Pit latrines in Nepal - the refugeedimensionby Jonathan Puddifoot

Design for camp living: the Bhutanese refugees' 'homes' and VIPD latrines.

In last April's issue of Waterlines, RichardMiddleton argued that, with careful planning and'community involvement, VIP latrines are safe,reliable, and affordable. Are they also thesolution to the sanitation problems endemic inan emergency situation? Jonathan Puddifoothas some encouraging answers.

THE INFLUX OF 86 000 Bhutaneserefugees into eastern Nepal during1992 and 1993 posed all the usualproblems for the agencies dealing withsuch a crisis. The United Nations HighCommission for Refugees (UNHCR)and its implementing partners -Lutheran World Service (LWS),Oxfam, SCF (Save the Children), andthe Red Cross - together with thelocal community and the Government,faced crowded camps, where uncon-trolled defecation polluted the ground-water, leading to high levels of diar-rhoeal infection, cholera, and typhoid.

Health impactWorking together with well-organizedrefugee camp committees, in onlythree years, LWS has managed to over-see the building of over 8000 venti-lated improved double-pit (VIDP)latrines, each costing less than $50.Each latrine is used by two neighbour-ing families, who have alreadyreceived the 'software' of personalhygiene messages, which are commu-nicated by a network of thousands ofvolunteer health workers in the camps.The software is as important as thelatrine itself: 87 per cent of the

refugees had never used a latrine, theironly option being open defecation.

The proper use of latrines has been

the major factor in the dramatic reduc-tion of diarrhoeal infection across allthe camps, and shows every sign ofcontinuing to do so, even after therefugee problem is resolved - 98 per

cent of the refugees have said that theywill try and build a VIDP latrine whenthey go home. As they have practicalexperience of building one, (theyassembled them in the camps) it seemslikely that a large number will do so.

But how much impact can buildinglatrines have? Assessing the impact ofsanitation on a community is notori-ously difficult. How do you isolate theimpact of sanitation from, for example,changes in diet or population? Whatabout other development efforts takingplace at the same time? A refugee

camp is very unusual: everyone eatsthe same food, everyone lives in thesame type of 'house'; it is as close to acontrolled community as you can get.

Figure I. Diarrhoea and latrine rates in Beldangi 2 Extension camp.

Careful monitoring'Month by month, SCF and LWS moni-tored the rates of reported diarrhoealinfection (typically, dysentery and giar-dia) and the number of latrines per 100people over a two and a half yearperiod - see Figure ] - showed ahigh correlation in most camps. Thehighest (83 per cent from Beldangi 2Extension camp) indicates the indis-pensable role latrines play in improv-ing public health.

From a peak average rate of 6.6 diar-rhoea cases per hundred betweenDecember 1992 and March 1993, afterthe latrines were constructed, this fig-ure dropped to 3.5 diarrhoea cases perhundred for the same period the fol-

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30 WATERLINES VOL. 14 NO.2 OCTOBER 1995

A customized VIPD

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Figure 3. Side elevation ofVIPDsuperstructure.

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Figure 4. Latrine design - section.

Note: Ring lengllr elf/w" /20 11/ lI'itll lI'eep-llO/e (a.\ Ihon-II) or 60<1/1.When 60cm. pit is deepened with till 111I1IIII'd .Ieetion be/oil' rin.ll •

Figure 2. Front elevation of VIPDsuperstructure.

B 1/dim nsioll ill cm• Vellt pipe, cap, j1j' cr ell and ~e"t-pipe

ba e .\upplied by mamifachlrer• 1/plastic part. welded will, !leatin plale.

except vellt cap ( elf-tapping -crew )

SuperstructureThe superstructure illustrated in Figures 2 and 3 provides:o Privacy for the user;o shade over the squat plat (to reduce flies); ando stops rainwater getting into the pit and flooding it.

A sandwich-panel roof, made of layers of flattened bamboo and plastic sheet-ing provides rainproofing. Bamboo poles with wattle and mud daub make up thewalls and the door of the superstructure. Fifty-seven metres of bamboo isneeded, at a cost of under $5. The abundance of cheap bamboo is a blessing!

SubstructureThe substructure (see Figure 4) provides two pits, each with a volume of around1m3, which is partially lined with 1.2m-wide concrete rings to add support to thepit sides, and made a base for the superstructure to stand on. The rings are cov-ered with concrete lids which also contain the ventpipe openings. These lidshave a joint and lifting rings cast onto them so that they can be removed and thepits cleaned out when necessary.

One problem with the siting of latrines in the Nepal camps was a high water-table in some areas: if a pit is dug a metre deep, the groundwater could becomecontaminated with E.Coli and other diarrhoeal bacteria. Other problems con-cerned the latrine-design life expectancy - how long are they supposed to last?Over-investment in latrines might be a waste of money if a solution is found tothe refugee problem, enabling them to leave the camps. Alternatively, underinvestment would lead to large, recurring maintenance costs.

The final design allowed for both these factors. A raised, twin-pit latrine keptthe pit base as far from groundwater as possible. The design life of the latrinewas split in two: a substructure with a ten-year life, costing $24; and a super-structure with a three-year life, costing $17. Naturally, as experience in con-struction was gained, the latrine specifications were modified, but the basicdesign remains unaltered.

What do the users think?In 1995, fieldworkers surveyed 186refugee families, most of whom hadbeen using their latrines for more thantwo years. The results showed almosttotal acceptance of the technology, with98 per cent of refugees having stoppedtheir traditional practice of open defe-cation. The essential personal hygienemessages have also sunk in - 80 percent of respondents said that they nowwashed their hands after defecating.

The original estimates allowed for anaverage of 12 people using each

lowing year, when latrine constructionwas nearly finished. The continuinguse of latrines maintains a decliningrate of infection across all camps.

Latrine kitsSo how do you go about building up to800 latrines per month - and manageto maintain high standards? LWSfound that the answer lay in a combina-tion of prefabricated latrine 'kits', andencouraging the refugees to assembletheir latrines themselves.

The tasks involved in building thelatrines were classed as 'skilled' and'unskilled'. The refugee family usingthe latrine performed all the unskilledtasks, with supervision and advicefrom the LWS workers.

Construction teams, many of themrefugees, did the skilled tasks such assetting ring moulds, hand-forming thesquat plate, and so on. The prefabri-cated parts (including the superstruc-ture kits) were then assembled on siteby the future users, and the latrine wascomplete.

Fabrication yards were set up in thecamps, where the kits were made up.One yard made superstructure kits,consisting of pre-cut poles and bracing,doors, and sandwich-panel roofs.Another yard made concrete-ring cov-ers. The rings themselves, the squatplate, and setting the chute pipe in thesquat plate, was done at the site of thelatrine.

Early construction efforts includedcasting the rings at the fabricationyards (special curing ponds were built)and then transporting them to thelatrine site. As each ring weighedaround 150kg and was very fragile,(the wall thickness of the rings wasonly 4cm), however, it soon becameclear that casting in situ was a muchbetter alternative, as it avoided bothbreakage during transport, and the needfor reinforcement in the concrete.

The ventpipe, fly-traps, vent cap, andthe chute pipe were ordered pre-cut tothe correct size from the supplier.

WATERLINES VOL. 14 NO.2 OCTOBER 1995 31

Relatively simple to construct - and local materials equal affordability.

The refugees have built their latrines - now they are ready to maintain them.

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Ripe for replicationThe experience in the camps in Nepalhas shown that it is possible to buildlarge numbers of VIP latrines in a shortspace of time; combined with educa-tion in appropriate health messages,this has a dramatic effect on the reduc-tion of diarrhoeal infections, as well aspreventing epidemics of cholera andtyphoid from breaking out.

The VIPD is a cheap and relativelysimple technology which can be usedin other, similar refugee situations, pro-vided that the materials and people areavailable. A level of refugee self-orga-nization makes it easier to both buildand maintain the latrines.

on a similar basis, with technical sup-port and training from LWS; UNHCRwill provide the necessary funds.

Jonathan Puddifoot is an agricultural engirleerwho has just completed an evaluation of thedouble-pit VIP latrine comtruction programmein the Bhutanese Project in Nepal's Jhl/paDistrict. He is now based at 22 Bower Street.Bedford MK40 3RE, UK. Tel:+44 234 272907.

system. The Bhutanese refugees ofJhapa are already managing the fooddistribution system, running schoolsand health posts, and allocating hous-ing with the help of UNHCR and otheragencies. The latrines will be managed

latrine. It was thought that a pit volumeof Im3 would be enough for one year'suse, when it would be sealed, and theother pit made operational. In fact, thepits take longer to fill; in some camps,the average fill-time is over 500 days.

Initially, there were concerns that thelarge amounts of decomposed materialto be disposed of would cause bothpublic health and logistical problems.But, over a year, the excreta in thesealed pits decomposes, leading to asignificant reduction in its volume,over 50 per cent in most cases.

The original volume of the pits wasaround Im3. Refugees dig a hole in theground next to the pit, and empty thedecomposed material into it. Peoplewere hopeful that the material could beused to make compost material for theForestry Department nurseries nearby;but the idea was dropped when itbecame clear that moving the largeamounts (about 2500m3 per year) ofdecomposing excreta cleanly throughthe camps would be too expensive.

Future maintenanceNow that the latrines have been built,and have proved to be a successfultechnology, the next challenge facingboth LWS and the refugees is how tomaintain them effectively. Not only dothe latrines need constant repairs andmaintenance, but the full pits need tobe emptied, the vent pipe needs to bemoved, and so on.

To get the best performance out ofthe latrines, a latrine-centred manage-ment system is required - the systemmust be designed to serve the individ-ual needs of each latrine. When thereare 8000 latrines, this means a decen-tralized system, a refugee self-managed

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32 WATERLINES VOL. ]4 NO.2 OCTOBER 1995