplines of domestic water supply and technologicalconsiderations to address issues such as agriculture,sociology, hygiene, health, town planning, economics andsmall business promotion, institutional administration, andso on. Advantages of ecosan systems are summarized asfollows.

♦ Improvement of health by minimizing the introduction ofpathogens from human excrement into the water cycle;

♦Promotion of recycling by safe, hygienic recovery and useof nutrients, organics, trace elements, water and energy;

♦ Resource conservation, through lower waterconsumption, substitution of chemical fertilisers andminimisation of water pollution;

♦ Possibility to integrate on-plot systems into houses,increasing user comfort, and security for women and girls;

♦Contributes to the preservation of soil fertility;

♦ Improvement of agricultural productivity and hencecontributes to food security;

♦ Promotion of a holistic, interdisciplinary approach(hygiene, water supply and sanitation, resourceconservation, environmental protection, urban planning,agriculture, irrigation, food security, small-businesspromotion,);

♦Material-flow cycle instead of disposal.

TECHNOLOGIES IN USE FOR ECOSAN SYSTEMS

Dehydrating Toilets with Urine Diversion

This technology is also called dry urine diversion toilet. In adehydrating toilet, the contents of the processing vault aredried with the help of heat, ventilation and the addition of drymaterial. The moisture content should as quickly as possiblebe brought down below 25%. At this level there is a rapidpathogen destruction, no smell, and no fly breeding. Theuse of specialized collection devices, which divert urine forstorage in a separate container, allows the faeces to bedehydrated fairly and easily (Figure 4). Since urine contains

most of the nutrients, it may be used directly as a fertilizerwithout the need for further processing. It is generally difficult

Figure 2 Manual removal of human excreta

Figure 3 Manual removal of human excreta




to dehydrate excreta without urine diversion, although inextremely dry climates2.

A Waterless Toilet with One or Two Vaults

The toilet is built entirely above ground with the processing

chambers placed on a solid floor of concrete, bricks or clay.The floor is built up to at least 10 cm above ground so thatheavy rains do not flood it. The processing chambers arecovered with a squatting slab that has two drop holes,footrests and a groove for urine. At the back there are twoopenings, for the removal of the dehydrated material. Theseopenings are kept sealed until it is time to empty one of thechambers. Before the vault is used for the first time, thehousehold members cover the floor with a layer of powderedearth. The purpose of this earth is to absorb moisture fromthe faeces and to prevent them from sticking to the floor.After each use people sprinkle two bowls of ashes over thefaces. The ashes absorb moisture, neutralize bad odours

and make the faeces less attractive to flies. Urine drainsaway through the groove in the slab and collects in a jarbehind the toilet. The urine or the urine-soaked ashes areused as a fertilizer. The first vault can be used for about twomonths by a household of 5-10 persons. When it is two-thirds full, someone in the household levels the content witha stick. A person then fills the vault to the brim with dried,powdered earth, and seals the vault. All openings are tightlyclosed with lime mortar or clay. The dehydrated faeces, nowodourless, are used as fertilizer. These types of toilets arecommonly used in Vietnam2. In India, vault type toilets areused in Ladakh, which is a dry highland region in the western

Himalayas.

Composting Toilets

Composting is a biological process in which, under controlledconditions, bacteria, worms and other types of organismsbreak down organic substances to make humus, a rich,stable medium in which roots thrive. The humus producedis an excellent soil conditioner, free of human pathogenswhen the right conditions are achieved and adequate retentiontime is allowed in the digester. Odours, if any, can beextracted directly out above the roof through a ventilationsystem. A composting toilet tries to achieve optimal

conditions for biological decomposition. This means thatsufficient oxygen should be able to penetrate the compostheap to maintain aerobic conditions, the material in thecomposting vault should have a moisture content of 50.60%

and the temperature of the composting vault should be above15°C. A variety of organisms contribute to the breakdown ofthe material in a composting toilet. They range in size fromviruses, bacteria, fungi and algae to earthworms and insects.They all play a major role in mixing, aerating, tearing apartand breaking down the contents of the pile in the toilet

processing vault.

The composting toilets were practiced in Norway, Swedenand Mexico. In India, the concept of use of earthworm inEcoSan toilets is proposed in this study. It seems a goodoutcome to earthworms in the toilet. If the environment isfavourable for them they will multiply, burrowing holes throughthe compost heap, eating odorous organic matter andthereby converting it into rich organic soil.

Vacuum Systems

The key elements used in vacuum toilets are vacuum urinals,

vacuum conductions and pumping station. The advantagesof this technology are saving water, concentrated black watercollection, possibility of anaerobic decentralized treatment3.This system is manufactured by Roediger (Figure 5).

Anaerobic Treatment with Bio-gas Production

Bio-gas originates from bacteria in the process of bio-degradation of organic material under anaerobic (without air)conditions. The natural generation of biogas is an importantpart of the biogeochemical carbon cycle. Methanogens(methane producing bacteria) are the last link in a chain ofmicro-organisms which degrade organic material and return

the decomposition products to the environment. In thisprocess bio-gas is generated, a source of renewable energy5.The general model for degradation of organic material underanaerobic conditions operates principally with three maingroups of bacteria, such as, fermenting, acetogenic andmethanogenic bacteria, which degrade organic mater in fourstages, namely, hydrolysis, fermentation, acidification andmethane formation

Aqua Culture

The wastewater treatment by aquatic plants and fish withnutrient recyling by human consumption is known as aqua

culture. This technology offers high quality protein at lowcost. This technology is predominantly used in Asiancountries. The average fish production of 1t/ha/yr to 6 t/ha/yrcan be achieved using this technology.

Figure 4 Urine diversion type toilet Figure 5 Vacuum system type toilet




Constructed Wetlands

This treatment of wastewater or greywater is effective in theremoval of BOD, TSS, pathogen and nitrogen. The effluentcan be reused for gardening. This technology is aestheticallyappealing all over other technologies. Combined wastewater

treatment and bio-fuel production from willow plantations ispossble with wetlands. This is very cost and energy effective.Constructed wetlands are common practices in India fortreatment of wastewater especially industrial effluents3.

Each of the above technology has its application as per theprevailing site conditions.

PLANNING OF PROPOSED ECOSAN SYSTEM

The detailed survey of the village and its surrounding wascarried out. From the the population data and the villagemap, it is found that, about 90% of the total population was

doing open deification. From the survey, a location on thevillage map is finalized and a new system is designed forthis location and for 100 people.

Basic Data for Dimensioning and Layout

1. 95% of the total number of villagers uses the toilet fordefecation and urination.

2. Villagers use toilet one and half times for urination.

3. Human waste : urine 500 l/year ≈ 1.4 l/day; faeces50 l/year ≈ 0.14 l/day

Technology Suggested

To overcome unhygienic conditions related to malfunctioningof the main wastewater disposal facility and to meet theneeds of extension of the locality, a sanitation conceptcomprising the treatment/reuse of human excreta withearthworm composting.

Composting Toilets

The technology suggested for this particular project is thevermi composting type toilets. Vermicomposting is theprocess by which organic materials are converted into humuswith the use of specific types of earthworms that breakdownthe organic materials. The earthworm species, Eisenia fetida and Eisenia andrei are most commonly used for thevermicomposting. They derive their nourishment form micro-organisms that grow upon the organic materials. At the sametime, they promote further microbial activity in the residualsso that the feacal matters or ‘casts’ that they produce, ismuch more fragmented and microbial active than what theearthworms consume. During this process, the importantplant nutrients in the organic material, particularly nitrogen,potassium and calcium are released and converted throughthe microbial action into forms that are much more solubleand available to plants than those in the parent compounds.

The best kinds of worms for composting are ‘red worms’, or‘red wigglers’. They are often found in old compost piles, but

are different from the earthworms would normally find in theground. These worms have a big appetite, reproduce quickly,and thrive in confinement. They can eat more than their ownweight in food every day. Vermiculture can be a lucrativeeconomic activity for rural women.

Design of Proposed EcoSan System for a VidgaonVillage

Volume of Urine Tank

Number of villagers to defecate at the toilet is 95.

Number of villagers go for urination = 95 × 1.5 = 142.5

Daily volume = Number of villagers × urine collected/day

= 142.5 × 1.4 l/day = 199.5 l/day = 0.1995 m3 /day

A storage time of one month is required during warm season

to sanitize the urine with daily volume of 0.1995 m3

/day.

A urine tank of volume 6 m3, ie , 6000 l should be installed asstorage capacity.

Volume of Faeces

Number of villagers to defecate at the toilet

= 100 × 95% = 95 villagers

Yearly volume = Monthly volume × 12 months

= 399 × 12 = 4788 l/year = 4.788 m3

A storage time of three months is required during warmseason to compost the faeces with daily volume of 0.0133m3 /day. A vermi composting bed volume of 5 m3, ie , shouldbe installed to accommodate this loading.

Provision of Toilet Block

The toilet block in the village for ecological sanitation is suchplanned that to accommodate the numbers of persons at atime. There is a provision of total ten toilet rooms, out ofwhich, six toilet rooms for male villagers and four toilet roomsare for female villagers. The outlet of the each toilet room isconnected to a main pipe through branch pipes and then tothe collection urine tank and to the vermi composting bed.

Dimensions for Vermi Composting Bed

Total volume of faeces yearly = 5 m3

Number of parts = 2 (for male and female)

Volume of faeces/cubicles = 2.5 m3

As the compartments should not be fully filled (filled level =75%) and to 10% is allowed extra for security.

Thus, size of vermi composting bed suggested is 1.0 m ×

2.0 m × 1.5 m depth.




Squatting Pan

The most important part of ecological sanitation toilet is typeof squatting pan to be used. Squatting pan is used to avoidmixing of urine and faeces. The squatting pan for the villageVidgaon is used as shown in Figure 6. The squatting pan is

specially made for urine diversion toilets. The squatting panhas three parts, one for urine collection, second for faecescollection and third is for fresh water.

Manure produced through vermi-composting and urinefertilizer can be sold in the local market or to local farmersand awareness can be made that the human waste is notthe waste but is a resource.

From planning of ecological sanitation system at the village

Vidgaon, Jalgaon, it is found that, the villagers were usingopen defecation system, which is commonly observed allover in rural India. The places are outside of the village andmen and women defecation places were at the differentlocations. As the places are outside, it was the problem inthe night time especially for the women in the village. Also,they contracted diseases mainly during the monsoonseason. There are cases of rise in waterborne diseasesduring monsoon season, this may due to the mixing humanexcreta with the groundwater, which goes to wells. This isavoided after proper sanitation system like EcoSan.

REFERENCES

1. ‘ Joint Monitoring Programme for Water Supply and Sanitation,Progress on Drinking Water and Sanitation : Special Focus on Sanitation.’WHO/UNISEF , 2008.

2. ‘Ecological Sanitation.’ Department for Natural Resources and the Environment Swedish International Development Cooperation Agency.’1998.

3. Christine Werner, Heinz-Peter Mang, Florian Klingel and PatrickBracken. ‘Ecological Sanitation Programme, Division 44 - Environmentand Infrastructure.’ Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), Germany.

4. Site visits in the slums where no sewer connection facility is available.

5. ‘Innovative Ecological Sanitation Network India (IESNI).’ Training Material on Bio-gas Sanitation Version 1, Ecosan Services Foundation (ESF) and Seecon, Gmbh.

Figure 6 Urine diversion squatting pot

The dimensions provided at ecological sanitation systemtoilets at village Vidgaon are 940 mm × 415 mm × 90 mm.The diameter of hole for entry of faecel matter is the maximumand is 180 mm.

CONCLUSION

A new system of ecological sanitation with vermi-compostingis proposed. The cost comparison is done betweenecological sanitation system and conventional sanitationsystem is carried out and from the analysis, it is observed

that cost of ecological sanitation system works out to becheaper with respect to conventional sanitation system. Thetotal over all saving is 10%.

Documents

Ecological Sanitation System : A Practical Approach