Down to Earth, Vol 10, No. 19, February 28, 2002

With kind permission of the Director of the Centre for Science and Environment, New Delhi,India and the author of the article: Sunita Narain

The flush toilet is ecologicallymindless

Think about it.

SUNITA NARAIN

While attending the Stockholm WaterSymposium a few years ago, my colleague,Anil Agarwal, and I were invited to a banquetby the king of Sweden. But instead of diningin splendour we were checking out toilets insome remote parts of the city. I was not tooconvinced of our mission. We opened thehatch of "alternative" toilets bins, where thefaecal matter is stored before composting.We were regaled with information about howurine could be separated in the toilet andused directly for agriculture. Our friend, UnoWinblad, toilet crazy like Anil, then took us tosupermarkets in Stockholm city where therewere a range of toilets — from water-savingto electric and of course, urine separatingtoilets. Anil, who hated shops, was delighted.And I began to understand the links.

The flush toilet and the sewage system —

which I always believed embodied personalhygiene and environmental cleanliness — area part of the environmental problem and notthe solution. I began to understand from ourresearch that this technology is quite simplyecologically mindless.

Consider the large amount of clean water thatis used to carry even a small quantity ofhuman excreta. In India, flushes are designedto be particularly water-wasteful. So witheach flush, over 10 litres of clean water goesdown the drain. We build huge dams andirrigation systems to bring water to urbanareas. This water which is flushed down thetoilet goes into an equally expensive sewagesystem, all to end up polluting more water —invariably our rivers and ponds. Most of ourrivers are today dead because of thedomestic sewage load from cities. We haveturned our surface water systems into opensewage drains.

This heavy use of surface water is leading togrowing conflicts between urban and rural

users and also to overexploitation. Moreover,the discharge of domestic sewage is leadingto heavy pollution of rivers and urbangroundwater aquifers.

The present strategy is to invest in huge riverclean up programmes like the Ganga ActionPlan, the Yamuna Action Plan or the NationalRiver Action Plan to treat sewage. Theseexpensive river action programmes aresanitary engineers’ dreams. The aim is todivert sewage, which earlier flowed directlyinto the river, to a treatment facility. Thissewage, incidentally, comes from the flushtoilets of the rich, not the poor.

This is what Anil called the political economyof defecation. The more water you use, themore investment is needed to clean it up.

The political economy of sewer systems issimply atrocious for developing countries.Hardly any poor city is able to recover itsinvestments in sewer systems. As a result,the users of these sewer systems get asubsidy. But almost all users in poor cities arethe rich. Thus, sewers only lead to a subsidyfor the rich to excrete in convenience. Thepoor always remain the ‘unserved’ in thiswaste disposal paradigm. In addition, thegovernment has to invest in sewagetreatment plants whose costs are again rarelyrecovered from the rich users of flush toilets.

Sewers cost the earth

It is virtually impossible for governments tocatch up with the targets of building sewagetreatment plants. Government programmeschase targets hopelessly and remain milesbehind the volume of sewage beinggenerated. In a rapidly urbanising situation,

the city would soon outgrow the sewagetreatment capacity created at a high cost.Further investments would be needed all overagain.

Understand the political economy ofdefecation

Take Delhi, as a typical instance. Yamuna isDelhi’s main sewage drain. Yamuna entersDelhi at Wazirabad — where the city drawsits water supply — and after this an estimated1,800 million litres per day (MLD) of untreatedsewage flows through 18 drains into the river.In the last four decades, the total sewageoutput has increased rapidly. Untreatedsewage has grown even faster. In 1999, theCentral Pollution Control Board estimatedthat Delhi produces over 2,547 MLD ofsewage of which only 885 MLD is collectedthrough the sewage network for treatmentand the bulk — over 75 per cent flows intostormwater drains and then into the river. Bylate 2000, treated sewage had increased to1,333 MLD as had the quantity of sewage —still over 50 per cent of the city sewage wasdumped into the river. By 2005, Delhi plans totriple its present sewage treatment capacityat a cost of Rs 750 crore. But this will still beless than what is needed.

Paradoxical chase

It is an ironic situation. Even if Delhi builds allthe sewage treatment plants, it will still nothave the sewage to treat. Why? The city’ssewage drains are choked and silted. Thegovernment admits that the present capacityof the sewage treatment plants is not beingutilised and when it builds new treatmentfacilities, sewage never reaches these plants.

On the other hand, sewage from thesechoked and broken lines is diverted tofunctioning lines and, as a result, thetreatment plants at the end of these lines areoverloaded leading to untreated sewageflowing into the river. While some plants areoverloaded, others are underutilised. The bill

to refurbish the sewers is around Rs 500crore, according to the government. Over andabove this is the capital cost of the newsewage treatment plants.

Moreover, this is the cost of maintaining andrunning sewage plants and ensuring that thereleased effluent meets quality standards.Even if the government were to bear the fullcapital costs of sewage treatment plants, fewurban municipalities have the financialresources to bear the expensive operatingcosts. As a result, sewage treatment plants,even when built, often lie idle.

In urban areas, drinking water is a smallcomponent of the total water use. It issewage and other waste disposal needs thatrequire maximum water input. This hugedemand for water for our cities comes at veryhigh political cost as conflicts between urbanand rural users for water are reachingflashpoint

A tale of two cities

The water culture of people is an importantindicator of their level of civilization. Take thetwo ancient cities, Rome and the town of Edo,which grew into the mega-metropolis ofTokyo. The people of Rome brought theirdrinking water with the help of longaqueducts, which today are regarded asarchitectural marvels of the bygone Romancivilisation. But the people of Rome lived onthe banks of the river Tiber. They didn’t needto bring water from afar. Unfortunately, theydid not know to dispose of their humanwastes and like the modern Westerncivilisation they ended up polluting the river,thus being forced to go far in search of cleanwater. This makes Roman aqueducts not asymbol of intelligence but one of greatenvironmental stupidity.

On the other hand, Edo, which too wassituated on several streams, ensured that allits human wastes were collected andreturned to the farmlands. Its neighbouring

rivers remained clean and it tapped its waterfrom them through an extensive piped watersupply.

But today we are all children of Rome and notEdo. We have turned our backs to ourwaterbodies and if we don’t have money toclean our mess, then we will have nothing butpolluted waters.

Paying "full costs"

Worse, the political economy of defecation issuch that no democratic government willaccept the hard fact that it cannot "afford" toinvest in modern sewage systems for itscitizens. Instead, it continues to subsidise theusers of these systems, in the name of thepoor, who cannot afford these systems in thefirst place. The cost to build sewagetreatment plants is externalised through theseenvironmental programmes. The logicalpolicy would be to accept the cost and then toimpose differential pricing so that while therich pay for the cost of the capital andresource intensive sewage and wastedisposal technology, the poor pay for the costof their disposal system, which is invariablyunconnected to the sewerage system andhence low cost.

But this is easier said then done. The"socialist" framework in our country forcespolitical leaders to keep water and wastepricing affordable for large sections of urbanpopulations. In this situation, privateinvestment also looks for an easy way out.Their answer is to invest in water servicesand leave the costly business of cleaning upthe waste to government agencies.

In the meantime, the use of sewer systemswould have totally destroyed the aquaticecosystems in the developing world, posingenormous threats both to public health andaquatic biodiversity. In India, we don’t evenhave to look a few years ahead. We alreadysee the signs of this hydrocide. Literally, nosmall or medium river today is clean. Every

river that passes through a city or a townbecomes a stinking sewer.

Dirty sewers

Sewage systems are built to protect publichealth but badly managed sewers canbecome a serious health hazard. There canbe serious outbreaks of waterborne diseasesfrom:

• River pollution because of sewageoutfalls;

• Groundwater contamination because ofleaky sewer lines;

• Contamination of piped water supplysystems because of leaky sewer linesleading to infiltration of pathogens intodrinking water pipelines, especially whenthey do not have water, which is the casein many cities in developing countries asthey cannot provide water round theclock; and,

• Sewage backflows because of badlymaintained and blocked sewers orbecause of increasing use of non-biodegradable materials like plastic bags.

Sewers: a subsidy for the rich to excrete inconvenience

In the Indian city of Aligarh, sewer linesoverflow all the time. A study conducted bythe Aligarh Muslim University for the Centrefor Science and Environment found that 49-70 per cent of the households, depending ondifferent localities, complained of seasonal orpermanent waterlogging due to overflowingsewage drains. As a result, people haveraised the plinth of their houses to keep thesewage from flowing into their houses. This

has resulted in a huge market for earth — asmuch as 1,000 cubic metres per day —supplied today by numerous villages aroundthe city, which is destroying preciousagricultural land.

All this makes water-borne sewerage a wastedisposal paradigm that is extremelyexpensive because of its high economic,environmental and public health costs. Andas a result, it has very high political costs.

Going against the laws of nature

Sewer systems totally destroy nature’snutrient cycle in which nutrients collectedfrom the land should be returned to the land.With the use of sewers, this "waste" getsdumped into our aquatic systems. Therefore,while nutrients in food come from agriculturallands, sewage systems dump the nutrientscontained in human wastes into waterbodies.Over time, our agricultural lands get depletedof nutrients and need intensive artificialfertilisation. The lack of these micronutrientsnot only becomes a limiting factor in plantproductivity but the resulting lack of thesenutrients in human food becomes a threat tohuman health. By the early 1980s, Punjabhad large tracts of land with zinc, manganeseand iron deficiency. Ludhiana district, whichrecords the highest yields of many crops, wasalso recording the highest deficiencies ofmicronutrients. Though scientists still have tofigure out the health effects of consumingmicronutrient-deficient foodgrains, scientistsat the Postgraduate Institute of MedicalSciences in Chandigarh have found thatconsuming zinc- deficient foodgrains can leadto retarded growth, defective wound healingand carbohydrate intolerance.

Paradigm shift

Clearly we need to look for a cost-effectiveand non-sewerage paradigm of human wastedisposal. The capital-intensive, material-intensive urbanisation process of the Westworks only for rich countries, not poor

countries.

While our scientists think about going to themoon, the toilet is not in their vision at all.There is absolutely no thinking about theneed to find environment-friendly sewagesystems in our countries. We will needmassive investments in r&d for non-seweragealternatives. While investments in sewers runinto billions of dollars every year despite allthe problems they create, researchinvestments in non-sewage alternativeshardly exist.

Sewer systems totally destroy nature’snutrient cycle

In this context we need to learn from what ishappening across the world. There is agrowing concern for ecological sanitation andthis is giving rise to innovations from theconcept of sewer-less cities using newtechnological systems which use extremelylow amounts of water or no water at all, and,in which all the wastewaters and the solidwastes are recycled.

These modern systems are built on thetraditional science of recycling andcomposting human waste. But in a way thatuses the best of modern science andtechnology to "sanitise" waste and match theconvenience and public hygiene of themodern flush toilet.

Therefore, ecological sanitation is a paradigmthat we must explore in all earnestness. Butwe must make sure that the new technologiestake into account cultural constraints.Otherwise they are unlikely to succeed.

The most important issue is that these"alternative" technologies must be for the richand not just for the poor. If ecosanitationtechnologies are "cost effective" technologiesto serve the "unserved" poor, these will onlybe an interim alternative, one to be discardedas soon as people become rich. We have toremember that it is the rich person’s flush thatis the biggest environmental culprit today.

DROWNING IN HUMAN EXCRETA

Sanitation for urban India means buildingflush toilets and linking them to sewersystems. But the price of chasing this dreamis leading to an environmental catastrophe.MANOJ NADKARNI analyses our flush andforget mindset

"Don’t flush." M K Malhotra, a resident ofDelhi’s Vasant Kunj, has put this instructionon his toilet. Six members of his family usethis toilet at least three times a day and tenlitres of water goes down the drain with everyflush. In a water-scarce locality, Malhotra canhardly afford this basic sanitation practice. "Infact, it’s a luxury," he says.

Malhotra’s warning is apt. Flushing consumesmaximum amount of water in an averageurban household. An ever- increasing urbanpopulation — 25.8 million in 1901 to 285million in 2001 — has thrown up twoproblems: shortage of water and sewageoverload. Malhotra is still fortunate: more than80 per cent people in rural India do not haveaccess to toilets.

PARADOX OF A PARADIGM: lack ofsanitation spawns outbreaks; access to

flush toilets invites ecological catastrophe

Sources: Peter H Gleick, The World’s Water,2000-2001, p11; Abstract Volume, FirstInternational Conference on Ecological

Sanitation, November 5-8, 2001, p7;`Statusof water supply and waste

Human waste is nutrient rich

The urban-rural divide

Sources:water generation, collection,treatment and disposal in metrocities (1994-95), CPCB, August 1997, p32-33; Anon July1999, Drinking water, sanitation and hygienein India, NSSO, p40

"Sanitation is more important thanindependence," Mahatma Gandhi once said.It is been 55 years since independence andsanitation is still a neglected sector in India.Sanitation is available to 48 per cent of urbanand just 3.15 per cent of the rural population.As the Planning Commission pointed out inthe Ninth Plan, "While the provision ofdrinking water to urban areas in the countryhas improved over the years, the provision ofsewerage and drainage facilities has notreceived adequate attention."

Health costs

Providing water and sanitation facilities mayseem expensive, but the costs of notproviding are much higher. In Karachi,Pakistan, for example, a study found thatpoor people living in areas without anysanitation or hygiene education spent sixtimes more on medical care than people wholived in areas with access to sanitation and

who had a basic knowledge of householdhygiene. In India, rural people spend at leastRs 100 each year for the treatment ofwater/sanitation-related diseases. Accordingto the government of India, this adds up to Rs6,700 crore annually, which is just Rs 52crore less than the annual budget of theUnion health ministry’s and more than theallocation for education.

It is not as if these diseases appear out ofnowhere. People contaminate theenvironment and they are in turn infectedthrough the "pathogen cycle" (see flow chart:Deadly web). Breaking this cycle is thefunction of sanitation. In simplest terms,sanitation acts as a barrier between humansand disease causing agents. The barriers aregenerally physical, chemical or spatial. Theflush toilets and sewage systems aresupposed to provide all three: flushingphysically carries pathogen- bearing faecesaway from contact with us, the sewagesystem creates some space between the two,while chemical and other processes intreatment plants are used to destroy them.

Deadly web

How pathogens in excreta enter humans

Standard toilets and sewage systems aretaken for granted in middle and upper classhomes in urban India. The attitude is: flushand forget — out of sight and out of mind.However, what happens to the waste afterthe flush is pulled? After some treatment, itflows in our taps. Possibly, for middle andupper classes living urban environments with

artificially low water charges, there is nothingwrong with it, especially in the short term. Butwhen the whole picture is taken into account,the benign nature of sewage changesdramatically.

Urban sewage systems can be seen as alinear process. The act of flushing lets largeamounts of water physically push excreta anddiluted urine down and around the "s" seal ofthe toilet. Blackwater (wastewater whichbears human excreta) and grey (wastewaterfrom the bath, kitchens and sinks) are mixedwhen they leave a house. The pipe carryingthis wastewater joins pipes of other houses orapartment blocks and empties into themunicipal sewer. This relatively smalldiameter sewer joins other peripheral sewersand finally joins a large trunk sewage drain.More water is added to stop blocking ofsewage lines. Water to transport is pumpedand kept flowing. (But not too much water,since this would overwhelm the system.)These sewers keep the wastes flowing to asewage treatment plant. This treatmentinvolves removing the solids as sludge,getting rid of organic and inorganic pollutants,disinfecting it of pathogens and finally insome state of cleanliness, the treated water isreleased into the nearest river or sea. Thesolid sludge left is used either as landfill or asfertiliser. So far so good. At least on paper.

Overwhelmed by sewage

In reality things don’t work so well. Firstly,only a small percentage of Indian towns andcities actually have sewage treatment plants.The Central Pollution Control Board pointsout that out of 22,900 million litres a day(MLD) generated as wastewater, only 5,900MLD is treated — less than 3 per cent.

So where does the rest (untreated) with itsload of dangerous pathogens go? Oftenuntreated sewage is dumped straight intorivers or other surface bodies. Theenvironmental and health costs areenormous: our rivers and our children are

dying. This is because large amounts ofwater are being taken away from the riversand used to carry excreta. The ‘diluted’excreta is drained into rivers. Most Indiancities are based on river basins and usethese rivers as sources for drinking water andwaste disposal.

Sewage treatment is also expensive. TheMumbai-based Indira Gandhi Institute ofDevelopment Research (IGIDR) hasestimated that to provide wastewatertreatment in 10 large cities (population of 1.5million and above) it would cost Rs 1,400-1,600 crore depending on the technologyused for sewage management. The landrequirement in these 10 cities would be 1,137hectares. This estimate does not include theinfrastructure, which needs to be in place aswell as ongoing operating costs. Anotherassessment by the cpcb says that treatingsewage for 23 metro cities would cost Rs2,750 crore at 1994 prices.

No access

What is even more worrying is that a minorityof Indians, who have access to sewers,cause water pollution. According to NationalSample Survey Organisation’s 54th roundsurvey, 74 per cent of urban population usetoilets, but only 22.5 per cent are connectedto sewers and 35.2 per cent use septic tanks.

In Indian cities a large part of the populationlives in slums and peri-urban area and thesesettlements quite often have no "legitimacy"and are not factored in any urban sewerageplanning. Yet in a city like Mumbai, half of itsnearly 12 million residents are either slumdwellers or homeless. They occupy six percent of the city’s land, living in crampedsquatter areas with little or no access tosewage and sanitation facilities. When theyare included, often under pressure fromNGOs, the first thought is to build flushsystems and sewerage, which proves to beeconomically unsuitable. In a slum, up to 500people could share one toilet. Moreover, very

little thought is given to their upkeep. Forexample, in Delhi the mcd is theimplementing agency for low cost sanitationschemes including community toiletcomplexes. But these don’t work most of thetime.

Scavenging

The drive to do away with scavenging system— the practice in which toilets not connectedto sewers are manually emptied and cleaned— was an opportunity to bring in freshthinking into toilet designs keeping in mindIndian context. But this never happened.Rather, the government stuck to the flushtype latrines. With the passing of the 1993Employment of Manual Scavengers andConstruction of Dry Latrines (Prohibition) Act,the conversion of the so-called dry latrines towater seal pour flush latrines got underway.Up to March 2000, Rs 1,339.98 crore hadbeen spent on this scheme, states anappraisal report of the planning commission.Yet, less then eight per cent of the totalrecorded dry latrines were converted tosanitary ones till the first three years of theNinth Plan. To meet this huge target ofadopting water-intensive technology, thegovernment has to dole out the requiredmoney. Funds will be required to not only setup infrastructure needed, but to maintainthem, given the growing demand for flushtoilets.

Then money will be needed to build sewagetreatment facilities. Though industrial pollutionin rivers often gets prominence, humansewage is the biggest threat: 80 per cent ofpollution in Indian rivers is due to humansewage, says the Planning Commission. TheUnion ministry of environment and forests(MEF), in its Ninth Plan, fixed a target to setup sewage treatment facilities for 1,591 townshaving a population over 20,000, incoordination with Union ministry of urbandevelopment and state governments. Thequestion is where will the money come from?

The sewers in Delhi have lost 80 per cent ofthier carrying capacity due to age and poormaintenance. This means that only 20 percent of domestic wastewater is being treated,the rest flows directly into the Yamuna. In thecase of major river pollution abatementactivity like the Ganga Action Plan, only 13.7per cent of the targeted sewage treatmentcapacity has been created.

Constipated mindset

Already, the costs of treatment are not beingmet. An indication of this is the price of water.If all the water treatment were taken intoaccount in a city like Delhi, the price of waterwould be Rs 4.61 per litre. Instead, the DelhiJal Board is charging just Rs 1.99. Revenuegeneration is 43 per cent of production costsin Delhi. In Kolkata, it’s at a ridiculous 14 percent, in Nagpur, 48 per cent and for Pune, itis 49 per cent. This is just the cost of treatingwater to make it fit to drink; none of thesefigures are inclusive of the cost of treatingsewage, before putting it into the rivers.

Another important constraint to service peri-urban areas is that lower-cost technologiesusually require a much higher level of userinvolvement than conventional technology tofunction properly. Yet engineers, whotraditionally play a major role in theformulation of sanitation projects, often havelittle training or regard for the socialmechanics of projects, such as mobilisingcommunities and involving future users, andhave little patience for the sheer time it takesto address them.

The Planning Commission points out what itcalls the "vicious circle of circumstances" —due to economic non-viability of the urbansewage and sanitation, programmes have

failed to cover all the population and due toinsufficient funding, operation andmaintenance have failed miserably. Therehas to be a paradigm shift in the waysanitation policies are formulated. The newapproach would have to suit the social andgeographical factors of the region and beenvironmentally and economicallysustainable. But who will bell the cat

Sanitised for not, the writing is on thewall

NEW AGE APPROACH

We need to go back to the drawing board toreinvent a green toilet. If necessary, to goback to our past and find technologicalinnovations that are sustainable andequitable. So that every Indian can haveaccess to sanitation and still have clean waterto drink. The alternatives to the flush toiletsare emerging. These are beginnings of thenew approach of sanitation — sewerless andless water intensive

We need to go back to the drawing board toreinvent a green toilet. If necessary, to goback to our past and find technologicalinnovations that are sustainable andequitable. So that every Indian can haveaccess to sanitation and still have clean waterto drink. The alternatives to the flush toiletsare emerging. These are beginnings of thenew approach of sanitation — sewerless andless water intensive

it is time to go back to basics and examinewhat toilets and sewerage systems aresupposed to do. The point of all thesesystems is the safe disposal of human wastematter. Flush toilets and sewerage transferthe problem elsewhere; they are complicatedways of spreading pathogens away from theuser to the public at large. Toilets andsewerage can be split up into two, since therereally is no logical connection between thetwo, just a historical one. The safe disposal of

wastes can be undertaken in two ways:

Off-plot systems in which excreta arecollected from houses and then transportedaway. This is what the modern seweragesystem is. On-plot systems in which safedisposal of excreta takes place on or near thehousehold.

If sewerage and flush toilets are consideredindispensable, the way to reduce theirenvironmental and financial impact iscontrolling how much water they waste. Whatoptions are available to reduce water use insewage systems?

Back to nature

In the flush system, the water is used not justto clean the toilet bowl, but also to transportthe excreta. A family of five who uses a watertoilet contaminates more than 150 thousandlitres of water to transport 250 litres ofexcrement in one year. We must recognisethat:

• Water is a precious resource and shouldnot be used to transport faeces.

• Waste should be managed as close aspossible to its source.

• Faeces and urine are resources ratherthan waste products.

The first step is seeing our biological "waste"as resources. All organisms need nutrients togrow; plants get these nutrients from the soil.Sewage systems bypass the natural flow ofnutrients back to the soil and instead dumpthese nutrients into water. On an average, ahealthy person discharges 100 to 400grammes of faecal matter and 1-1.31kilogramme of urine per day, which hasnitrogen, phosphate and potassium.

So with this first step, toilets can be seen ascollection devices rather than methods ofgetting rid of wastes. The problem is cultural— a society is "civilised" if it has access toflush toilets; faeces and urine are used onlyby less developed ones. But if these cultural

blinkers are thrown away, progress can bemade towards solving the problem of pollutedrivers and groundwater, waterborne diseasesand the enormous cost of sewage treatment.

The second step is recognise that water is aprecious resource and should not be used totransport faeces. And since we know excretacontains dangerous pathogens, it makes verylittle sense to dilute pathogens in water. Evenif a small amount of pathogen-carryingmaterial is mixed with a lot of pure water, theresult is still a dangerous mixture. Unlesstreated properly, human waste is hazardouswaste and "civilised" society puts it intodrinking water sources.

The third basic principle is that waste shouldbe managed as close as possible to itssource. Ignoring this principle is one of thereasons centralised sewage systems are sounsustainable both financially andenvironmentally.

Sewerage tactics

One way to do this would be changesewerage tactics. The condominial seweragesystem was developed in Brazil as a low-costoption as they cost about 50-80 per cent lessthan standard systems. Households areconnected to small-bore pipes rather thandirectly to sewers. These smaller pipes meetup and connect to the main municipal sewer.Smaller bore pipes need less water and at farlower pressure, making an immediate savingsin the volume of water used to carry faeces.

Another possibility is decentralised effluenttreatment. A block of houses or a housingcolony can have its own sewage treatmentplant. Again this means that compared tocentralised systems, far less water is used,as wastes do not have to be transported veryfar. Treatment plants can be smaller in sizesince the volume of wastes they will deal withwill be comparatively small. Any sludgeproduced is used locally as fertiliser.

A high-tech system is to do away with water-

based sewerage and have vacuum-basedsewer system like the one developed inGermany. If these can be coupled withvacuum toilets there is virtually no need ofwater. The outflows from toilets, kitchens, andbaths are sucked by a local pump into ahousehold vacuum station, from where theyare sucked into a central treatment point.Vacuum sewer network can work up to a 4km radius with one vacuum station. Thecollected sludge can then be conventionallytreated or used in a biogas digester.However, these systems as yet areexpensive and energy intensive.

A place where this is being tried is a pilothousing project in Lübeck-Flintenbreite inGermany where an integrated system withvacuum toilets, vacuum sewers and a biogasplant for blackwater as well as greywatertreatment in reed-bed filters is underconstruction.

Flush facelift

Instead of focussing on the sewerage andtreatment plants, flush toilets themselves canbe modified to the amount of water they use.Low flush toilets that use just one litre perflush have been designed. Quite a largeamount of water can be saved andrecognising this, many cities, like LosAngeles, usa, are giving rebates to peoplewilling to change their toilets to low watersystems, and in some cases, provide themfree.

These possibilities make a large difference tothe problem of water pollution. But again theypresuppose sewerage lines, however small.On-plot sanitation solves this problem.

Toilets originally designed for ships andairplanes are now being adapted for houses.The vacuum toilets mentioned earlier alsoreduce the amount of water. Electricincinerator toilets fall into this category wherethe faeces and urine mixture is dried byelectric fans and then burnt.

Of low-tech versions the standard on-plotsolution seems to be pit latrines. These aremerely holes dug into the ground andcovered with superstructure that contains thetoilet seat or pan. When the pit is full, it iseither emptied or another pit dug and thesuperstructure moved to it. The old site with atopping of soil is suitable for growing trees.Instead of a straight drop, an "s" bend isattached just below the toilet pan, a waterseal can be included which cuts off most ofthe odours. This is basically a simplifiedversion of the septic tank. In terms of theenvironmental impact, both pit and septictank toilets pose risks to groundwater. The usEnvironment Protection Agency has alsoexpressed concern about the amount ofgroundwater contamination that is caused byseptic tanks: they pose the greatest risk togroundwater in the us.

In the desperate race for environmentalsanitation, more radical designs are emergingwhich take ecological thinking to its logicalconclusion. Why not then just get rid of thewater? This is "ecological sanitation" orecosan for short, works on the principle Don’tmix faeces, urine and water. One need notlook towards other countries for successfulecosan design. In India, people in Ladakhhave been using such toilets for centuries(see box: Return to nature). Modern versionsof ecosan have also been tried and tested inIndia too (see box: Thinking clean).

Thinking clean

Ecosan toilets experiments in Kerala

Paul Calvert

Paul Calvert, a Kerala-based ecologicalsanitation expert, has proved that ecosanapproach can work in areas where water isscarce. In 1995, he built his first such ecosantoilet in a coastal village of Kerala. At thattime, 80 per cent households of the villagehad no latrines. Moreover, at least 50 percent of families were consuming water that

was contaminated due to open- airdefecation. However, the main impetus forCalvert was to provide women with someprivacy.

Since the water table of the area was quitehigh and prone to tidal flooding, building pitlatrines was not considered feasible.Moreover, building a sewerage system wasout of the question. Therefore, the best optionwas to build ecosan toilets.

Calvert’s ecosan toilet consists of a slab builtover two vaults. The slab has a hole overeach vault for the faeces to drop in and afunnel-like device to collect the urine.Between the two holes is a small drain overwhich anal cleaning takes place. The analcleaning water and the urine is togetherdrained into a plant bed.

Paul’s design: the compost is removed fromthe hole, while the urine is used to grow fruittrees

After each use, a small amount of ash issprinkled down the faeces hole to facilitatethe drying process. The two holes are usedon a rotational basis for six- months. Beforeuse, each hole is covered with straw tofacilitate decomposition. After six months, thedecomposed faeces is used as a soilconditioner.

Though these ecosan toilets are aseconomical as any other sanitation system,Calvert declines to comment on the cost."Many people judge things by the cost of thehardware. I want to promote the approach,not the hardware cost," he says. He has builtecosan toilets in other countries as well. Hissystem can be used in high water tableareas; dry, water scarce areas; rocky sitesand flood plains.

The nutrient loop

Urine is nearly sterile. Faeces, which is 10times smaller in volume than urine, containmost of the pathogens. If the two are keptseparate, urine can be directly used as

fertiliser while faeces can be sanitised andused as soil conditioner. This is why ecosanis described as "closing the loop". We eatplants that get nutrients from the soil. Weurinate and defecate and return the nutrientsback to the soil.

The German-designed vacuum toilet

Ecosan works by separating the urine andfaeces at source and putting both the urineand faeces back into the local nutrient cycle.Designing a toilet pan where the urine andfaeces go in different directions ensures this.The faeces drop straight down in a smallstorage chamber made of concrete or otherimpervious material. The urine goes to a tank.The faeces is stored and allowed todecompose by a process of aerobicdigestion. Ash or other organic absorbingmaterial like sawdust is used to cover thefaeces to aid in the drying out process. Timeallows heat, given of by decomposition, andnormal soil bacteria to kill all the diseasecarrying organisms. Within six months, thefaeces is reduced to humus.

The process used to sanitise faeces can besimply split up into two types; with urine it is acomposting, without; a dehydrating process.In both, the action of time and soil microbesdestroys pathogens.

On the block

Modern ecosan toilets are already in usewhere laying sewage lines is a problem. InSweden composting toilets were firstintroduced more than 50 years ago. Though awide variety of models are being used, the‘Clivus’ Multrum model is one of the mostpopular ones (See diagram: the ClivusMultrum composting toilet).

THE CLIVUS MULTRUM COMPOSTINGTOILET

The Clivus Multrum is a single vault-composting toilet where urine, faeces and

organic household wastes are combined andprocessed together. The model is availableas a unit and consists of three maincomponents: a composting vault with aslanting floor; air conduits; and a storagespace at the lower end. Besides these, a tubeconnecting the toilet seat riser with thereceptacle and a sloping channel for thekitchen waste.

Faeces, urine and toilet paper along with allkinds of kitchen and organic householdwastes go into the multrum. The contentsslide down slowly along the multrum slopingfloor with the fresh deposits at the upper enddown to the storage part of the vault. Theheap decomposes, reducing to less than 10per cent of its original volume and graduallyforms humus. The humus produced hassimilar bacterial count as that of soil and isdirectly used as a fertiliser and soilconditioner. The humus produced in thisprocess is only taken out after five years forthe first time and later once a year. InSweden, this model is used in houses,weekend houses, institutions and as publictoilets. One problem is that since there is nodiversion of urine the slanting floor poses arisk of liquid accumulation at the lower end ofthe composting vault. To stop this a containerfor liquid storage below the composting vaulthas been provided in a newer version.

Urine separating toilets can be designed formulti- dwelling environment too. GebersHousing Project is a cooperative housingproject — a two-storied building with 32 flats— located in a suburb south of Stockholm.This project involves community participationand was started in 1998 with the primary aimof recycling all nutrients of the human wasteto agriculture.

The poor cannot afford sanitationsystems but pay for the cost of flushtoilets

The urine is flushed with a small amount ofwater and is carried by gravity to large tanks

under the building from where it istransported to a farm and stored in largereservoirs. There is a natural rise to a high phof urine and it is considered to be disinfectedafter six months of storage. Faeces on theother hand are handled dry and fall straightdown into individual bins under the house.The faeces is taken out after one year andcomposted collectively for later use inagriculture.

There are working examples in lessdeveloped countries too. China has a largeongoing ecosan programme. In the GuangxiZhuang Autonomous region in southeastChina, Yongning county has 1440 ecosantoilets in 45 villages. In the same region,another county, Beiliu, has 3,316 dry toilets.Most of these are in houses but some are inpublic use like schools. The faeces are driedin the toilets themselves and are collectedand used in three ways. They are put into abiogas digester and the gas made is usedprovide lighting and cooking facilities for thevillage. The leftover sludge is applied to fieldsas a soil conditioner along with the urine.Faecal sludge is also used for aquaculture.The circle is complete.

CHASING A DREAM

It is the poor who cannot afford sanitationsystems and are paying the cost of flushtoilets and sewerage. We pump our disease-laden effluents towards them. The medicalinterventions possible for the rich may be outof the reach of most poor people. Mostdeaths from waterborne diseases are notcaused not by the pathogens themselves, butbecause of dehydration, the victims do nothave enough clean water to drink.Malnutrition is also exacerbated by lack ofclean drinking water. Flush toilets hijacknatural resource like water that the poordepend to meet their daily needs.

Whether donor agencies or governmentsubsidy, there is a lot of money to be made insanitation and those in power will not easily

give up that power. So governments willcontinue to build flush toilets and keepchasing the impossible dream of sewerage.Sanitation engineers have no interest inchanging the technology paradigm. Waterpollution is not their problem in any case.

Flush with funds: building publictoilets in Delhi

There is no need to import expensivetechnological fixes. Ecological sanitationshows that there are new approaches, andthat these are based on traditionalunderstanding of the human- environmentrelationship. These are not really newtechnologies just a new way of looking atthings. Alternatives to the flush toilets andsewerage are needed and an understandingof basic environmental cycles shows us thepossibilities. Put back what you take out.

But most important need is a change inmindset. The flush and forget attitude is notworking. The faster we realise this, the better.

With inputs from Priyanka Chandola