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1. D Cd d gin of a number of disdises liked td the lack of hygiene the quality and of water waste and insect and rodent vectors These diseases may not nec Put they are always responsible for a deterioration in the physical idividuals considered as a specialist s field public health engineering integral part of preventive measures on a par with vaccin Child care and so forth health engineering handbook includes dati sheets that may Rtoms as well as to the logistical and financial means available in 11 Tide emphasizes the three A s for all sanitation installation M reeptable a good knowledge of the population concerned is importa nically well adapted and Affordable moderate costs
2. heavier than air The Ventilation of chlonne stores should therefore be by means of vents at the bottom of the walls example residual chlorine The doses of 1 chlonne solution given here for the example of calculatin indication It may be that the chlorine demand of water to be treated in the The taste of chlorine water is proof of the presence of free residual chlorine it could be combined chlonne produces a corrosive and toxic gas chlonne demand are only an eld 1s very different from this 1 43 I Water in camps Technical briefs MONITORING CHLORINATION CHLORINE CONSUMED CHLORINE ADDED 1 DECOMPOSITION OF Haine M FREE COMBINED CHLORINE f CHLORINE IN WATER RESIDUAL EESORINE 2 TESTER POOLTESTER 1 44 Technical briefs T Water camps Monitoring chlorination Method The simplest and surest way of monitoring the effectiveness of chlorination of drinking water 18 to measure Free Residual Chlorine FRC The presence of FRC water after a contact time of 30 mins proves that enough chlorine has been added to oxidise all organic matter m the water plus leaumg an excess of chlorine available to deal with possible recontamination n the distribution system during handling etc The objectrue of chlorination see technical brief Chlorination 15 thus to add enough chlorine to leave between 0 2 and 0 5mg l of FRC after the contact time
3. A Grease trap B Grease trap with 90 elbow and tee in 3 compartiments Section Plan view 46 Technical briefs Sanitation Method A grease trap 15 used for separating solid materials oils and fats contained wastewater before its disposal in the ground If cils and fats are left the effluent they very quickly clog an infiltration system Two simple types of grease trap may be distinguished the choice of one or another type will be decided by the resources and skills available With an elbow at the inlet and a T at the outlet b With separating partitions Pnnciple In both cases the trap operates with three zones 1 Inlet zone which slows down and distnbutes the effluent in the trap 2 Middle zone where fatty material floats and accumulates at the surface and where heavier solids settle to the bottom 3 Outlet zone where grease free water flows out towards the underground dipersal system Construction Choose a place with easy access above the dispersal system soakaway pit infiltration trench Design the grease trap and draw a detailed plan see effective volume Excavate at the chosen place to dimensions greater than the trap to be Build the grease trap using locally available means and matenals e g cast concrete bricks or concrete blocks with an internal cement plaster Position the inlet and outlet pipes carefully to fachtate the flow and the operation of th
4. Sanitation Technical briefs EVAPOTRANSPIRATION AREA Section View from above partially in sectlon Technical briefs Il Sanitation This 15 useful where a soakaway pit or infiltration trench cannot be used because of impermeable soils e g clay or rock Evapotranspiration combines evaporalion of water from the sos and transpiration by vegetation S t ng at least 30m from groundwater points 5m from dwellings property boudar es trees and bushes Evapotransp ration is a complex phenomenon whuch vanes with latitude season and time of day An acceptable approximation is given by Evapotranspiration rate mm of water per day 0 8 x Evaporation rate The dimensions of an evapotranspiration area may be calculated on this basis n the absence of other data If the evaporation rate is not known it may be roughly measured using a square bas n of water placed on the ground Take measurements over several days and take an average Construction Prepare and mark out the area on the ground Dig the trench for the wastewater nlet pipe and the trenches of the evapotranspiration area Spread 5cm of sand on the bottom of the trenches Install the d persal drains 100mm perforated pipe on a bed of gravel Fill the trenches with a 50cm layer of sand and gravel m xture Cover everything with 10cm of soil Plant a quick growing local grass for high water consumption Build an embankment around the area to
5. Sedimenter or sand trap to separate sand soil etc hese structures become ideal vector breeding sites if they are not well ma he svstem d selon may be based on different te hniques Open channe bis ds the most simple and least costly technique but it entails maintenance bblems bloc Stagnant water damag to the sides etc bis technique should be used only for drainage of rainwater or of wastewater over distances the channel should be cement lined if possible and with enough slope to be self cleansing 9 II Sanitation Removal and treatment of wastewater Gravel drain The open channel may be improved lining t with plastic sheeting filling t with coarse gravel covering t with more plastic sheeting and then with earth The wastewater should never contam suspended material capable of block ng this type of drain which is impossible to unblock This technigue may be usedinan emergency for example at a d spensary or a laboratory Pipe drain This is the most effective way of removing wastewater but also the most costly Various types of pipe may be used PVC polythene cement fibrocement etc with a minimum diameter of 100mm The slope and the pipe diameter should be adequate for the flow and the pipes should be buried correctly 50 as not to be destroyed by the passage of heavy vehicles 20cm of compacted earth minimum Check regular
6. ootrest ti 5 optional Shuttenng timber 70mm about 5m Ventilation pipe hole only for VIPs Nails 8mm reinforcing steel bars Reinforcing steel 8mm 8m Template for form ng defecation hole Trough or board for modng concrete Trowel float Saw Hammer pincers Steel bar cutters Wire for jomung reinforcing bars Important If possible make a gentle slope towards the defecation hole this will ease clearung Don t forget the handles It 15 very difficult to move the slab without them If the slab is for a VIP latrine don t forget the hole for the ventilation pipe 150mm dia Take care over the curing 4 to 6 days in the shade t greatly affects the strength of the slab The template for the defecation hole should be tapered to ease 15 withdrawal from the concrete If embarking on a programme of latrine construction it is well worth the trouble to build a workshop for continuous production This workshop should have a water point storage for tools and a covered area for casting and curing slabs Sanitation Technical briefs POUR FLUSH LATRINE Technical briefs Sanitation Method Pour flush latrines are relatroely sample design but should only be considered where there 15 abundant water for flushing The latr ne is fitted with a pan and a water trap which stops odours from coming out and prevents flies from reaching the excreta Construction
7. 48 1 Water m camps 1 23 I Water in camps Technical br efs DIGGING WELL I 24 Technical briefs 1 Water in camps Digging a well Method The arm of this brief is not to Look at all the types of wells there are but to explain a technique which should be useful the absence of other technical skills Numerous techniques exist for finding water Good field observation particularly of the vegetation at the end of the dry season and above all the advice of local well diggers will help to decide where and how to dig Constructian Identify a suitable site vegetation etc Mark out a arcle about 1 2m diameter Dig to about 1m deep Erect a tripod with a pulley over the hole the legs of the tnpod must be firmly anchored Continue digging taking out all the soil as the work proceeds using a bucket and the tripod At regular ntervals as the hole deepens line the sides with wire mesh and plaster t with cement mortar When the water table is reached lower porous or perforated concrete rings using the tripod and continue to dig inside the rings these will descend into the water as digging proceeds The water which accumulates in the rings should be taken out as the work continues Place a layer of gravel between the sides of the well and the rings The capac ty of the well should be considered sufficient when there is always water remaining at the bottom of the well after drawing wat
8. Balanhidiasis rennes protozoa Helminthaasis caused by Ascaris and Ir churis s helminths It should be noted that these so called water borne diseases form part of the group of water washed diseases as well They may also be transmitted by any of the feeco oral routes dirty hands dirty food dirty water etc Besides these diseases water is also involved in the transmission of water based diseases in other words those diseases of which the causative agent passes part of its life cycle in an aquatic plant or an mal The different schistosomuases or bilharzias diseases caused by helminths worms which are usually contracted by contact with infested water washing clothes bathing etc but sometimes also via the oral route Dracunculias s Guinea worm transmitted only by drinking infested water 1 6 Water related health r sks I Water camps Lastly water may also transmit Leptospirosis bacterial disease which is contracted primarily by contact with water contam nated with the infected urine of various animals principally the rat but also by drinking such water All the infechous diseases transmitted by water with the exception of Guinea worm are linked to the pollution of water by the excreta of humans or other animals from the sick or from healthy carr ers Problems due to water based insect vectors One last category of water relat
9. Removal and treatment of wastewater Sanitation General principles For every place supplied with water there should be a removal system which prevents stagnant water and local pollution Treatment methods aim to fix the chemical and biological pollution by sedimentation filtration etc and or to destroy it by biological chemical or physical processes and then to dispose of the treated water by infiltration into the ground or into surface water river lake sea etc This field may become very technical and involves special expertise whuch is beyond our capabilities In practice the problems faced in the field are few and generally simple to solve for instance stagnant water around a water point well tap etc washing areas bathing cooking laundry etc laboratory and health centre wastes etc More rarely flushing toilets house or hospital sewers Removal A removal system should be able to remove wastewater so as to avoid stagnant water and to channel it to the d sposal or treatment site without contaminat ng the local environment The collection surface should be gently sloped 1 and cemented Before removal it may be necessary to pretreat the water to remove solid or dissolved matter whuch could hamper the removal and final treatment see technical briefs Grease trap to eliminate fatty material which mught block channels Screen to remove floating objects
10. The siting and construction steps are the same as for the simple pit latrine see the corresponding technical brief The simple pit latrine slab is replaced by one fitted with a pan and water trap In mady places such slabs be found ready made Otherwise it is possible to make a trap out of 75mm PVC pipe and fit it to an ordinary slab Connection If the pour flush latr ne 15 not connected to a sewer or on site treatment system eg septic tank the pit should be masonry lned as the heavy water flow would erode the wails of an unlined pit The lower half of the pit should be lined with open brickwork to let the water infiltrate into the soil It is possible to construct this type of latrine with emptyable twin pit if the infiltration rate 1s too low or if there is a risk of polluting groundwater points In this case the pit should be airtight see technical brief Twin ptt latrine To calculate the effective pit volume use a solids accumulation rate of 0 02m person year Preferably connect the pour flush latr ne to a septic tank see techrucal brief Septic tank Inputs Slab Pan Materials for superstructure Water trap Excavation tools shovels picks etc age pipe Slab with d water tr le slab Simple pit or alternating twin pit Slab with pan and water trap or simple 5 Open jomts m lower pit lung to allow ge fitted with 75mm PVC water trap of liquids Building matenals and tools for pi
11. i AN 19 din Technical briefs I Water camps Method The construction of a ferrocement water tank may be considered when planning to collect rainwater etc Its watertightness and strength are directly related to the quality of materials used and the care taken its construction A shape 1n ferrocement 15 created using a removable mould to which wire mesh i5 attatched and to which a cement coating 15 applied It 15 equally possible to build a framework of reinforcing steel whch avoids havmg to use a mould The steel is thus embedded in the cement coating and reinforces the structure Technique using wooden stakes for a tank of 1 5001 1 Drive stakes into the ground leaving at least 1 5m above ground level with centres spaced at 20cm to form a arcle 12m m diameter 2 Wind three thicknessess of wire mesh around the arcle of stakes Stretch and flatten the layers of mesh well against each other and fix them to the stakes and to each other with fine wire 3 Reinforce the structure by winding round it three turns of thick wire at the top in the muddle and at the bottom 4 Push a length of pipe with a valve attached through the mesh near the bottom for emptying and another one several centimetres higher with a tap for the outlet A third pipe for the overflow is fixed near the top of the tank 5 Apply 15mm first coat of cement plaster to the outside One person should be on the
12. pen Masse LET 274 94PU d MEDECINS SANS FRONTIERES A handbook for implementing health programmes in deprived environments particular in camps of displaced persons 1 edition 274 12531 PRAT SST eler SC EE REC ae Ya HE PUBLIC HEALTH ENGINEERING in emergency situation A handbook for implementing health programmes in deprived environments in particular in camps of displaced persons 1994 18 EDITION LIBRARY INTERNATIONAL REFERENCE CENTRE FOR COMMUNITY WATER SUPPLY AND SANITATION IRC Box 93190 2509 AD The Hague Tel 070 814911 ext 141 142 RN 11331 ra LO 24 g4 PU M decins Sans Fronti res Paris Octobre 1994 All rights reserved for all countries No reproduction translation and adaption may be done without the prior permission of the Copyright owner PUBLIC HEALTH ENGINEERING in emergency situation COORDINATION Gilles DELMAS MSF Michel COURVALLET MSF CONTRIBUTIONS in alphabetical order Yves Chartier MSF Guy Jacquier MSF Eric Laurent Solstice G rald Massis MSF St phane Quinton MSF Pierre de Rancourt MSF and Brigitte Renchon MSF MSF M decins Sans Fronti res FRENCH ENGLISH TRANSLATION JOHN ADAMS EDITING AND LAYOUT ANNIE ARBELOT Preface Public health engineering long considered a specialist field by medical organizations is not an end n itself It has a direct influence on sever
13. What is the level of the water table What seasonal variations are there What is the rainfall pattern What 15 the soil type 5 H Sanitation Excreta disposal What other physical characteristics of the site may influence the choice of system density of settlement proximity of water sources availability and type of building materials The system should be chosen with the answers to these questions in mind whulst remaining simple cheap and above all easy to install and maintain As a general rule individual family latrines prefered In most cases individual family latrines are socially more acceptable and pose fewer problems maintenance than collective systems If individual latrines are not possible because of population density centralised units may be built at the edge of a hving quarter or camp section where each family has access to its own latrine The area allowed for latrines should be big enough to dig new pits when the first ones are full Collective latrines usually pose maintenance problems When this system is adopted for a population or for a central service e g a hospital 1t is indispensable to appoint someone to be responsible and possibly to pay them to ensure good maintenance An excreta disposal programme Eight successive phases may be considered 1 Identify the problem site survey questions medical data etc 2 Initiate and organ se participation of the population consult loca
14. n the engine Check the general condition of the motorpump Fill up with fuel The filter of the diesel motorpump is an oil bath type fill t according to the instructions provided Fill the pump body with water The motorpumps in the kits are self primung so there is no need to fill the suchon pipe to encourage priming Start up the pump following the user s manual Record pumping times in the maintenance book to keep a count of pumping hours and plan the engine maintenance schedule Key Inputs 2 people to mstall the k t Float Strainer with non retum foot valve to exclude large impunties and keep the suction pipe full 1 operator for operation and maintenance of water when pumping stops Shovels and picks for preparing the site Water source river well etc Fuel petrol or diesel and motor oil Hehflex suction pipe 2 do not use ordinary fledble hose for the suction pipe Petrol or diesel motorpump Non retum valve protects against water hammer from backflow Heliflex delivery pipe 2 Reservoirs or water tankers for filling Hs suctionhead Hd delivery head Important The petrol motorpump kit is light and suitable for mobile use for limited pumping times e g on a pick up or a water tanker Max mum delivery 30m3 hour Total pumping head suction delivery 28m Fuel capacity 2 51 giving 3 hours running The motorpump is mounted on a frame and weighs 28kg The 4 stroke
15. 05litre person day may be taken 12 Collection and dispossal of refuse San tahon The percentage of putrescible matter may range from 20 to 70 These few figures simply present orders of magnitude and in practice the quantity and density or volume of refuse should be determined for each situation Its composition is only really important when disposal is by means of incineration or composting In general terms it may be assumed that the volume of refuse will be small when dealing with a population of rural origin and where the basic ration is in the form of dry foodstuffs as is often the case during the initial phases of an emergency operation Refuse containers The objectives are to gather the refuse to facilitate the collection to avoid dispersion by wind and animals Metal drums are generally used The bottoms should be pierced so that they do not retain liquids from decomposition and to avoid the drums being used for other purposes and they should be provided with covers and with handles for easy lifting In the first instance one drum per ten families may be provided placed at a reasonable distance from the dwellings Certain structures need particular storage systems either because of the specific nature of the refuse produced hospitals or because of the large volumes produced market slautghterhouse various workshops In these cases solid covered and easily cleaned b ns may be built In hea
16. 1 1mandays nn 11man days Unskilled labour 4 0 man days 4 0 man days PLASTER _ Perm 1 4 mix mem 173 mix 1 2mix Cement men 0 0025 00030m 2 0 0050 Sand 0017 001m _ rei 00108 Mason labour 0 14 u nenn 014 0 14 md Unskilled labour 2 022m d mu 022 M d ren un 0 22 m d Each coat of plaster 1 cm thick BRICK MASONRY 1 4 mortar A Bricks num en 75 Cement onanerer mmm enem 0 06302 Sand mome m o en een 02507 Mason labour namen nennen 14 m d Unskilled labour emer nn 2 Bd RUBBLE STONE MASONRY 1 4 mortar coo mascu mrenmen Perm Cement _ mu nenn 0 089m Sand nme en 035m3 Mason labour 14 md Unskilled labour mmm 32 DRESSED STONE MASONRY 1 4 mortar a Pern Cement mem 0 075108 Sand 30m Mason labour em Les 28m Unskilled labour nun ii ricerca merma 50md RA Ke m Portland cement cnc re 1 440 Brick masonry 2 120 Stone masonry see Lr een 2 450 Conarete nenne 2 409 Seasoned wood 650 Water cl nun 1 000 Dry stone masonry nn 2 000 IV 11 V Bibliography V Bibliography Bibliographie 3 4 10 11 12 13 ASSAR M Guide d assamissement en cas de catastrophe naturelle OMS Gen ve 1971 BURGEAP La construction de
17. Access for lorry Technical briefs I Water in camps 2 000 litres water storage kit Method This k t ts for the supply of water to a health structure dispensary small hospital feeding centre etc Once the base has been prepared a raised earth platform the bladder tank be operation m a few minutes InstallaHon Choose the site for installing the tank close to the centre to be served Important make sure that the s te is accessible at all times for filing the tank e g by lorry tanker Prepare a flat platform about 1 5m high so that the water may be distributed by gravity The higher the platform the better the distribution The surface of the platform should be cleared of all objects stones sticks etc which could puncture the tank If possible cover the surface with a layer of sand Important the area of the platform should be larger than that of the tank 3m x 1 7m Note also that this platform should be strong enough to support 390kg mv The platform may be made of compacted earth or oil drums filled with stones or earth with earth packed between them or a flat roof may be used etc Spread the groundsheet on the platform Lay the tank out on the groundsheet Tighten the outlet valve it is not completely screwed on by the manufacturer Attatch the pipe to the outlet Organise the distribution system in the health centre or right next to it using either the 1 4 turn valve supplie
18. Example of dimensions determination of a dispersal system The effluent of the septic tank of a health centre must be eliminated with infiltration trenches The effluent volume to infiltrate is 500 htres per day The infiltration rate of the soil is estimated at 10 litres m2 day The trenches will be 0 7m depth The effective infiltration surface is calculated the following way Volume of the effluent Ltre day 500 Infiltration rate litre m2 day 10 A trench is made of two vertical walls the total lenght of the trench is obtained by 50 2x trench s depth metre 2x07 ee Notice that only the vertical surfaces of the trench are taken into account when calculating the infiltration surface 50m Technical briefs Sanitation Soil permeability Technique The measurement of soil permeability by means of percolation tests allows 1 Judgement of the mfiltration capacity of a sod to be used for the dispersal of effluents 2 Determination using the results of the dimensions of a dispersal system Method Dig at least 3 test holes each one 150mm wide and 500mm deep on the proposed site Fill the holes with clean water and leave overnight or at least for several hours to bring the soil to a saturated state The next day fill the test holes with 300mm of water After 30 minutes and then 90 minutes measure the water levels in the holes Calculate the difference in level corresponding to this period
19. STANDARDIZED FORM WATER SUPPLY a Type de p b Litres person day c Condition of water EE dass 4 Surrounding condition e Distance between latr ne water point metres f Pumping yes no Maintenance g Reservoir yes no Maintenance h Tap stands yes no Mamtenance 1 Drainage yes no Maintenance 3 Wash ng area yes no Mamntenance k Chlorahon yes no If yes free residual chlorine 1 Bactenological analysis yes no If yes f cal col forms Turbidity yes no If yes turb d ty Family latnnes Bee a Is refuse problem n the camp b Is refuse collected c Are the shelters and surroundings well up kept d Are the public places dispensary market etc well up kept e Methods of refuse disposal family refuse p t collective refuse pit public rubish dump f Is the medical refuse ndnerated Remarks WASTE WATER RAIN WATER a Are there pools of stagnant water in the camp b Is rain water correctly drained Remarks VECTORS Are there many flies in the camp b Are there many mosquitoes in the camps c Does the population complain of rodents lice fleas Remarks E RSS CT 56 Technical briefs II Sanitation Sanitary surveillance Method The arm of sanitary surveillance is to perform a regular and continuous evaluation of the perfomance of a water supply and san
20. The measurement is most easily done using a Pooltester 1 R nse the Pooltester 3 hmes with the water to be tested 2 F ll the 3 compartments completely with water 3 Put 1 phenol red tablet in the left hand compartment measurement of pH 4 Put 1 DPD1 tablet n the night hand compartment measurement of Free Residual Chlorine 5 Replace the cover 6 Shake until the tablets are completely dissolved about 20 secs 7 Read the results in the ght comparing the colours in the outside compartments samples with those in the central compartment reference Key Inputs for 1 measurement Cover Central compartment PH compartment phenol red tablet 1 phenol red tablet FRC compartment DPD1 tablet 1 DPDI tablet DPD1 is marked n green on the packet PH readmg scale PH reference scale Water to be tested reading scale FRC reference scale 1 pooltester with cover 1 2 3 4 5 6 7 8 Important Never touch the tablets with the fingers th s could affect the results The printing DPD1 must be in GREEN on the packaging There are other DPD1 tablets with the printing in black They should not be used in thus pooltester Read the results within 60 seconds of the tablets dissolving to be sure of a reliable measurement Read the results in good light daylight Is best The pH need not be measured every ume It is used for determinung the amount of chlorine product to add to the wate
21. The packaging of certain powdered products needs special protection against rain craft paper bags Direct contact between the driver and the load should be avoided separate cab specially for powdered and granulated products STORAGE Insecticides should be stored under lock and key They should be out of reach of children animals and thieves The store should be separate and at a distance from food stores The building should be cool well ventilated and dry Ideally the store should not be deep so that drums of concentrated products may be handled without having to go right into the store Raise the containers off the ground if there is any risk of flood ng 11 17 Vector control Precautions for use and storage of insecticides Long term storage should be metal drums coated on the inside with a flexible varnish Use anti rust paint 1f there is any trace of oxidisation The drums should be stored on sides with the plugs of the drain holes towards the bottom and recovered with liquid in order to avoid the entry of air and humidity which would ox dise and denature the product Never store more insecticides than necessary as disposal of the excess requires very special techniques Empty containers There are several important precautions which must be taken when reusing metal containers Empty the conta ner well Rinse several times with a detergent solution Rinse a final time with a mixture of
22. accumulation rate 15 0 03m bed year 1 3 2 4m0 0 03 bed year x 20 beds For designing an underground infiltration system see technical brief Infiltration trench 14 year Technical briefs U San lation Method septic tank receives and treats wastewater before disposal underground dispersal by infiltration trenches The tank recewes all domestic wastewater sewage and sullage and 15 surtable for wastewater from schools hospitals etc Operating Pnnciples A septic tank is a container usually rectangular in shape built just underground in which wastewater is retained for 1 to 3 days During this period solid material settles and is decomposed by bacteriological action Although this biodegradation 1s reasonably active the accumulation of solids means that the tank needs emptying at regular intervals generally every 1 to 5 years The effluent from a septic tank needs secondary treatment before final disposal in the environment It is punfed and disposed of by underground dispersal via infiltration trenches positioned after the septic tank see technical bnef Infiltration trench Design prinaples In order to reduce the concentration of suspended matenal the effluent the tank has a partition separating it into 2 compartments the first having double the volume of the second The depth of the liquid zone is 1 to 2m The length of the tank is usually 2 to 3 times its width The volume of the tank is
23. activo Adsorbente Letrina sobre dos fosas Banqueta Chloro act vo Capa fre tica Autoclave Bactenas Anal s s bacteriol gaco IV Glossary Definition Incorporation of one substance by another e g of a gas by of a liquid by the soil Rate at which decomposed faecal matter builds up in latr ne pit expressed m3 per person per year and used for the calculation of effective pit volume Specially prepared powdered or granulated carbon used in final treatment of drinking water by absorption particularly for the removal of dissolved organ c pollutants which impart taste and odours to water Solid particle e g activated carbon of very large surface with the property of fixing dissolved solids and colloids in water Latnine with two pits used alternately Concrete surface surrounding the head of a well for protection and drainage Pure chlorine content of a chlorine generating product expressed as a percentage or 1n chlorometnc degrees e g gt 70 for calcium hypochlorite Saturated permeable underground rock formation Equipment for stenilization by saturated water vapour humid heat during 20 mins at 135 C 2 bars or 30 mins at 121 C 1 bar Microscopic unicellular organisms certain of which are disease causing agents Identificabon of bacteria of the coliform group and or other micro organisms nd cat ng contamination of water by f cal ma
24. and by or more representatives of the population and anyone else who 15 influential and who has a good knowledge of the place and the people The indicators to be monitored are most commonly chosen according to specific objectives and standards set by the programme These indicators may be water quantity the number of people water point litres person day number of containers family water quality free chlorine residual bacteriological quality turbidity taste and odour disposal of excreta and refuse number of people Jatnne refuse pits family or section etc Key Inputs 1 sanitary surveillance form adapted to the particular atuation Example of a sanitary surveillance form 1 bucket 10 or 201 and a watch for measunng water flow 1 Pooltester if chlorination is done to measure free chlorine residual see brief Monitoring chlorination 1 portable bacteriological analysis kit if the programme demands see brief Water sampimg Important The analysis of epidemiological data collected in curative health structures morbidity due to charrhoeal dermatological and opthalm c diseases and diseases transmutted by insect vectors is complementary to the sanitary surveillance carned out on the ground It allows a relationship to be established between the health status of the population and its general living conditions and hygiene It also allows better targetting of action to take and of the
25. and let air circulate inside Do not fold up the tank until the inside is completely dry 2 3 days at least repair the tank use the repair k t supplied and follow the instructions carefully 1 49 I Water in camps Technical briefs 15 000L WATER STORAGE KIT BED Earth platform Clean the surface of the platform Lay out the ground Street Lay out the tank Connect outlets Arrange the drainage and lorry access 1 50 Technical briefs I Water m camps 15 000litres water storage kit Method This lat 15 designed to supply water a camp Once the base has been prepared a raised earth platform the bladder tank be operational in a few minutes Installation Choose the site for installing the tank ensuring that it is accessible at all times for filling the tank eg by lorry tanker Prepare flat platform about 1 5m high so that the water may be distributed by gravity The higher the platform the better the distribution The surface of the platform should be cleared of all objects stones sticks etc which could puncture the tank If possible cover the surface with a layer of sand Important the area of the platform should be larger than that of the tank 64m x 32m Note also that this platform should be strong enough to support 730kg m The platform may be made of compacted earth or drums filled with stones or earth with earth packed between them or a
26. are Zinc phosphate 1 to 5 fluorocetamide 2 sodium fluoroacetate 0 25 certain anticoagulants Multiple dose poisons These are anticoagulants with a cumulative effect used at low doses which have two advantages slowness of their effect allows the animal to absorb lethal dose before the first effects are felt Their mode of achon makes them less dangerous to man and other domestic animals and there 15 an effective antidote Products in use See the table on the following page The bait 15 bought ready to use or made with broken cereal grains which are soaked over night to moisten them to make a thick paste Sugar may be added 5 to make it more attractive as it is important to persuade the animal away from its usua food and get it to stick to this new diet The poison 15 then mixed in and the bait 15 laid on the rodents trails in piles of 25g or 200g or more rats These baits should be out of reach of other animals They can be laid in particular ways e g a slightly open plastic bag a short piece of pipe a small wooden box etc 14 The principal vectors biology and control methods HI Vector control Effects should be seen in 3 weeks for the brown rat 4 to 5 weeks for the black rat and the mouse The baits are always renewed and left in excess The dead bodies should be disposed of guickiy and well p ck them up twice per day and put them n a
27. be water from less than 3 metres deep should be treated like surface water Subject to seasonal variation in quantity RAINWATER In non industrialised regions rainwater is relatively pure and may be consumed without treatment as long as it is collected with certain precautions ie on a clean surface tin roof tent plastic sheeting and the first flow of water is rejected Although rainwater rarely provides a regular supply it may sometimes be a useful temporary or complementary supply it may be a good alternative to heavily polluted surface water during the rainy season Warning The exclusive consumption of rainwater without a complementary intake of essential minerals such as iodine causes problems in the long term Rainwater dissolves the metal in which it 1s stored Do not use containers or pipes made of copper zinc or lead clay cement or plastic containers are suitable 1 9 Water in camps Water supply practice there is rarely a choice between these different sources of water particularly in emergency situations When settiement begins surface water the most polluted or the most easily polluted is often the only supply available It is therefore mperative to concentrate on the problem of water as top priority Sometimes at first supply by water tanker is the only solution Other solutions should quickly be planned drilling digging wells moving the camp etc specialist advice
28. briefs Vector control Technical briefs Classification of insecticides 111 22 Chemical methods for insect control 11 23 Formulations 24 Propoxur 1 26 Permethrin 27 Deltamethnn 28 Malathion 11 29 Pyrimiphos methyl 30 Temephos 31 Repellents 32 Impregnation of mosquito nets I 33 HI Vector control Technical briefs Classification of insecticides classification enables the grouping of chemically related compounds to deduce their toxicity and precautions for use MINERAL COMPOUNDS Mineral oils spreading on the water surface asphyxiates and poisons larvae which are there mosquitoes etc ORGANOCHLORINE COMPOUNDS NEUROTROPIC POISON DDT Dichloro diphenyl trichloroethane a compound of low toxicity to vertebrates Effective against mosquitoes ectoparasites lice fleas etc Contact insecticide Large problems of resistance and bio accumulation not very biodegradable Methoxychlorine same as for DDT Partially biodegradable HCH Hexachloroocyclohexane Lindane Gamurexane more toxic less persistant than DDT but less resistance and more biodegradable Chlordane used only for controlling cockroaches and grasshoppers Dieldnn very toxic problems of resistance To be avoided ORGANOPHOSPHOROUS COMPOUNDS ACETYLCHOLINESTERASE INHIBITOR Malathion low toxicity used agaist ectoparasites and mosquitoes Fenitrothion low toxicity used agai
29. calculated on the basis of a 3 day retention time of the quanhty of water entering the tank each day see example on opposite page The effective depth of water should not be less than Im Frequency of emptying The tank should be emptied when it 15 1 3 full of solids The frequency of emptying is given by 1 3 volume of tank m solids accumulation m pers year x number of pers The solids accumulation rate depends on temperature A figure of 0 03m pers year is considered a reasonable average After emptying it is advisable to fill the tank with clean water years Key Floating material ous fats Clanfied liquid Plans Settled solids Shovels picks etc Inlet tee Builder s tools Outlet tee Partition to retain solids and floating material Sand for sub base Access holes with covers Shuttering timber Ventilation Concrete quantity calculated accord ng to tank 20 of effective depth volume concrete blocks or prefabricated b 40 of effective depth elements 3 ac Pipes and inlet and outlet tees m r mum dia least 75cm 100mm f effective depth of water murumum Im Ventilation pipe 1 2 3 4 5 6 7 8 Important A septic tank may be built in situ n concrete or concrete blocks or alternatively with prefabricated panels n concrete fibre or plastic Whatever the construction method the tank must be water hght and strong enough to resist soil and po
30. clean and healthy Incineration Inan rahon Incmeraci n Action of reducing refuse to ashes naneration of medical refuse Infiltration Tranch e Zanja de Structure for disposing of wastewater trench d infiltration absorci n by underground drainage using IV 6 trenches and drains IV Glossary English French Spanish Definition Irrigated garden Jardin irrigu Jard n nrigado Vegetable garden watered with wastewater recovered from water points an alternative technique to infiltration systems L Leachate Liquide de L quido residual Liquid resulting from the fermentation de fermentaci n decomposition of organic matter refuse tip Lysol Lysol Lysol Solution of cresol and soap powerful disinfectant used for floors and other surfaces M Medical waste D chets m dicaux Desechos m dicos Refuse from the activities of a health centre Medical waste 15 potentially contaminated see Contamination Micro organisms Micro organismes Micro organismos Microscopic animal or vegetable orgarusms Motorpump Motopompe Motobomba Pump powered by an electric motor or combustion engine N Non return valve Clapet anb retour V lvula de Valve allowing water to flow in one retenci n direction only installed at the start of a delivery pipe from a motorpump to stop backflow when pumpmg stops Oxid ze Oxyder Oxidar To transform into the oxidised state by combination with oxygen Organic matter Mat
31. collection and d posal Organise regular clearung and disinfection of the dustbins Hammer the cut edges to avoid injuries Technical briefs Sanitation TEMPORARY INCINERATOR P 9 3 5 u 11 36 Technical briefs Sanitation Temporary incinerator Method This incinerator serves temporary purpose in a dispensary or health centre If the health structure becomes permanent it should be replaced by a permanent incinerator Cut the top cleanly off a 2001 metal drum around 2 3 of its perimeter see fig 1 Cut a hole the diameter of the chimney in the remaining part of the cover Perforate a metal plate length internal height of drum width diameter of drum at the place the cover was cut all over its surface with holes about 1 2cm diameter Shde t into the drum and fix it so as to divide the inside into two chambers of unequal volume Fix the cut part of the cover to the top edge of the plate with hinges Attatch a handle so that this cover may be opened and closed Cut some rigid metal grating or make some with the same cross section as the large chamber of the drum n front of the metal plate and t horizontally about 20cm from the bottom of the drum Cut out panel 40 x 40cm at the bottom of the drum and remount t as a door using hinges Fit a dumney about 2m high on the hole made in the fixed part of the cover Operation Fill with
32. flat roof may be used etc Spread the groundsheet on the platform Lay the tank ont on the groundsheet Tighten the outlet valves they are not completely screwed by the manufacturer Alfatch one of the three lengths of pipe to one of the outlets fit the tee and the two other lengths of pipe to the other outlet Organise the distribution points using either the 1 4 turn valves supphed with the k t or distribution tapstands there are 2 stands each with 6 taps in the MSF Distribution tapstand kit Install a drainage system around the platform and around the distribution point s to avoid rapid deterioration of the site Key Inputs Reservorr bladder tank Filling opening with ca OI Dd c Unpack the shovels and picks first of all to 2 persons per k t for installation Gullemin syst prepare the platform If mechan cal equipment Bao e g a bulldozer can be used it is much quicker 6m of 2 reinforced hoses DN50 3 suitable and easier for use with drinking water Means of filling motorpump lorry tanker etc Serflex collars for gnp and watertightness e ti in MSF tapstand kits with 6 Spanner for loosening and tightening the Di tribgHon points eg hi hose connections taps 1 4 turn distribution valves 3 2 tee connection DN5O 2 shovels 2 picks Handles for shovels and picks Roll of rope Important Site the distri
33. health centres etc They may equally well be used for disposing of water from septic tanks Construction 1 Choose a site at least 30m from groundwater points 6m from dwellings and 3m from trees or hedges and 3m from possible property boundaries 2 Determine the dimensions of the trench or trenches according to the permeab l ty of the soil and the quantity of wastewater to be infiltrated see technical brief Sod permeability 3Dig the trench for the incomung pipe 300mm wide 1 slope 4 Lay the pipe 100mm and cover with earth 5Dig the infiltration trench to the required dimensions with a slope of 0 5 to 1 6 Rake the sides and bottom of the trench Do not walk in the trench after this step 7 Fill the trench with gravel up to the level of the inlet pipe minimum thickness 100 150mm B Extend the inlet pipe about 0 5m into the infiltration trench 9 Lay the drain perforated pipe or pipe sections with loose joints Plug the far end 10 Fill the infiltration trench with gravel to a thickness of 50mm over the drain 11 Cover the gravel with straw or a plastic sheet 12 Fill the trench to the top with earth and compact it lightly 13 After one or two weeks plant grass on the top to limit erosion Permeable soil 1 tape measure Gravel Shovels picks Incoming channel 1 wheelbarrow Drain perforated pipe 1 pipe 100mm dia in cement or day Straw or plastic sheet 1 perforated pipe or pipe sections w th Eart
34. health messages to spread The information gathered dunng a sanitary survey should be interpreted and communicated to everybody involved in the programme without forgetting the local staff who work directly with the population concerned It is important to maintain the frequency of surveillance in order to sustain interest and to follow the evolution and impact of sanitation and water supply activities over 1 57 Sanitation Technical briefs 1 58 Technical briefs Sanitation Inputs Important 59 Vector control This chapter 1 an introduction to vector control It presents some methods of chemical control of the principle disease vectors It should always be born mind that a large scale control programme necessarily demands specialist skills A Introduction B The principal vectors biology and control methods C Precautions for use and storage of insecticides D Spraying material E Technucal briefs Introduction nn _ HI Vector control Introduction Since the introduction of DDT forty years ago numerous chemical products have been invented for the destruction of disease vectors and agricultural insect pests Two major problems have appeared Many insects vectors have developed a resistance to these products Their human tox city has at times caused serious public health problems In the context of the work of M decins Sans Fronti res we are confronted by
35. if there is resistance Prepare an aqueous solution of 4 active product add a gentle detergent if possible e g fabric detergent or shampoo to aid the penetration into ticks and apply about 15ml to the head of each person Leave to act for 24 hours before r nsing Do not use on children of less than three years Deltamethrin may also be used as a solution of 0 03 active product 2 5ml of concentrated solution litre or one sachet of 33g litre of water or a 0 05 solution of permethrin This treatment should be avoided 1f at all possible The principal vectors biology and control methods Vector control Flies General points This order 15 composed of a wide range of species which differ in their ecology their behavior and their medical importance The domestic fly has a life cycle of 10 to 30 days depending on temperature The larvae develop in mammal and bird excreta in waste waters and in decomposing organic matter medical and domestic refuse The adult which lives for 2 to 8 weeks has a radius of activity of about three kilometers It feeds on moist or liquid substances rich in sugars and proteins This species is closely linked to the human environment and frequently moves between contamunated areas excreta medical wastes etc food and drink thus playing a disease carrying role Other species are of particular medical importance due to their specific biology those attracted by lacrymal or nasal secre
36. inside to retain the mortar with a float as it 15 applied Leave it to harden for 12 to 24 hours keeping it damp 6 Pull out the stakes and cut off the wires which stick out 7 Apply a coat of cement plaster to the inside so as to cover the mesh completely Leave it to harden for 12 to 24 hours 8 Apply finishing coat to the inside and the outside and smooth well 9 Cover the bottom of the tank with wire mesh and curve it up at the corners where the walls meet the bottom Plaster the base forming a slope towards the emptying pipe Inputs 20 sharpened wooden stakes 50 x 50 x 1 750mm Wooden stakes 25m of fine wire mesh 12mm mesh 1 5mm Wire mesh wire Overflow pipe 2 3 bags of cement Tap 500kg of building sand 3 x 30cm lengths of metal pipe one fitted with Emptying pipe tap and one with a valve Galvanised steel wire 2 2 5mm dia 1 roll of fine wire 0 5mm Exterior coat of cement mortar 1 roll of thick wire 2mm Interior coat of cement mortar Mason s tools 2 people for 3 days 1 sledgehammer Important Preparation of cement mortar 1 part cement to 2 or 3 parts clean sieved sand Final thickness of tank walls 30 to 40mm A metal cross piece is welded on the pipes to anchor them the mesh before plastenng To make cover on the tank t is possible to extend the mesh with 1ts shuttenng or reinforc ng steel framework An inspection hole wit
37. necessary The bottoms and tops of the rings are stepped so that they fit together well The groove may be formed using a template or a plastic tubing against the internal face at the bottom of the mould and against the external face at the top when the mould s almost full of concrete The mould sections are removed about 24 hours after casting The rings should be cured n the shade for at least 1 week during whuch they should be kept damp wetted jute sacking or plastic sheeting For perforated mngs the moulds are made with holes every 13cm Greased pegs are inserted when the Concrete 15 cast they are withdrawn before the concrete sets completely After each use the mould sections should be scraped and brushed and the contact surfaces coated with used engine oil or diesel to prevent concrete sticking to them Key Inputs External mould diameter 1 15m 2 workers Cement sand and gravel about 0 25m3 of Internal mould diameter Im concrete per nng Concrete ring 1 nng mould Bolts 2 shovels 2 buckets 2 trowels 1 brush Used engine 1 spanner 1 lump hammer Plashe sheeting or jute sacking Wooden or metal pegs for perforated rings Reinforcing angle steel Important Concrete mix for ordinary or perforated ring is 1 2 4 cement sand gravel Compact the concrete well during casting to drive out air bubbles Concrete mix for porous rings is 1 1 4cement sand gravel The conc
38. parts and maintenance skills The pumping schedule a few hours per day or 24 hours per day Calculation and comparison of the costs of different options Note The suction ability of a surface pump is limited to 7m head at sea level whatever its power It diminishes as the altitude increases see table opposite On the other hand its discharge capacity s directly related to its power The discharge of a pump can be regulated by means of a valve at the discharge outlet 1 37 I Water in camps Technical briefs CERAMIC CANDLE FILTERS SIPHON FILTER type Ecla r GRAVITY FILTER Type Esser 10 or 201 or4 candles PUMP FILTER FILTE Type Katadyn Type Carbatom Technical briefs I Water an camps Ceramic candle filters Method Ceramic candle filters can remove practically all bacteria some viruses and all suspended material from water Important Hus technique 15 not effective for dissolved substances salts chemical pollutants etc Water 15 passed through microporous ceramic walls with pore diameter of about 0 454 Siphon filter Place the water to be filtered in a container immerse the candle place another container underneath and let the filtered water siphon through drop by drop the siphon is pnmed automatically Gravity filter The same as above but one container stacks on top of the other This method produces a greater flow than the siphon as it uses sev
39. poisoning For engine driven sprayers protect the insecticide feed pipe from the exhaust pipe The preparation stage dilution filling the tank 16 the most dangerous as concentrated products are handled During preparation and treatment the following rules should be respected and enforced Do not smoke drink or eat Do not keep cigarettes on you Do not put anything to your mouth to unscrew blow unblock etc Wear protective equipment corresponding to the toxicity of the product being used Powder dust mask and gloves Liquid canvas overalls wide brimmed hat boots and gloves resistant to hydrocarbons side protection glasses and mask For the mask the cartridge should correspond to the product being used and should be changed regularly every 60 hours in the open ar Check that it is airtight before starting work take care of beards hair etc Make sure that these safety precautions are feasible heat etc Do not spray if it is windy Establish a rotation of the team to avoid too long exposure for each individual Empty and clean the equipment at the place of treatment Do not throw remaining products ditches ponds water courses or any place which may involve pollution of the aquatic environment Ensure that the staff are well trained in taking the above measures Ensure that the medical services have been warned and that they have the means to take the
40. population displaced people need access to good quality water in sufficient quantity This need is that much greater in camps where the population concentration increases the risks of pollution and of epidemics of water borne diseases Quantity The notion of sufficient quantity is very subjective and depends strongly on the climate and on the habits of the population Nevertheless it may be assumed that ten htres per person per day is a minimum need while aiming to reach the following targets as soon as possible UNHCR 1982 For domestic consumption 15 20 litres per person per day drinking cooking hygiene For collective feeding centres 20 30 litres per person per day For hospitals 40 60 litres per person per day In case of severe shortage daily ration of 4 to 5 litres may suffice very provisionally Unless there is a shortage it is better not to put any limit on consumption as the health status of the population is influenced by the quantity of water used Itis not enough to supply 10 15 litres of water per person per day to a camp people should actually be able to use this quantity Therefore water should be reasonably accessible in terms of distance and of waiting time at the water point and the means to transport and store it should be available if the supply is via taps allow at least one tap per 200 250 people and arrange these taps in groups of 6 or 8 maximum It is important to ensure that th
41. protect t from run off Key Inputs 2 wheelbarrows 4 shovels 2 picks Dra ns 10mm perforated pipe E PE e 100mm PVC soil Tee for inlet pipe to drains Quick growing vegetation Sand and gravel Run off protection embankment Sol Quick growmg grass sown or planted out Impermeable soil Sand and gravel Important The evapotranspiration area is most suitable for hot arid or semi arid climates Choose a short rooted grass which needs a lot of water for growth Cut the grass regularly Use a grease trap see corresponding brief when the wastewater onginates from a k tchen or washung area Design calculation example A dispensary n a hot dry tropical zone generates 3001 of wastewater per day The rocky soil will not allow underground dispersal The evapotransp ration rate 15 10mm day Evapotranspiration rate 10 x 0 8 8mm or 0 008m of water day volume of wastewater m day 03m d LLL 37 52 evapotranspiration rate mm day 0 008m d 1 51 U Sanitation Technical briefs STERELISATION BY AUTOCLAVE Matera be serchzed Duration n 8 Atm Bar or Kg cm Instruments plastic or glass synnges rubber 250 Bandages compresses operative hnen and clothes Overpressure in comparison with the atmospheric pressure Add 5 munutes for every 1 000 metres of altitude 52 Technical briefs Sanitation There are many types of autoclave on the market They work the
42. refuse frequently during combustion to make the ashes fall and to expose all the refuse to the flames Never put explosive objects g aerosol cans n the incinerator or materials which give off toxic fumes on combustion certain medianes for example Always seek advice before m case of doubt Situate the incinerator where the smoke will not bother people and place it under a shelter if possible to avoid corrosion being worsened by rain The door 6 may be adjusted to regulate the draught However 1f the draught is enough incineration with the door closed is the most economical on firewood If it is used frequently such an incinerator will not last more than a few months less than a year because of corrosion due to the great heat generated 1 37 Sanitation Technical briefs PERMANENT INCINERATOR All dimentlons in cm Plan view Technical briefs IL Sanitation Permanent incinerator Method This nc nerator 15 useful for a dispensary a hospital or a health centre for disposing of refuse generated by medical act ml es Domestic refuse should not be incinerated but buried see technical brief Controlled t p 1Draw a detailed plan of the structure 2 Buuld brick foundations 100 x 70 x 20cm overall dimensions 3 Shutter and cast the base slab fire chamber slab upper slab and ch mney top slab 4 Lay the base slab on the foundations 5 Build the refractory brick walls up to the he
43. responsible for the transmission of dengue yellow fevers and other arboviruses mosquitoes of the Culex genus which breed in stagnant water heavily loaded with organic matter and which are liable to transmit microfilariases rodents which are directly or indirectly responsible for the transmission of various diseases such as plague leptospirosis and salmonella and whose presence attracts snakes In addition to these health risks poor management of the collection and disposal of refuse may involve the pollution of surface water or groundwater and increase the risk of fire Lastly the aesthetic aspects sight and smell are far from negligible These nsks and nuisances are all the more serious at high population densities Certain types of refuse from medical activities represent a particular msk and so need special attention Type and quantity of refuse The type and quantity of refuse produced by a community are extremely variable The main factors affecting the composition of refuse geographic region sociocultural cultural and material levels which may produce great variations even within the same community seasonal variations the importance and diversity of refuse generating activities workshops dispensaries etc packaging of food ration The density of refuse is in the order of 100 to 200 kg person day and the volume varies between 05 and 10 1 person day an average value of
44. rod Fence Stakes and fencing material Excavated 2 people for 1 day depending on size of pit Water table 1 miner s bar L 2 3 4 5 6 7 8 Dwellings Refuse p t Latrine Well Important Only throw household refuse the pit Do not throw in medical waste potentally contaminated before ncineration Ifthe soil is too unstable it may be useful to support the walls with uncemented bricks It is not efficient it is expensive to bum household refuse Thus technique described technical briefs Temporary incinerator and Permanent incinerator should be reserved for medical wastes It is essential that refuse 15 covered with earth or ashes immediately after disposal to avoid attracting flies and rodents and to accelerate decomposition In certain cases hospital feeding centre when the quantities of non medical waste to be disposed of need a very deep pit it may be covered by a slab for safety with a covered opening The cover should be heavy and fitted tightly to the opening to prevent the entry of flies Make sure that the cover 15 replaced after each use 1 31 Sanitation Technical CONTROLLED TIP 4 2 1200 people week 5 Distance from camp gt 1 km Direction of run off french In longditudival section 1 32 Technical briefs H Sanitation Controlled tip Method This technique 15 used to eliminate a community s waste Its feasibility 15 e
45. same principle water vapour under pressure l ke pressure cooker but are operated in different ways The mixed energy autoclave described here Daguerre type 1s particularly suitable for emergency situations as it can be heated by electricity kerosene stove gas or charcoal Procedure for use Put water in the autoclave 8 litres if heating by kerosene gas or charcoal 16 litres f heating by electricity Load the boxes with covers open into the autoclave Close the autoclave bghtening diametrically opposite clamps Choose the pressure required by moving the weights st notch 1 bar 121 C 2nd notch 2 bars 134 C Close the Yellow Red and Blue valves leaving the Green bleed valve open Put on full heat As soon as a continuous jet of steam comes out of the Green valve close it until the pressure reaches 1 bar then open it and let the pressure fall to 0 2 bar Repeat this operation at least once in order to eliminate all avr pockets Let the pressure rise until the desired pressure temperature 15 reached 121 C or 134 C As soon as that pressure 15 reached the regulating valve releases steam Count the sterilizati n time from this moment and start the umer Reduce the heat position 1 or 2 on the electric heater or reduce the kerosene or gas flame to keep just a light jet of steam coming out When the sterilization t me 1s finished cut the heat and open the Yellow valve Be careful of the jet ofborling steam use a flexibl
46. superstructure 6 Fix the ventilation pipe at the back of the latrine It may be round or square made of PVC metal bricks reeds with earth plaster etc It should be vertical with an internal diameter of about 150mm A screen of mosquito netting 15 fixed at the top of the pipe to prevent the entry and ext of flies Fit a roof to the superstructure with the slope carrying rainwater towards the back Important the ventilation pipe should extend 50cm above the highest part of the roof 7 Dig a drainage channel around the latnne to prevent erosion of the pit walls Inputs Effective pit volume Defecation or squatting hole Shovel pick miner s bar Special VIP slab Mosquito netting preferably nylon Pipe of PVC or building matenal Ventilation pipe internal diameter 150mm Maternal for superstructure and door Mosquito netting 1 2 3 4 5 6 7 8 9 10 Important The slab and surroundings should be deaned every day If possible provide l ght ng for ght use Never put disinfectants chlorine products lysol etc in the pit this only serves to inhibit the natural decomposition of material The only situation 1n which it Is recommended to pour disinfectants in latrine is during a cholera epidemic On the other hand t is recommended that fire ashes are put into the pit after each use This gives a perceptible reduction of odours and accelerates decomposition When the pit 15 n
47. will usually be needed Sometimes a piped supply from an urban area may be possible Priorities Designate defecation areas far away from water points What are the priorities in terms of water supply when dealing with a concentrated population Before anything else Find out where and how the people go to collect water and where they defecate Then Distribute water containers if necessary very important Take specific steps to protect water points Determine the amount of water available If necessary set up a water rationing system Finally If necessary increase the output of the w ter points or look for additional sources of supply Create a reserve water stock Improve measures to protect water points If possible set up a system whereby water is pumped into reservoirs before being distributed Check water quality if necessary Possibly install a treatment system WATER POINT PROTECTION MEASURES All the protection measures aim at preventing the introduction of f cal germs into the water either directly or indirectly by run off or dirty soil falling into the water etc Protection of water courses 1 10 Organize the use of the water course according to environmental health considerations The point used for collecting water should be upstream of all other uses Note surface water is always difficult to protect th
48. 1 solution per leave it for 12 hours and empty it through the plug holes Never chlorinate after this it would destroy the biological layer Cover the drums to prevent the growth of algae It 15 vital that the Schmutzdecke at the surface of the sand is always covered with water agam make sure that the outlet pipe nses above the level of the Schmutzdecke Flow setting close the outlet valve Open the inlet valve not too much to avoid puttmg the prefilter sand into suspension when the filter is open the outlet valve so as to have an outflow of about Il min The Schmutzdecke is only effechve after about 2 weeks so for the first 2 weeks of service the water is not safe Such filter can treat 1 000 to 1 400 1 24h If the needs are greater several filters may be built in parallel this also avoids having to cut the supply during maintenance Maintenance when the yield drops significantly cut the inflow and undo the plugs of the two drums Let the water empty completely from the prefilter Let the water level n the filter fall to 15 20cm below the filter surface rake the top 1 2cm of sand from the Schmutzdecke Replace the plugs and put back into service After this has been done several t mes remove about 10cm of sand and put it to one side Place a layer of clean sand and then replace the 10cm to bring the total thickness of fine sand back to 70cm If the water 15 not very turbid 30 NTU the prefilte
49. 20 minutes After 20 m ns boiling take out of the water and let it cool protecting the opening with flamed aluminium foil or a sterilized compress Use as soon as possible For the bacteriological analysis of water that has been chlorinated add 0 15ml of 1 sodium thuosulphate solution per 100ml of sample to each bottle before sterilizing in order to neutralize the chlor ne which would otherwise affect the results Key Inputs 1 8 water sampling from a tap for bacteriological Chemical analysis Glass or plastic bottles 1 or 1 51 2 per sample Marker pen for labelling Thermometer Bacteriological 2 sterile 100m bottles 1 Clean the tap alcohol or soap 2 Let the tap run fully for about 30 seconds 3 Flame it with a pad soaked m alcohol 4 Letit run fully again for 30 seconds 5 Take off the cap and its protection from the bottle 6 Take the sample 7 Replace the cap 8 Label the sample and record it na notebook 9 Sampling from a water course Sampling from a well String and weighting stone for sampling from a well or other inaccessible place Cloth Alcohol and lighter Cotton wool and forceps e g hair tweezers Thermometer Cool box Important The 8 steps described here for sampling from tap not necessary for chemucal analysis but are absolutely necessary for bacteriological analysis They the only way to be su
50. 5mg kg Mode of action Contact or ingestion Formulation Powder to dilute 1 2 Wettable powder 50 70 Method of use Dusting powder Ready to use at the rate of 1 to 2g of active ingredient 100 or 200g of powder per m2 Wettable powder Dilute in water for a final concentration of 0 5 to 1 of active ingredient powder at 50 gt 20g litre powder at 70 gt 1kg litre spray at a rate of 100 mi m2 For use against Body lice mosquitoes cockroaches bugs fleas Cost Powder about 93 US kg 25kg metal drum Quantity to allow For treating 1 000 people for body lice 40kg losses Precautions Avoid inhaling dust masks for treatment team 26 Technical briefs Vector control Permethrin Pyrethrinoid Commercial names Ambush Coopex Stomoxin Toxicity rats LD50 430mg kg Mode of action Contact ingeshon Formulation Dusting powder 0 5 and 1 Concentrated solution 25 and 10 Method of use Dusting powder Ready to use Concentrated solution Depending on vector For use against Lice Impregnation of mosquito nets Cost Powder about 2 US kg 25kg bag Concentrated solution about 16 US litre Quantity to allow For treating 1 000 people for body 40kg losses Precautions Avoid contact with mucosa dust mask goggles Possible skin allergies Do not r nse with
51. Control methods Control is essentially by chemical methods even if cleaning dwellings and burning dust gets rid of eggs and larvae It 1s essential to determine the sensitivity to any given insecticide because of the many problems of resistance Bedding and clothes are treated with an insecticide powder Disinfectant products chlorine solution 4 cresyl etc are effective against eggs and larvae In the case of a risk of epidemic plague it is essential to destroy the population of fleas without harming the host species e g rat because of the risk of human infestation would be increased Control 15 done by puting insecticide powder on the rodent s trails or in their nests Permethrin 0 5 propoxur 1 or any other effective insecticide 15 used Organochlorines are generally ineffective The powder is laid down n lines 50cm long and 3mm wide near to a non poisonous batt to attract the maximum number of Todents Vector control The principal vectors biology and control methods Rodents General points Rodents make up about half the mammal population and thus play an important role as reservoirs of pathogens in the transmission of diseases to other mammals Domestic rodents and those of medical importance are composed essentially of three species of the munde family the black rat the brown rat and the mouse Metbods of transmission Pathogenic agents are transmitted by an ectoparasite of the rodent
52. RUNDFOS La pompe en agriculture Agn Nathan 1984 HCR Manuel des situations d urgence Premi re partie Op rations sur le lerram HCR Geneve 1982 HELVETAS COOPERATION SUISSE AU DEVELOPPEMENT Manuel technique pour l approvisionnement en eau des zones rurales SKAT ATOL 1981 HOWARD J Safe dr nk ng water Oxfam Technical guide Oxfam Oxford 1978 JORDAN T D Jr A handbook of grawity flow water systems Intermediate Technology Pubhcation 1984 LANOY J N ROY ML Manuel du technicien san tarre OMS Gen ve 1976 MARA D Sewage treatment hot cl mates John Willey 1976 MARA D The design of pour flush latrines TAG Technical note n 13 UNDP World Bank 1984 MARA D The design of pour flush latrines TAG Technical note n 15 UNDP World Bank 1985 MINISTERE DE LA COOPERATION Memento de l adjoint technique des travaux ruraux Munist re de la Coop ration Paris 1977 OMS Normes internationales pour l eau de boisson 3 me dition OMS Gen ve 1972 OMS Direchives de qualit pour l eau de boisson Volumes 1 et 3 OMS Gen ve 1985 OMS Techniques de base pour le laboratoire m dical OMS Gen ve 1980 Practical books recommended in the field VA 27 29 31 32 33 35 36 37 39 OMS Guide pratique pour l eau potable et l assamissement rural et suburban OMS Copenhague 1984 OMS Les lashmantoses OMS Gen ve 1984 OMS Lu
53. The excreted eggs of this category of helminths pass part of their life cycle one or several intermediate aquat c hosts snails crustacea fish before becoming nfectious to man Examples are schistosomiasis and flukes Control measures excreta disposal treatment before disposal in the aguatic environment control of intermediate hosts e g snails imgaton canals reduction of contact with potentially contaminated water correct cooking of fish and aquatic plants 5 Excreta related diseases transmitted by insect vectors This includes all the diseases in the previous category which can be transmitted by insects flies cockroaches etc and diseases transmitted by mosquitoes breeding in polluted water Culex quinquefasciatus which transmits bancroftian filariasis Control measures excreta disposal coupled with control of certam vectors The impact of an excreta disposal programme on health 15 difficult to evaluate It is generally agreed that a health impact will only be achieved if such a programme is linked to improving water supplies and individual and collective hygiene Choice of disposal technique There are many excreta disposal techniques In each situation the technique chosen should be adapted to the site conditions and the population concerned If this rule 15 ignored the system may quickly become unused and damaged and may even create a health r sk in itself In general the choice o
54. US Gal Weight TUS Gal 3791htres 8 US Pints ltonne 0 984 long UK tons 0 83UK Gal 11102 short US tons 1UK P nt 0 568 litre 20 fL oz z 2204 pounds Ib 105 Pint 0 473 litre 16 fl oz 1kg 22051b 10 02 28 41ml 352702 1g 0 0302 Mi weight at 16 7 so 62F 1UK ton 1016 22401 gt 1US ton 30715 200015 1UK Gal 1UK ton 11USton 105 Gal 833 Ib 04kg 1602 453 6g Temperatures loz 2835g From Centigrade to Farenhet multiply by 18 9 5 and subtract 32 From Farenheit to Centigrade add 32 and mult ply by 0 555 5 9 0 F 178 C 32 F orc 50 F 10 C 68 F 20 C 984F 36 9 C 104F 40 IV 10 IV Materials and work estimates Materials and work estimate From Handbook of Gravity Flow Water Systems 18 EXCAVATIONS A A MI Ordinary sol mn a sar 0 55 man days m d Gravelly sol nn em im 077 m d Boulder mme 110m d Medium rock cutting m nue 1 60 m d Hard rock cutting mamo 250 m d WOOD WORKING u men men en een Per m of finished wood Skalled labour sm 18 men day Unskalled labour n umee un men ee 18 men day STONE AGGREGATE PRODUCTION ernennen Per m of crushed rock Unskilled labour nenn 14 men day CONCRETE men mm Per mt 1 2 1 1 3 mix Cement gt POR 033m Sand _ ween 0 900 me DS Aggregate ms AAA 100m Mason labour m
55. adult or imago feeds on plant sap Its varies from one to several months The maturation of eggs in the female needs a blood meal except for the first laying in Culex species Larvae may thrive in any water body except for deep water such as large river lake or sea Certain genera Aedes use sites where the water level is variable dependent on rainfall such as tree trunks or leaves Others are more specific to stagnant and heavily polluted water Culex The activity of the adult varies with species the sphere of action hours and places of activity type and specificity of food etc Thus in order to carry out effective control it 15 important to find out what species is concerned and what are its specific features Control methods ENVIRONMENTAL HYGIENE The main aim is to alter the environment so as to make 1t unfavorable for the reproduction of the species concerned Aedes aegypti This species is often associated with human dwellings where it breeds in any open container of water Control measures at getting rid of these types of sites or at protecting them with a cover or mosquito netting with mesh lt 0 7mm Large water containers should be frequently emptied at least once per week Culex Control measures to eliminate bodies of stagnant water loaded with organic matter e g in latrines or if not then to eliminate surface vegetation in stagnant water and ensure that these wat
56. ain precautions should be taken to preserve it never let it dry out and never pass chlonnated water through it Disinfection with chlorine Chlorine is a suitable disinfectant for water because it 1s very powerful without being toxic It allows the destruction of all viral and bacterial pathogens in water Chlorine can also be used to disinfect surfaces in contact with water the insides of wells pumps pipes spring boxes reservoirs etc when putting into service after repairs or after accidental pollution For this purpose it is used at much higher concentrations than for the disinfection of drinking water because the pollution may be much greater see techmcal briefs Chlorine generating products and Chlorination In the situations considered here gas chlorination is not recommended because it can be dangerous and is not practical on a small scale Chlorine generating products are preferred calcium hypochlorite chlonde of lime sodium hypochlorite solution see technical brief Chlorine generating products All these chemicals release chlorine when they are dissolved in water Chlorine reacts immediately with all the oxidizable substances which may be present in the water organic matter and certain mineral substances as well as pathogens and other organisms These substances consume chlorine For the chlorination to be effective sufficient chlorine must be added to meet this rutial chlorine demand This 1s confirmed by c
57. al major diseases It is important to consider water supply Sanitation and hygiene not simply terms of technical programmes but as an integral part of preventive health work in the same way as vaccination mother and child clinics home visiting etc The techniques described 1n this guide were chosen for their simplicity of implementation and maintenance They should obviously be adapted to each situation according to local conditions and resources available manpower materials money It should always be borne in mind that however good the techniques in theory it is only when they are correctly used that they can have any impact on health However important it is to produce appropriate technical solutions the necessity for complementary activities such as health education training of local technicians etc can never be too highly stressed In addition to technical knowledge which can be found in many technical reference books the work of the san tar an demands a good knowledge of the population being worked with and local hygiene practices Openess a few teaching skills and a sense of humour are a great help To conclude with a sanitation structure or programme should follow the rule of the three A s acceptable socially appropriate technically affordable financially A few facts The object here is not to produce a medical text but it is useful to give some scale to the problems linked to wate
58. an impact on the health status of a population They provoke an increase in the incidence of numerous diseases due to a lack of hygiene Good personal hygiene requires a sufficient quantity of water The diseases linked to a lack of water for personal hygiene called water washed diseases are DERMATOLOGICAL AND OPHTHALMIC DISEASES Dermatological and ophthalmic diseases directly due to a lack of hygiene such as scabies trachoma conjunctuv tis etc DISEASES TRANSMITTED BY LICE Lack of personal hygiene and washing of clothes encourages the proliferation of lice which in addition to the problems caused by their presence itching and scratching skin sores are disease vectors They transmit louse borne typhus and recurrent fever FAECO ORALLY TRANSMITTED DISEASES A lack of hygiene particularly of hands and food allows the transmission of these diseases from infected individuals sick people or carriers to uninfected individuals These so called dirty hands diseases are diarrhoeas and dysenteries bacterial protozoan or viral cholera typhoid and paratyphoid fevers hepatitis A poliomyelitis and various helminth diseases Most of these diseases can spread epidemically in concentrated populations Problems due to poor chemical water quality Water may contain numerous dissolved chemical substances which come either from pollution fertilizers insecticides industrial waste etc or from the composition of th
59. anding at the spring collect the running water with a split bamboo for instance Erect a protective barrier around the spring 10 metres above it Dig a drainage channel 10 metres above the spring to avoid it being polluted by run off As soon as possible Build a spring box Certain measures for the protection of water po nts can and should be taken during the very first days Others require particular materials equipment and skills and should only be envisaged at a later stage though as quickly as possible Do not wait to be able to solve the whole problem before starting work every step taken is an improvement 1 11 Water in camps Water supply Note F cal pollution of water may occur at any stage between its origin and its consumption For example for water from a well there may be pollution of the water table pollution of the water inside the well from soil run off etc pollution during transport from dirty containers dirty fingers etc pollution dur ng storage in the home from insects dust people taking water with d rty recipients etc Consumption of clean water can only be achieved by action at all levels with a global programme of water point protection excreta control and health education which 15 a long term programme Pollution at the source or during collective transport is nevertheless more dangerous than pollution in the home because it a
60. ation is used 1n the following techniques soakaway pit infiltration trench evapotranspiration area irrigated garden WASTE STABILIZATION PONDS Waste stabilization is a biological process which takes place in ponds arranged in series It is an effective technique for the el m nat on of pathogens and is relatively easy to ma nta n but the design and implementation should be left to speciahsts or the result may be an almost insoluble problem It may be assumed that with a series of three ponds and a retention ime the ponds of 11 days a reduction of 99 9 in the number of feecal germs may be achieved The reuse of wastewater for irrigation after treatment in ponds may be useful provided that the following rules are followed ensure that irr gation is not likely to create areas of stagnant water irrigate crops which are not in contact with the soil e g fruit tree or which are cooked before eating II Sanitation Collection and disposal of refuse Collection and disposal of refuse Introduction The accumulation of household waste creates a public health refuse as well as a pollution problem The health risks are essentially to do with the encouragement of insect vectors and rodents the breeding of flies which play a major part in the transmission of feeco oral diseases mosquitoes of the Aedes genus which lay eggs in water lying in empty tins drums tyres etc and which are
61. atrine simple or alternating twin pit is at least two years Conclusion The designs shown in the techrucal briefs which follow represent the most simple and common techniques of excreta disposal trench latrines suitable for emergency situations simple pit latrines ventilated or not the most frequently used twin pit emptyable latrines surtable for public facilities pour flush latrines more sophisticated suitable where there is plenty of water and where the population is familiar with this technology flushing toilets with septic tanks sometimes seen in hospitals but which need constant running water This is just a quick review of disposal techniques There are variations which allow adaptation to local conditions In general terms an excreta disposal technique may be considered acceptable when it contains the excreta in one place it does not create an attraction for insects it is not a source of pollution of water points it is accessible to users it gives a minimum of privacy it is adapted to local habits Sanitation Removal and treatment of wastewater Removal and treatment of wastewater Introduction Nothing is lost nothing is created everything is transformed This principal applies equally to water 1t is the source of l fe much effort is spent to get it but it also is a source of death and it is essential for health that the sam
62. blueprints for shelter layout exist but the cultural habits of the population or populations concerned should be the principle guide Avoid layouts in lines and rows they increase distances to latrines and water points isolate families by depriving them of personal space and use more land than the models proposed here On the other hand this method can be implemented quickly and 1t is better than no planning at all Plan by community unit the basic unit is formed by grouping from 8 to 16 shelters in a square or rectangle around a communal space latrines water points and washing areas may be placed the centre or round the outside Plan by squares the basic unut is formed by groups of 4 shelters a square with a latrine in the middle By grouping these basic units in lines and rows the blocks of houses and the sections are established Site Planning In both cases spaces for activity areas and services are created by leaving out a number of basic units according to the space required Some quantified norms Area available person 30m Dwelling space person 35m Number of people water point 250 Number of people latrine 20 Firebreaks 75m every 300m Distance between two tents 2m minimum Distance between two rows 10m Type of dwelling Tents are often used during the initial phase Apart from the fact that tents do not last long they are expensive to buy and t
63. bution point as far away as possible from the tank Use the rope in the kit for fenang Do not lose the connection spanner if it does get lost there are some in the MSF water supply tool kit white bucket When rationing water the gate valves on the outlets may be closed and the knobs taken off Be careful not to lose the knobs After use t 15 essential to clean and dry the inside of the tank before repacking to extend its open the valve and the filling cap unscrew the plastic corner reinforcing plates on one side of the tank push a piece of string or wire between the plates and retighten them hang up the tank by the string or wire slip a piece of wood for example between the filling opening and the tank bottom to keep the inner surfaces apart and let asr arculate inside Do not fold up the tank until the inside is completely dry 2 3 days at least To repair the tank use the repair kit supplied and follow the instructions carefully 1 51 I Water camps Technical briefs _ DISTRIBUTION TAPSTAND KIT Technical briefs I Water camps Distribution tapstand Method The distribution tapstands are pre assembled and quick to install allowing rapid provision of water distribuhon points m emergency situations The kit 1s composed of 2 tapstands each unth 6 self closing taps The tapstands are designed to be used unth the water storage kits or any other system fitted unth DN50 connections Installati
64. carriers of malaria which is much more effective than using an untreated net Choice of insecticide Deltamethrin 2 5 EC or WP Or f not permethrin 20 or 10 Dose Deltamethrin 25 mg of active ingredient per m of cloth minimum 15mg m Permethrin 200 to 500mg m2 Impregnation method 1 Determine the total area of the cloth 2 Determine the volume of water absorbable by the cloth dip several identical mosquito nets a known volume of water then wring lightly measure the reduction in the volume of water and divide this volume by the number of mosquito nets the average is about 15ml per m2 3 Dilution Determine the quantity of active ingredient per mosquito net multiply the dosage of active ingredient per m by the area of the nel then determine the corresponding volume of concentrated solution and thus the factor of dilution volume of water volume of concentrated solution Example area 18 7m2 dose of active ingredient 25mg m product delthmethrin 2 5mg m2 volume of concentrated solution 467 5 x 100 2500 18 7ml volume for impregnation of mosquito net 280ml dilution 280 18 7 or 1 15 4 Impregnation One net Put the mosquito net in water hght plastic bag Add the pre determined volumes of water and insecticide for that mosquito net Close the bag and knead well to ensure good impregnation then take out the mosquito net and leave it to dry pref
65. ccumulaton rate will be about 0 04m per person per year Thus for a group of 25 people the maamum number per latrine recommended by WHO t needs a pit of at least 0 04 x 25 Im per year of use 3 If a cement slab is to be used it should extend at least 15cm beyond each slde of the pit to ensure a secure seating 4 Make a slab see technical brief Latrine slab and place it over the If the soil 15 unstable it may be necessary to build a foundation to strengthen the pit walls before plaang the slab 5 Construct the superstructure It may be built with bricks earth wood plastic sheeting etc but preferably local matenals The superstructure should have a door if local habits dictate Otherwise a spiral form may be used 6 Fix a roof with the slope towards the back of the structure 7 Dig a drainage channel around the latrine to prevent run off entering and to protect the walls of the pit Key Inputs Effective volume of pit Defecation hole Shovel pick miner s bar Slab Slab see technical brief Cover Superstructure Cover wood metal or concrete Roof Material for superstructure and door Slab seat ng Drainage channel Water table Example of a concrete slab see brief Possible alternative slab of logs covered with Soil to make maintenance easier quality of wood 15 important aging termutes danger Important Try to ensure that the cover 15 always replaced to avoid breeding of flies and bad smells a
66. ced because the poisoning is chronic Here again the remedy 1s prevention information and education HI Vector control The principal vectors biology and control methods The principal vectors biology and control methods Mosquitoes Lice Flies Fleas Rodents General introduction Knowledge however small of the biology of each vector is a sine quae non of effective control measures It is useless to try to combat body lice by treating the hair or to try to control Culex larvae by treating clean standing water It is vital to know how where and when to act Nevertheless it is possible to identify some principles common to all vector control programmes The aim should be to make the local environment unfavourable for the development and survival of the vector environmental hygiene Combat is generally more effective if it is focused on immature forms of the vector Complete eradication 15 frequently unattainable the objective should be to keep the vector population below a level at which it poses a too great risk of an epidemic 1 4 The principal vectors biology and control methods Vector control Mosquitoes Mosquitoes form the largest group of vectors of medical importance with more than 3 000 species Their life cycle is closely linked with water Life cycle There are four stages of development The first three are aquatic egg larva nymph and generally last for two weeks The
67. chia col E Coh 1 13 Water m camps Assessment of water quality These germs are always present large numbers in the f ces of man and other warm blooded animals The presence of f cal coliforms an water indicates the possible presence of pathogenic organisms The absence of f cal cohforms in water indicates the probable absence of pathogens but 15 no proof of thus certain pathogens are more resistant than f cal cohforms The count of faecal coliforms or E Coli per 100 ml gives an indication of the degree of f cal pollution Note Other bacteria very similar to f cal coliforms live more or less everywhere in the environment They also belong to the coliform group Col form group F cal coliforms principally E Coli total coliforms Other coliforms In raw water untreated only the presence of f cal coliforms is significant for health because they are the only coliforms wh ch prove f cal contamunation Although in certain cases total coliforms are identified only f cal coliforms are used as indicators in the field Method of bacteriological analysis The membrane filtration method is generally used This consists of filtering the water through a membrane which retains bacteria The membrane is then incubated at 44 C for 14 18 hours on a specific culture medium The count of those colonies which develop with a characteristic appearance gives the number of f cal coliforms n the sam
68. chniques for disposal of excreta waste water and refuse which improve environmental san tation and thus create sanitary barriers A Excreta disposal B Removal and treatment of wastewater Collection and treatment of refuse D Technical briefs Excreta disposal Sanitation Excreta disposal Introduction The term excreta includes urine and faeces The main objective of excreta disposal is to reduce the transmission of diseases due to environmental contamination by faecal matter or the proliferation of vectors In an emergency situation steps must be taken immediately particularly where there is a large concentration of displaced people The methods of excreta disposal which apply to refugee camps as well as rural situations are generally simple and cheap The choice of method will be decided more by local practices and socio cultural factors than by technical considerations Excreta related bealtb risks Many infectious diseases are transmitted by human excreta The pathogens leave the body of the infected person in the excreta and contaminate one or more healthy individuals Urine is less dangerous than feeces except in the case of one type of schistosomiasis Schistosoma haematobium typhoid paratyphoid and leptospirosis e g where water is contam nated by rat urine Five types of excreta related diseases or transmission routes may be identified 1 transmission Pathogens are trans
69. cm allow 10 rings for 7m of well depth over _ Im eable concrete rings ri concrete mngs tor2 Anchonng collar on concrete ring 7 over which His on the top ring Apron Handpump with fixtures and fittings Permeable concrete ring Construction materials for the drainage system Gravel layer about 10cm see technical brief pit 1 2 3 4 5 6 7 8 9 10 n 12 13 14 15 16 Important Respect safe minimum distances no latr nes closer than 30m from a well Latines should absolutely be downhill from the well Maintenance should be done carefully the pump the apron repair possible cracks the drainage system clean out the channel regularly Before the first use or after accidental pollution disinfect the well with a chlorine solution as described below For the preparation of 1 chlorine solution see technical brief Chlorine generating products possible to empty the well Empty the well brush the sides above the water level with a solution of 200mg of chlorine per htre 2001 of 1 soluton 1 leave for half an hour and let the well refill If t is not possible to empty the well 1 Brush the walls above the water level with a solution of 200mg of chlorine per tre 2 Determine the volume of water in the well vol x x 1x h x 3 14 radius of well h depth of water or height of water column 3 Add 10litres of 1 chlorme solution see tech
70. ct m p rim phos methyl 1 to 2g active product m Aenal application Confined to specialists 6 The principal vectors biology and control methods Vector control Lice Only the body louse is a potential vector It is found almost exclusively between the skin and clothes Transmission of possible pathogens through the louse s excretions e g typhus or by the louse being crushed e g recurrent fever The louse population may grow when personal hygiene is poor lack of water soap or clothes where there is overcrowding and when it is cold A situation of a risk of epidemic may be reached demanding emergency measures including the use of an nsecticide Before any action is taken a study of the resistance of the lice to insecticides should be done by a competent laboratory or by an experienced person in the field In the absence of resistance which is rare DDT or malathion may be used If n doubt propoxur or permethnn is almost always a good choice Powder is used as treatment of the body The concentration depends on the product but 30g of powder per person is the standard dose Powder is applied to the fully clothed subject at the neck half at the front and half at the back then spread by rubb ng Pay special attent on to belts and socks if these are worn Bedding blankets and clothes may also be treated a plastic bag for example Every bout of fever or large drop in temperature e g on death
71. d Notes When f cal pollution is noticed the first thing to do is to try to trace its source in order to prevent it rather than to treat the water It is generally an illusion to rely on water treatment at the domestic level with techniques such as storage boiling and filtration If water must be treated the only reliable method is treatment on a collective scale 1 17 Water camps Simple water treatment Simple water treatment Storage sedimentation Storage 15 the simplest procedure to improve water quality certain pathogens do not survive beyond several days but it needs large reservoirs Storage alone is not always a very effective procedure During storage there also occurs purification by sedimentation Suspended material settles to the bottom of the reservoir with a proportion of the pathogens mainly the largest helminth eggs and protozoan cysts Sedimentation of turbid water 15 essential before filtration and disinfection If natural sedimentation is too slow flocculation may be necessary specialist help 1s needed for this In practice f water in a bottle 1s still muddy after an hour then the natural sedimentation will not be enough Filtration Passing water through a permeable bed eliminates a proportion of the pathogens by Tetaining them mechanically on the surface or within the filter Ceramic candle filters and certain sand filters known as rapid sand filters work on this pri
72. d with the k t or a distribution tapstand there are 2 stands each with 6 taps in the MSF Distribution tapstand kit Install a drainage system around the platform and around the distribution point to avoid rapid deterioration of the site Key Inputs Reservoir bladder tank Filing opening with cap 2 people per kit for installation Outlet valve One half of a DN50 connection Guillemin system Distribution points g MSF tapstand kits with 6 Groundsheet taps 6m of 2 reinforced hose DN50 suitable for carrying drinking water Harness for transport by car or lorry Serflex collars for grip and watertightness Spanner for loosening and tightening the hose connections 1 4 turn distribution valve Corner protection plate Means of filling motorpump lorry tanker etc Important Site the distribution point as far away as possible from the tank Do not lose the connection spanner if does get lost there are some in the MSF water supply tool kit white bucket After use t Is essential to clean and dry the inside of the tank before repack ng to extend its open the valve and the filhng cap unscrew the plastic corner remforcing plates on one side of the tank push a piece of string or wire between the plates and retighten them hang up the tank by the string or wire shp a prece of wood for example between the filling opening and the tank bottom to keep the inner surfaces apart
73. e II 56 Sanitation Technical briefs w lt lt _ _ _ _ _ 2 i N e ego a AE 08 ae 1 16 Technical briefs IT Sanitation Method Trench latrines represent a method of excreta disposal which ts simple and rapid to mplement but temporary They are only justified in emergency situations until more permanent solutions are unplemented Installation Choose a site away from water points gt 30m and downhull from them Dig trenches about 30cm wide and 90 to 150cm deep Allow about 3 5m per 100 users Place the excavated soil near the side of each trench so that the users can cover their excreta with soil after each use to reduce the attraction of flies Lay planks down the two sides in order to ensure a good foothold and to Umit erosion of the trench edges When the excreta reaches about 30cm from the surface fill in the trench with compacted earth Mark the spot and dig another trench Fence the area for example with plastic sheeting and put up a zigzag entrance in order to limut the risk of straying of animals and to keep as much privacy as possible for users Put a water container with a tap and soap in an obvious place near the exit to allow the washing of hands after defecation Key Inputs Fence plastic sheeting Shovels picks Water container with tap and soap Planks or wooden poles Stones for drainage Stakes for th
74. e camp Schmutzdecke Schmutzdecke Schmutzdecke Biological layer playing a punfying role at the surface of a slow sand filter Sedimentation S dimentation Sedimentaci n Process of deposition of suspended setthng solids in water by gravity Septic tank Fosse septique Fosa s ptica Tank for collection and part al treatment of household wastewater before disposal by sub surface drainage Sewage Eaux vannes Aguas negras Wastewater from sanitation installations containing excreta Slow sand filtrabon Filtration lente Filtraci n Water treatment technique which lenta en arena combines mechanical filtration sand with biological purification see Sckmutzdecke Soakaway pit Puits perdu Pozo de Hole filled with stones used for absorci n infiltrahon of wastewater Sodium Hypochlorite Hipodonto Chlorine generat ng product hypochlonte de calcium de calcio with 5 to 15 available chlorine much less stable than solid products Sodium Thiosulfate Tiosulfato Crystall ne chemical substance used for thiosulphate de calaum de sodio dechlorinahng drinking water Spring Source Manantial Ground water which flows naturally to the surface Standing stagnant Eaux satgnantes Aguas Water from rain or human activities water estancadas which stays on the ground surface Technical IV Glossary English French Spanish Definition Sterile St rile Est rl That which contains no germs or any other form of life Sterilization St rilisation Estenl
75. e effort is made to remove it after use Health risks and nuisance These r sks are due to organic and biological pollution carried by wastewater as well as the presence of stagnant water breeding of insect vectors anopheles culex spread and multiphcation of pathogenic agents such as cholera vibrios and schistosomonas etc chemical contamination of water nitrates detergents and ecological disturbance of aquatic environments production of noxious and corrosive gases Definition of wastewater The risks associated with wastewater depends on its origin and it 1s useful to classify the important sources Domestic wastewater Sewage water carrying excreta in suspension thus containing bacteria viruses and f cal parasites and also nitrogen Sullage water from the bathroom the kitchen laundry etc containing detergents and fats as well as micro organisms of f cal origin Agricultural wastewater Stockraising effluent slurry and manure Crop growing activities fertilizers and pesticides It is usual to measure the degree of pollution by the following parameters Daily volume of effluent Chemical Oxygen Demand COD a measure of the total organic content Five day Biological Oxygen Demand BODS5 the organic content biodegradable within 5 5 Total Suspended Sol ds TSS Nitrogen content ammonia and organic nitrogen Phosphorous content 8
76. e fence Zigzag entrance Plastic sheeting or local material Planks Empty cans to handle soil for burying excreta Trenches width 30cm depth 90 to 150cm Water container e g 2001 drum with tap Soil for burying excreta Soap Important The planks may be replaced by wooden poles which should be buried several centimetres Ensure that living areas not downwind of the trench latnnes It is usually necessary to build separate trench latrine areas for men and women Simply separating the male and female sections with plastic sheeting and providing two separate entrances may not be enough from the point of view of acceptability to the population The objective should be to replace the trench latnnes as quickly as possible with a more hygienic system eg ventilated pit latrines see the other Latrines technical bnefs I 17 Technical briefs Sanitation SIMPLE PIT LATRINE 18 Technical briefs IL Santtation The simple pit latrine 15 one of the simplest and cheapest means of disposing of human wastes If well designed and built correctly sited and well maintained tt contributes significantly to the prevention of faeco orally transmitted diseases Construction 1 Choose a site downhill from groundwater abstraction points and at least 30m away the latr ne or group of latrines should be not less than 5m and not more than 50m from the dwellings 2Dig a pit assuming that the solids a
77. e made of local material g logs covered with earth but for more durable latrines a reinforced concrete slab 1s easy and relatively cheap Construction Make a mould of metal or wood with internal dimensions the same as the slab Coat the inside with an oily product such as used engine oil to avoid the concrete shcking to it Place the mould on a flat surface which Is covered by a layer of sand plastic sheeting paper etc Cut the steel bars to length and join them together with wire Make a wooden or metal template for the defecation hole oil its surface and place t m the mould Mix the concrete 1 volume of cement to 2 volumes of sand and 4 volumes of gravel Cast a thickness of about 25mm of concrete the mould and level the surface without smoothing Place the reinforcing steel on the surface Cast the rest of the concrete and smooth the surface making a curve round the defecation hole useful when cleaning the slab Position footrests e g bricks Optional If possible attach handles of bent steel bar to several parts of the slab to ard carrying Cover the slab with jute sacking or plastic sheeting and spnnkle regularly with water to keep t damp during curing After 24 hours remove the template from the defecation hole and recover Take out of the mould and install after 4 to 6 days curing in the shade Key Inputs Cement 1 3 bag Defecation hole Sand Gravel
78. e population has enough containers jerrycans buckets etc for the collection and storage of water otherwise a distribution will be necessary If a sufficient quantity of water is not available near the site moving the camp should be considered Quality The water should be harmless to health and have an appearance and taste acceptable to the population Ideally the water supplied should meet the water quality standards of the WHO However in practice it is often necessary to supply water which does not conform to these standards simply because there is no alternative 1 3 Water in camps Needs COMMENTS The quantity of water available has relatively more importance than its quality It is preferable to have a lot of water of average quality than little water of very good quality The lack of water to ensure a minimum of hygiene entails even more problems than does the consumption of relatively poor quality water Water quality is important for drinking water but is of less importance for other uses except where there is a risk of schistosomiasis It is sometimes possible to supply water of two different qualities but this generally entails more disadvantages than advantages 7 14 Water related health risks 1 Water in camps Water related health risks Problems due to a lack of water In extreme cases of lack of water life is simply not possible dehydration and death Less extreme shortages also have
79. e rocks themselves fluorine arsenic iron etc Water in camps Water related health risks These substances may give the water such a bad taste that it is undrinkable for example if it contains too many salts or too much iron but it may also in the long term cause severe health problems for example methaemoglobinaenua in babies due to high n trate levels arsenic poisorung etc The possible presence of toxic substances in water is something which must be borne in mind but n the situations considered here the microbiologlcal quality of the water is a much more important and preoccupying problem Problems due to poor biological water quality Water may contain numerous pathogenic organisms and thereby become a means of transmission for many diseases Typhoid and paratyphoid fevers nn bacteria Hepatitis virus Cholera Poliomyelitis Diarrhoeas caused by Escherischia Colt salmonellas and Yersinia Enterocolitica Viral gastroenteritis ss cessent dysentery caused by various species of shigellas bacteria Campylobacter dysentery ses crie bacteria Amoebic dysentery seen protozoa Giardia lambliasis 1 eese eee eee enses ee eene eee en serene to sossa naso sos ossa cel protozoa
80. e trap The removable cover should fit well on the trap and be sufficiently heavy to avoid unauthorised opening children Key Resources Watertight casing Detailed construction plans Removable cover Casing in bricks or cement Inlet elbow 90 Cement sand gravel Outlet tee Shuttering timber Inlet 6mm reinforcing steel Shovel and pick Separating partitions Bricklayer s tools Middle zone separation of fats 10mm PVC pipe elbow and tee Settled solids NI ND Important Effective volume The effective volume of the grease trap should be enough to allow a retention time of the wastewater sufficient for the separation of oils and fats and the settlement of solids Asa general rule t may be considered that the effective volume should be double the hourly flow entering the trap Maintenance Good maintenance 15 the key to the effiaency of the grease trap Weekly clearung is recommended to brut odours Material removed by the trap should be buried 1 47 Sanstation Technical briefs IRRIGATED GARDEN 12 E Zi N id View from above II 48 Technical briefs Sanitation Irrigated garden Method Wastewater from water points may be used to rr gate vegetable gardens The most common method 15 flood or bas n irrigation The basins are periodically flooded and the water stays until t infiltrates into the soil Furrow or channe
81. e tube to vent the steam into cold water Close the valve again when the pressure drops to 0 1 bar 11 Fill the outer tank with cold water 161 12 Open the Blue valve the pressure reading falls because a vacuum is created inside 13 Wait for 10 muns and close the Blue valve Open the Red valve 14 Open the autoclave Wait for 15 to 30 mins with the cover half open to allow the matenal to dry completely 15 Take out the boxes and close the covers immediately Key Inputs Chimney Graduated water tank Bl and 161 1 autoclave and detailed instructions Blue valve Condensation coil Boxes with covers Ai Alter wath cotton wool Water 8 or 16 for stenlization plus 161 for Red valve drying Electric pate UNITE AE W Flexible pipe and container of cold water for Timer ven ng steam at the end of the cycle Pressure gauge Isolahon Se not used Indicator tape if available Safety valve Weights left 1 bar right 2bars Green valve bleeding Yellow valve for empty ng at the end of stenl zation Electric overheat ng safety cut out optional Electric elements Door for kerosene gas charcoal stove DONDURAN Important For more complete instructions refer to the user s guide for each model The timer acts only as a remunder It does not control the electricity supply Air bleeding step 6 must absolutely be done at least twice or sterilization 15 not complete The heating time 15 longer when n
82. early full 50cm from the top demolish it or move the superstructure and the slab to a nerghbouring place and fill the pit with soul Do not dig this place again for at least two years Alterative method if the subsoil is very rocky or if the water table is very high and it 15 not possible to leave 1 5m between the bottom of the pit and the groundwater level t 1s possible to dig the pit partially n a very well compacted earth mound In this case the above ground part should be lined with bricks or stones Do not use a cover on the defecation hole this prevents the circulation of air Do not forget the mosquito netting which traps flies at the top of the pipe where they die Use a synthetic or painted metal mesh because the gases which escape via the pipe are corrosive to metal The VIP latrine should be built a clear space away from trees which impede air movement Pay attention to the wind direction so as not to cause an odour nuisance 21 Sanitation Technical br efs TWIN PIT LATRINE Plan view Technical briefs Sanitation Method Twin prt latrines may be used in places where toilets have to last for a long time so as to economise space public places health structures etc and as a bonus to produce good quality organic manure The latrine 15 built on a lined pil divided two by watertight partition wall Both pits are used alternately and are emptyable As they are reusable the system 15 th
83. ectors and pests of public health importance WHO Gen ve 1984 WHO Equipment for vector control WHO Second Edition Gen ve 1974 WINBLAD U KILAMA W San tat on without water MACMILLAN London 1985 Practical books recommended in the field Notes Notes Notes Notes Notes Notes Notes Notes France Belgium Holland Switzerland Spain Luxemburg Greece M decins Sans Fronti res 8 rue Saint Sabin 75544 Paris Cedex 11 T l 33 1 40 21 29 29 Fax 33 1 48 06 68 68 Telex 042 214360 MSF F M decins Sans Fronti res 24 rue Deschampheleer 1080 Bruxelles T l 32 2 414 03 00 32 2 411 82 60 T lex 046 63607 MSF Artsen Zonder Grenzen Postadres Postbus 10014 1001 EA Amsterdam T l 31 20 520 87 00 Fax 31 20 620 51 70 T lex 044 10773 MSF NL M decins Sans Fronti res 3 Clos de la Fonderie 1227 Carouge Gen ve T l 41 22 300 44 45 41 22 300 44 14 T lex 045 421927 MSF CH M dicos Sin Fronteras Avenida Portal del Angel n 1 1 08002 Barcelona T l 34 3 412 52 52 Fax 34 3 302 28 89 T lex 052 97309 MSF E M decins Sans Fronti res 70 Route de Luxembourg L7240 Bereldange T l 352 33 25 15 Fax 352 33 51 33 Giatri Hons Synora 10440 Athenes T l 30 1 88 35 334 Fax 30 1 88 29 988 4 gt bigre
84. ed diseases is those with an insect vector wich develops or lives near to water for example malaria dengue and yellow fevers and onchocercias s The solution to these problems lies among other things with the choice of site for a settlement and with environmental hygiene measures drainage elimination of stagnant water covering reservoirs etc They will not be considered in more detail here In terms of health It is of primary importance that the population should be able to use a sufficient quantity of water to allow a minimum of hygiene in addition to use for cooking This means that the water should be available in sufficient quantity and easily accessible and that people should have enough water containers In terms of water quality The major danger is pollution of water by f cal matter Everything possible should be done to prevent such pollution Nevertheless it is preferable to have a lot of water of average quality than a little water of very good quality 1 7 I Water camps Water related health problems Water related bealib problems Skin diseases scabies mycosis etc and ophthalm c diseases conjunctivitis trachoma etc Sometimes a major problem Louse borne typhus typ Recurring fever Lack of hygiene Lice Faeco oral diseases diarrhoeas typhoid cholera polio hepatitis A certain helminthiases POOR MICROBIO LOGICAL QUALITY Faecal pollu
85. ement Removable slabs for emptying pits Sand gravel Ventilation pipe Material for superstructure and door Twin pits Ventilation pipe and mosquito netting if latrine is Mosquito netting to be VIP type Gaps for the passage of liquids 1 experienced builders and 1 or 2 labourers Important The correct size of each pit s essential each one should permit the storage of faecal material for about 2 years during which period possible pathogens contamed in it are destroyed biodegradation Certain authors recommend one year only although it 15 known that Ascans worm eggs need more than one year to be destroyed As this technique demands the handling of faecal material during pit empty ng even if the matenal is so decomposed that it ls neither offensive nor dangerous t is important to know before choosing such a system 1f it can be acceptable to the population to do tius work Sodal religious and or cultural factors may forbid it and demand the use of another method The compost taken out may be used to fertilize crops or if not should be buned It is perfectly possible to build ventilated latrines on twin pits Important each pit must have its own ventilation pipe Remember to provide workers emptying the pils with protective clothing at least boots and gloves household glove type Sanitation Technical briefs Technical briefs San tat on Method A latr ne slab may b
86. engine is fitted with a low oil secunty system The diesel motorpump k t is suitable for fixed installations and for long pumping hours The maximum delivery 15 40m gt hour The total pumping head is 28m The fuel capacity 15 4 which gives 4 hours runrung The motorpump is mounted on a trolley and weighs 58kg Warning the diesel engine does not have an oil level security system check the oil level every day before starting up Every motorpump k t is supplied with 4 lengths of 2 Heliflex pipe 1 strainer 1 non return valve 1 float for the strainer 1 201 jerrycan for fuel 1 can of engine ou 1 funnel 1 too kit with spare parts for normal servives a user s manual and a maintenance logbook The recommended conditions of use and the maintenance practices should be followed pumping hours frequency of changes etc so as to avoid breakdowns which might interrupt an emergency water supply Where the motorpump is to be used for long periods n a fixed position shelter it from the weather The kit is a complete unit Its component parts should not be separated The whole kit should be repacked in its orginal case if it 15 to be stored again or sent elsewhere 1 55 I Water in camps Technical briefs Ld 1 56 Technical briefs I Water in camps Method Important 1 57 II Sanitation This chapter describes the health risks created by inadequate san tat on t suggests some simple te
87. er bodies are at least 1 2 m deep Anopheles Control measures are identical to those for Culex although Anopheles have a wider distribution Land drainage and filling also has an impact but thus 15 rarely possible Vector control The principal vectors biology and control methods However it may be necessary to couple these environmental hygiene and improvement measures with chemical control of larvae and adults In thus case the relevant government department should be called n as the misuse of insecticides particularly in the aquatic environment may cause irreparable ecological disturbance and favour the development of resistance etc In the case of a viral epidemic encephalitis yellow fever etc individual protection should be done by using mosquito nets mesh diameter less than 0 7mm on openings of houses and over beds repellent creams and lotions see page 32 CHEMICAL CONTROL Larvicides fuel oil spread over the whole water surface little used paraffin 301 ha 1 glass latrine week malathion 224 to 692g active product ha temephos 56 to 112g active product ha deltamethnn 2 5 to 10g active product ha Chemicals formulated in granules or in emulsifiable concentrate Adulticides Persistent treatment deltamethrin 0 05g active product m malath on 1 to 2g active product m permethrin 0 5g active product m propoxur 1 to 2g active produ
88. er by bucket over a period of 4 to 5 hours continuously Place a layer of gravel at the bottom of the well see technical brief Protecting a well Cement the Joint between the top edge of the highest ring and the cement plastered section of the well Install a system to draw water from the well and the protection see technical brief Protecting a well Before use the well should be disinfected using chlorine solution see technical brief Protecting a well Inputs 1 shovel 1 pick 1 miner s bar 3 beams about 2m long and 1 pulley 3 builder s buckets Mason s tools Sections of wire mesh with cement coating Rope diam over 10mm about 60m Cement about 1 bag per 3m of well depth Wire mesh chicken mesh type Sand 0 15m3 per 3m of well depth Bottom section of reinforced cement lining Perforated or porous concrete rings 3 or 4 Gust above the water level Material and tools for well protection see First concrete ring technical brief Joint between reinforced cement lung Mechanical pumping system if the flow of and concrete rings water 15 too great to keep the well empty by Gravel bucket during the work Bucket Important Well digging should only be done at the end of the dry season except an emergency when the water table is at its lowest to avoid the nasty experience of finding the well dry after just a few months of use Hand digging a well without supporting the sid
89. erably flat to avoid dripping and the movement of the insecticide to the bottom of the cloth Replace the mosquito net in the bag for storage and distribution 33 Vector control Technical briefs Several nets After having determined the dilution factor prepare a volume of insecticide solution sufficient for the number of mosquito nets to be treated Dip the nets then wring lightly and proceed as above These operations should be performed by staff trained in the use of insecticides Take care when disposing of excess solution to avoid damaging aquatic life and affechng water quality Choose coloured cloth which dirties less easily and which is therefore washed less often Persistence depends on the product and the climate but mostly on washing a persistence of six months 15 realistic in most cases if the net is not washed IV Glossary conversion tables and estimations A English French Spanish glossary B Conversion tables Materials and work estimations Glossary English French Absorption Absorption AccumulaHon rate Taux d accumulation Actvated carbon Charbon actif Adsorbent Adsorbent Altemat ng twin Latnne fosse double pit latrine Apron Tablier Available chlorine Chlore actif Aquifer water table Nappe phr atique Autodave Autodave Bacteria Bact ries Bacteriological Analyse analysis bact riologique Spanish Absorpci n Tasa de acumulaci n Carb n
90. eral candles provided they are not clogged Pump filter also called Katadyn Here the water is forced through the filter under pressure using a small integral handpump thus improving the flow Put the end of the plastic pipe into the water to be filtered and pump Inside the candle there is activated carbon which adsorbs dissolved substances and takes away any possible taste from the water Tap filter In this unit the candle is mounted inside a cylinder It is hke the siphon filter candle but filled with activated carbon plastic hose is connected to the tap When the tap is turned on water fills the transparent filter body passes through the candle and comes out of the spout Important thus filter can only be used where there is enough pressure in the p ped water supply Key Water to be filtered Ceramic candles S phon tube Collecting filtered water Container of water to be filtered Ceramic candle fastening and rubber washer Tap Cover Transparent filter body Outlet for filtered water Handpump Fastening collars Flexible tube raw water Strainer to prefilter raw water Universal tap fitting 1 2 3 4 5 6 7 8 9 10 11 CERTES Inputs Siphon filter Ceramic candle with flexible siphon tube Gravity filter 2 containers metal or plastic Ceramic candles 2 or 4 with rubber washers and wing nuts Tap Katadyn Kit containing 1pump fiter with flex
91. eration apply as those for the temporary incinerator see corresponding technucal bnef It is important that one or two people are responsible for the operation and maintenance of this type of equipment 39 IT Sanitation Technical briefs SOAKAWAY PIT Diameter or length 1 3 m Technical briefs Sanitation Soakaway pit Method A saakaway pit allows the disposal of wastewater from a water point kitchen shower etc by infiltration into permeable soil Construction 1 Choose the site at least 6m from dwellings 3m from trees or hedges 30m from groundwater points if it 1s a domestic soakaway pit 2 Determine the dimensions of the soakaway pit according to the quantty of wastewater to be infiltrated and the permeability of the soil 3 Dig the trench for the Inlet pipe diamater 50 to 100mm with a slope of 1 300mm wide and 300mm deep 4 Dig the pit to the required dimensions Measure the depth from the bottom of the incomung trench If the pit 15 deep and or the soil 1s unstable support the sides during digging 5 Fill the soakaway pit with stones up to the level of the trench bottom The stones should be clean with a diameter of 5 to 15cm 6 Lay the incoming pipe 1 slope Clear the stones around its end to create an empty space to aid dispersal of the flow 7 Place a large flat stone over the pipe and add a 10cm layer of stones 8 Cover the stones with straw or plastic sheet and fill in the hole
92. ere may be a village upstream As soon as possible use other sources wells spr ngs boreholes or at least pump the water so that people and animals do not have direct access to the water course Water supply 1 Water in camps Well protection Immediately and this does not require any particular materials or skulls Employ a watchman to monitor access to the well Surround the well with a fence against animals If it is used to water animals make a channel to take water to a trough situated outside the protective fence Forbid the use of personal water containers one with a single container should be provided for thus use Install a winch or similar system so that the bucket and are not laid on the ground and so that people do not lean over the well Keep sources of pollution such as latrines at least 30 metres away from the well and downhill from it if there is slope caution in certain hard fissured rocks 30 metres is not enough As soon as possible Make the improvements needed to prevent infiltration of run off make the upper part water tight to at least 3 metres depth install an apron a concrete slab on the head wall and drainage of the surroundings etc Cover the well and install a handpump or a self priming motorpump plan for maintenance and the supply of spare parts Spring protection Immediately Install a system which prevents water from st
93. es should only be considered in soils which are stable enough to be safe for the diggers If other wells in the area show the water table to be more than 30m deep or if there are good reasons to suspect the presence of a rocky formation between the surface and the water level then another technique e g drilling should be considered It is important to use local skills and knowledge when deciding where to site a well and which technique to use Skilled well diggers may often be found locally The technique described here based broadly on the GRET technical briefs is one of the simplest However it Is not suitable for all soil types e g sands Take care when siting a well to avoid possible sources of pollution see technical brief Protecting a well I Water in camps Technical briefs PROTECTING WELL UNPROTECTED il WITH APRON AND LINING Il PROTECTED WITH IV DISTANCE AND LAYOUT FOR HANDPOMP por e rine Kai Direction of run off Method A well should be protected as soon as it 15 dug This protection consists of preventing anything from getting into the well and preventing the infiltration of run off and wastewater which could carry contaminating material Lastly protection strengthens the structure of the well What to do 1 Line the whole well with concrete rings bought locally or fabncated see technical brief Fabricating concrete rings the lowest r ng should be porous or perforated The uppe
94. etc LAND RIGHTS Pay attention to legal and traditional rights Other points to consider are security the land area available the eventual possibility of self sufficiency for the population and the ease of supply of food and materials Site Planning 10 Basic principles Having chosen the site prepare map to see how much land is ava lable the surface drainage patterns and the areas for protection of water sources Give pnority to water and sanitation note drainage Determine needs for services and infrastructure Define the size of the camp and its sub divisions for camp management ideally 20 000 people in sub divisions of 5 000 Define responsibilities List the resources needed budgetary logistic human Needs Water and sanitation Roads Stores flour mulls distribution points Shelters type and number Adm rustrat ve structures screening registration etc Medical and nutrition structures Personnel accommodation Community facilities market cultural centre workshops schools recreation grounds cemetery etc Prepare a master plan of the camp All the structures should be marked on the initial map and the way that shelters are to be grouped should be decided This decision will affect the correct use of latrines and water points Security for the population is important as well as some re establishment of its social fabric Several
95. f an excreta disposal technique depends on cultural factors particularly local attitudes and practices concerning defecation the physical nature of the site soil type natural drainage rainfall patterns water resources the space available and locally available materials and skills 4 Excreta disposal U Sanitation A distinction may be made between emergency situations where immediate act on should be taken and chronic or long term situations where other factors dictating the choice of technique should be given more consideration EMERGENCY SITUATIONS When there is a large collection of people e g a refugee camp or where the normal sanitation structures are destroyed in a disaster t is essential to provide defecation facilities immediately These facilities are usually provisional and are progressively improved or replaced by more suitable structures as the situation develops A defecation field or area may provide an emergency solution particularly in hot dry climates and where there is enough space available Defecation fields should be clearly marked fenced if possible and protected against flooding They should be located downwind and away from living areas avoiding water courses and at a reasonable distance from water points minimum 50m If a bulldozer is available locally it is recommended that the ground is cleaned regularly and the f cal material is buried in a trench so that the area may be
96. ffects the whole population at once and consequently encourages large scale epidemics CONTAINERS FOR TRANSPORT AND STORAGE If the d splaced people have not been able to bring enough containers with them they cannot use the water which is provided for them Each family should have containers with a total capacity of 40 litres as a minimum If the people do not have enough containers it is vital to distribute them as a top priority Contamers with small openings like jerrycans with a cap are the most suitable because they are used by pouring the water and not by dipping into it which risks contaminating 1t each time Cooking oil is often distributed in such cans and they can be re used Traditional clay containers may be suitable as long as they are covered to prevent contam nation by dust and insects 1 12 Assessment of water quality I Water in camps Assessment of water quality Is the water potable or not The only cnteria really of importance to health are the presence or the absence of pathogenic organisms and of toxic concentrations of certain chemicals Unfortunately these two criteria cannot be assessed by simple tests For example there is no direct relation between the appearance of a sample of water and its potability A cloudy sample may be safe whereas a clear sample may be both chemically and biologically dangerous In non industrialised areas the presence of pathogenic organisms is an infimtely more freq
97. get organ by the respiratory system but are not necessarily respiratory toxins Petrolium products Action both toxic and suffocating Pyrethrum Action neuro muscular toxin Alkaloids Action gt neuro muscular toxin 49 1 Jo supa 1 sul 1041409 109 gt TII HI Vector control Technical briefs Formulations Technical product Active ingredient n its purest commercial form Used almost exclusively for ultra low volume ULV application Powder and granules Active ingredient 0 5 to 10 with inert carr er talc gypsum etc Powder is used for the control of lice and fleas Granules allow better penetration of dense vegetat on Wettable powder Active ingredient 20 to 80 wetting agent inert carrier Used for preparation of aqueous solutions Concentrated suspension Active ingredient in a fine powder 10 to 50 wetting agent water Used for preparing aqueous suspensions Solution Active ingredient dissolved in a solvent As most insecticides are insoluble in water the solvent is most commonly gas oil kerosene or even acetone or xylene Emulsifiable concentrate Active ingredient 25 or more solvent emulsifying agent oil This formulation allows dilution in water later Emulsion Emulsifiable concentrate water Slow release formulations Slow dissolving capsules granules briquettes etc w
98. give definition as clear as possible of the technical terms used in the guide or those which are used every day in this field Criticisms and comments are invited from users of this guide They are important to ensure that it is developed to be as appropriate as possible to the realities and needs of the field Please send your comments to M decins Sans Fronti res Service m dical 8 rue Saint Sabin 75544 Paris Cedex 11 France Tel 33 1 40 21 29 29 214360 Fax 33 1 48 06 68 68 Contents Introduction Site Planning page 9 Water in camps of displaced people Needs page I 3 Water related health risks pagel 5 Water supply page I 9 Assessments of water quality page 1 13 Should the water be treated page I 16 Simple water treatment technique page 1 18 Technical briefs page 1 23 B Sanitation Excreta disposal page II 3 Removal and treatment of wastewater page II 8 Collection and disposal of refuse page 12 Technical briefs page II 15 Vector control Introduction page III 3 The principal vectors biology and control measures page III 4 Precautions for use and storage of pesticides page III 16 Spraying equipment page III 19 Technical briefs page 21 4 English French Spanish glossary conversion tables and estimations Engl sh French Sparush glossary page IV 3 Conversion tables page 10 Materials and labour estimations page IV 11 BH Bibliography page V 3 Site Planning Site Pla
99. h Gravel Plug at the end of dram Straw or plastic sheehng Distribution box 1 2 3 4 5 6 7 8 Important Dispersal systems using simple or multiple trenches are an alternative to soakaway pits for less permeable soils where there are large quantities of effluent in the case of a hugh water table or where there are rocky layers near the surface To estimate the dimensions of the trench evaluate the infiltration capacity of the soil and allow for a possible increase in the amount of wastewater to be disposed of For a system with several trenches distnbution box is installed at the beginnung of the drains to ensure that the effluent flow is well divided The box should have an inspection cover and may be designed l ke grease trap see techrucal brief Grease trap The straw or plastic sheet over the gravel bed prevents the entry of soil which would block the system The bottom of the infiltration trench should be at least Im above the level of the water table during its highest penod and 1m above any umpermeable layer Sanitation Technical briefs SOIL PERMEABILITY Porcolatlon test Cross section Bo 150mm View from above AFPROXIMATIVE ESTIMATION OF INFILTRATION RATE ACCORDING TO SOIL NATURE Soil nature Infiltrationrate litre m2 day Sandy soil earth soil 30 Porous limestone soil 20 Porous clayey limestone soil Compact limestone soil 10 Compact dayey limestone soll
100. h a cover should then be made at the top ofthe tank Otherwise the tank should be fitted with a cover to protect the stored water Once the coats have been apphed it is important to cover the tank with damp jute sacking or plastic sheeting for at least one week for good cunng of the cement This allows the cement to develop its full strength and avoids the risk of cracks appearing 1 33 I Water camps Technical briefs FABRICATING CONCRETE RINGS Outside diameter 1 15 m Inside diameter 1 m TI D a 3 Technical briefs 1 Water camps Fabricating concrete rings Method Concrete rings are needed to line and protect hand dug wells They may have other uses such as malang a spring box raurumter collection tank etc Concrete rings for infiltration at the bottom of a well may be perforated during fabrication or made of porous concrete Porous concrete rings are preferred for use in decomposed rock sand or gravel Concrete rings used for the main part of a well or for water storage should obvtously not be porous or perforated The internal diameter of the rings should be at least 0 8m so that a person can work mside the ring if Necessary The mould is of steel plate at least 3mm thick reinforced with angle steel It 1s composed of two parts the internal and external rings Each of these parts is made of three sections which bolt together The mould 15 generally 1m high less 1f
101. he supply can meet users needs Never ty to make the water rise above the highest point of resurgence as this could produce a back pressure which would make the flow emerge elsewhere The water should be captured on the impermeable layer Be careful not to divert the spring 1n another direction or into another fissure when digging around it Terraang should start at the point where the water comes out of the earth Continue to dig working back up the water bearing layer while ensuring that the water flows away A good spring should have a constant temperature If this Js not the case check above the spring to see 1f the water comes from a surface water source wh ch runs underground The yield of a spring with such a surface source will nse immediately f it ra ns It may be considered that for a reliable spring gt the yield in the rainy season 3 to 5 maximum the yield in the dry season The distribution and overflow pipes should be fitted with a screen e g metal mosquito netting in order to avoid the passage of insects and or large particles 1 29 Water in camps Technical briefs WASHING AREA Section AA Slope 3 4 Section BB Technical briefs I Water in camps Method As is name suggests a washing area should provide a hygiene facility for a population m an emergency situation without creating environmental health risks stagnant water etc It is built close to a water point and its de
102. hecking that an excess of unconsumed chlorine remains in the water residual free chlorine see technical brief Monitoring chlorination EFFECTIVENESS At the doses normally used chlorine destroys all pathogenic viruses and bacteria in water but it is ineffective against protozoan cysts and helminth eggs or larvae pathogens within suspended particles as they are thus not in contact with the chlorine so 1t is advisable to filter water prior to chlorination to remove eggs cysts larvae and suspended particles 1 19 1 Water in camps Sanple water treatment PRACTICAL USE Chlorination 1s a very suitable treatment method for emergency situations e g typhoid or cholera epidemics because it is very effective but it is relatively tr cky to set up and needs constant attention If water bas to be treated which method sbould be used The choice of treatment method will depend on the appearance of the water the supposed degree of pollution or that measured by bacteriological analysis and the technical options See the following table In an emergency chlorination is often the best technique but in the long term slow sand filtration is generally the most appropriate solution However it is always better to use water which does not need treatment 1 20 Treatment Effectiveness Resources needed Operation Cysts Bacteria Viruses Eggs O to Reservoirs with outlet to drain sed
103. hich allow continuous release of larvic de n water The concentration may be expressed as weight per volume for liquid formulations or as weight per weight dry formulations Technical briefs Vector control INTERNATIONAL CODE OF DIFFERENT FORMULATIONS EXTRACT AB AE AL BB BR CB CS DP EC EO EW FG GB GG GR LA MG OF OL PB RB SL SP SU TC UL WP bait as grain aerosol generator other liquids to be used without dilution ba t as a block briquette concentrate for preparation of bait granulated in capsules capsules suspended a liquid to be diluted in water before use dusting powder hquid concentrate to be diluted in water before use emulsion with ready to use emulsion with water ready to use fine granules 0 3 to 2 5mm granulated bait large granules 2 to mm granules ready for use Lacguer micro granules 0 1 to 0 6mm concentrated suspension to be diluted in oil liquid to be diluted in bait n bars bait ready for use liquid formulation to dilute in water powder to d lute in water suspension ready to use for ULV treatment product n its most concentrated commercial form liquid ready to use for ULV treatment wettable powder for dispersion in water Vector control Technical briefs Propoxur Carbamate Commercial names Baygon Blattanex Unden Toxicity per os for rats LD50 9
104. hot water 11 27 Vector control Technical br efs Deltamethrin Pyrethrinoid Commercial names K Othrine Decamethrin NRDC 161 C st n Deas Toxicity rats 1050 135mg kg Mode of action Contact and ingestion Formulation Wettable powder 2 5 Concentrated liquid 25g ltre Method of use Wettable powder One sachet of 33g 6litres of water Concentrated liquid 1 litre 200 litres of water Spray at the rate of 1litre 10m2 For use against Flies cockroaches bait fleas ants mosquitoes etc Cost Wettable powder about 3 US per 33g sachet Quantity to allow 1 sachet per 60m Precautions No specific precautions Technical briefs HI Vector control Malathion organophosphate Commercial name Malathion Toxicity rats LD50 2 100mg kg Mode of action Contact Formulation Concentrated liquid concentration varies with manufacturer Method of use Prepare a 1 Malathion shampoo with a detergent solution Apply 15 to 20ml per person Do not rinse for 24 hours For use against Headlice Cost About 6 US litre Quantity to allow Depends on concentration of initial solution Precautions See page 16 Use a deodorised product 29 Vector control Technical briefs Pyrimiphos methyl organophosphate Commercial name Actellic Toxicity rats LD50 2 018mg
105. i res organiques Mater as org nicas Residues and extracts of living organisms P Permeability Perm abilit Permeabilidad Ability of soil to allow water to infiltrate Pit latrine Latrine fosse simple Letnna s nple Latrine with a single pit dug in the ground pH pH pH Expression of the degree of acidity or alkal n ty of a substance The value of 7 35 is neutral values above this are alkalme values below are acidic Phenol Red Rouge de ph nol Rojo de fenol Chemical compound used to measure pH by colorimetnc comparison be in tablet form Pour flush Latnne siphon Letrina con Latnne in which the slab has a pan and latrme d eaude sif n de agua water trap wluch 15 flushed manually IV Glossary English French Spanish Definition Protozoa Protozoaires Protozoares Group of unicellular microscopic animals certain of which cause disease e g amoeba R Ranwater Eaux pluviales Aguas pluviales Water from atmospheric precipitation which may form a water source Resurgence R surgence Resurgimiento See Emergence Retention time R tention Retenci n Time dur ng which wastewater is held in a tank to undergo treatment eg 1 to 3 days for a septic tank Run off Eaux de rurssellement Aguas escurrimiento Water flowing naturally on the ground surface 5 Sanitary inspection Inspection samtaire Inspecci n sarutana Field observation using criteria to evaluate the environmental hygiene status of a settlement e g refuge
106. ible tube attatched 1 brush to clean ceramic candle 1 gauge to measure thickness of candle Tap filter Filter body with flexible hose and universal rubber tap adaptor Ceramic candle delivered together Important Siphon filter ensure that the flexible tube is firmly attatched to the ceramic candle so that no water is siphoned directly without filtration Gravity filter assemble the candles correctly with their rubber washers to ensure that no water passes without filtraton Katadyn filter change the candle as soon as the measuring gauge passes freely around t see maker s instructions Teams in the field should always drink filtered water because they can never be sure of the quality of local water supplies Never let the candles come into contact with boiling water as there is a risk of cracks formung Maintenance of ceramic candles when the flow becomes too weak brush the candles eg witha toothbrush under clean running water rinse and reassemble The candles are fragile handle them with care The tap filter 15 ideal for washing hands etc n an operating theatre if the hospital has running water careful not to loose the Little rubber rings on the tap adaptor 1 39 1 Water in camps Technical briefs SLOW SAND FILTER LEI TER ANN PREFILTER PREFILTER FILTER Raw water reservoir inflow pipe Technical briefs 1 Water in camps Slow sand filter Method Slow sand fil
107. ight of the fire bars Lay the fire chamber slab and cement the fire bars in place 6 Continue the walls up to the chimney If possible plaster the inside of the fire chamber with a heat resistant puxture 7 Lay the upper slab which acts as a base for the chunney 8 Build the chimney at least 1 5m high be sure to use a plumb line the chimney should be perfectly vertical 9 Fit the fire chamber and refuse loading doors 10 Let the structure cure for 2 to 3 weeks covered in wet jute sack ng or plastic sheeting before using t Key Inputs Brick walls 7 x 14 x 28cm Detailed plans Fire bars 3cm spacings About 300 refractory br cks 7 x 14 x 28cm Door of fire chamber 4 bags of cement _ Sand 270 I tres Door for loading refuse Gravel 125 litres Chimney Refractory plaster mix earth lume or cement Base reinforced concrete 130 x 70 x 8cm 2 metal doors Fire chamber slab reinforeced concrete 15 metal bars 8mm dia 650mm long 70 x 60 x 3cm Reinforcing steel 6mm 18m Top slab remforced concrete 100 x 70 x 7cm Shuttering tumber for the slabs Pay attention to the opening left for the Builder s tools chimney 25 x 45cm About 3 days work for one experienced builder and one Jabourer Important The combustion capaaty of such an ncinerator 15 about 100kg of refuse per hour The incinerator should function with the loading door shut to encourage the draught The same remarks on op
108. iment For small filters sand gravel empty drums 1 Treatment of very slightiy polluted water 2 Pre treatment of turbid water before chlorination Pre treatment of turbid water before chlorination Slow sand 1 Treatment of slightly Not suitable for filtration Gravel polluted water very turbid microbio Reservoirs 2 Pre treatment of very water purification pre fabricated or polluted water before chlorinated chlorination water filters empty oil drums for small filters Should be 1 Treatment of clear Chlorination at the doses ting product water preceded generally used Reservoirs 2 Complementary to by sedimentation If chlorination is sedimentation and filtrauon and or filtration continuous a for slightly turbid or very if water is turbid chlorine doser polluted water yava 121001 dung Sdiuro ut 230M 1 Technical briefs Technical briefs Digging a well Protecting a well Protecting a spring Washing area Ferrocement tank Fabricating concrete rings Choosing a motorpump Ceramic candle filters Slow sand filter Chlorine generating products Monitoring chlorination Water sampling Water storage kit 2 0001 Water storage kit 15 0001 Distribution tapstand kit Motorpump kit 1 24 1 26 1 28 1 34 1 36 1 38 1 40 1 42 44 1 46
109. inated must contain as httle visible suspended material as possible If t is turbid a pretreatment such as sed mentation and or filtration should be done before chlor nation Chlonnahon 15 effective against practically all pathogenic micro organisms n water The only way to be sure of th s effectiveness s to dose the free residual chlorine correctly determuned the chlorine demand may vary over time wi e organic material n the water It is thus Important to measure the free residual chlonne frequently in order 8 Extrapolate the 1 dose to the volume of water to be treated 9 Pour the solution into the reservoir mix well during filling and wait 30 minutes before distributing 1 solution Inputs Several containers of the same known volume buckets jerrycans etc 5ml synnge Measuring equipment comparator and DPD1 tablets Watch to measure the 30 minutes The MSF chlorination kat available through MSF logistics contains all the material needed for chlorination and dosing rotect micro organisme The Tene 0 2 and 5eng l but even 1f the dosage rate 15 ed changes m the amount of Metal consumes chlorine so never prepare strong solutions in metal containers unless they are enamelled Concentrated chlorine products should be kept in dry shaded place and guarded Chlorine 15 dangerous particularly for children When contact with
110. inutes Avoid exceeding 170 C because you risk to damage the instruments Key Electricity Temperature conirol Poupinel Thermometer Metal instrument boxes Heating ume control Indicator tape if available Circulating fan Shelf Electriaty supply 1 2 3 4 5 6 7 8 Important Ensure that umng starts only once the sterilization temperature 160 C or 170 C has been reached If Poupinel adhesive stenlization indicator tape s available do not confuse it with the tape used for autoclave sterilization which is very simular stick small pieces on the outside of the boxes the indicator tape tums brown if the correct temperature and time have been achieved Only sterilize metal instruments without any plastic or rubber parts heat proof glass Pyrex type or vaseline in the poup nel Any other type of matenal will burn Anything which can not be sterilized in the Poupinel may be sterilized m an autoclave see Sterelisation by autoclave This method of stenlizaton consumes a lot of electricity Although there are charcoal or kerosene heated Poupinels available only the electric models are considered reliable 55 Sanitation Technical briefs SANITARY SURVEILLANCE FORM Camp dee gt Setlon nevm 2 Date a Population Number of shelters mu os menu b Number of families d Number of persons shelter e
111. itation programme The analysis of ls results should reveal both technical and operational problems in such a as to highlight trends and promote immediate action and if necessary a re onentation of the programme by revision of the objectives and resources deployed Sanitary surveillance 1s done above all through field observation or sanitary inspection and by establishing indicators which allow specific objectives set for the programme to be quantified e g quantity of water per person per day The frequency of surveillance activities depends firstly on the situation and the results obtained Monthly inspections should be considered a m n mum When there are particular problems a sudden influx of people the rainy season epidemucs evaluation of a programme s impact this frequency is increased To carry out the sanitary surveillance correctly a standardized form is used to collect essental information see opposite page This form should be adapted to each situation and should always be designed for use and interpretation by local staff who should eventually be able to carry out this surveillance themselves Sanitary inspections develop field knowledge an understanding of how well the water and sarutation nstallahons function and are maintamed and of the habits and practices of the population and general hygiene conditions It is preferable to carry out inspections accompanied by local staff responsible for the area
112. itch Crossing point of ditch Lowest comer towards soakaway pit Lorry or cart for transporting refuse Lorry bringing refuse Trained personnel permanently at the hp Excavated earth used progressively for Shovels for covering refuse operation covering Boots and gloves for personnel Refuse Broom and 0 05 chlonne solution or lysol for Layer of backfilled earth dany cleaning of the cart or lorry Important This technique needs a lot of land and sophusticated equipment for its implementation which entail heavy costs Important the bottom of the trenches must be more than 1 5m from the water table to avoid pollution by leachates The compulsory distance from dwellings demands the use of a lorry or cart The staff should be trained for their task and should wear protective clothes washing fac l hes water and soap at least should be available at the site If the 15 designed to have a lifespan of more than 6 months it 1s possible when the end 1s reached to redig the start of the first trench filled to reopen the tp Otherwise it 15 necessary to open a second bp during the hme t takes for the first one to stabilize The fence 1s essenhal to avoid scavenging and accidents at the tip 1 33 Sanitation Technical briefs 4e cw dn CERE we e Technical briefs H Sanitation Method The dustlins may be used along paths and roads a refugee camp or in
113. izaci n Elumunation of all mucroorganisms from water or from a surface virus bacteria and microscopic fungi Stormwater Eaux pluviales Aguas pluviales Rainwater running on the ground rain run off surface collected and disposed of separately from wastewater Stock solution Solution m re Soluci n madre Concentrated chlorine solution generally 1 used for chlorinating a known volume of water Strainer Cr pine Pichancha Filter at the bottom of a motorpump suction pipe to keep back large impurities Often used with a non return foot valve Submersible pump Pompe immerg e Bomba submergida Pump with the pumping part under the water delivery only Subsurface Epandage Esparcimiento Treatment and el mination of dranage souterrain subterr neo wastewater by infiltration into the subsoil Sullage grey water Eaux m nag res Aguas usadas Wastewater from kitchens bathrooms Surface pump Pompe de surface Bomba de superficie Handpump or motorpump with the pumping part at the surface suction head limited to 7m Surface water Eau de surface Agua superficial Water from precipitation making streams rivers lakes ponds etc Suspended Mati res en Matenas en Organic and mineral particles solids suspension suspenci n suspended in water T Trench latrines Feuill es Letrinas Shallow trenches usedfor defecation m atrincheradas certain emergency situations Turbid water Eau turbide Agua hirbida Water conta ning fine particles in
114. kg Mode of action Contact Formulation Emulsifiable concentrate Wettable powder Dusting powder Method of use Flies Actellic 50 EC 1 litre in 40 litres of water Actellic 25 PM 1kg in 20 litres of water Powder at 2 ready for use Bait 1g m of powder at 2 mixed with sugar half and half For use against Adulticide with immediate or residual effect on flies mosquitoes lice fleas etc Cost Concentrate at 5096 about 14 US litre Powder 1 about 4 US kg powder 2 about 5 US kg Quantity to allow Depends on formulation used Precautions See page M 15 Technical briefs IL Vector control Temephos organophosphate Commercial name Abate Toxicity rats LD50 8 600mg kg Mode of action Contact Formulation 2 solution Emulsifiable concentrate Granules Briguettes Method of use Reservoir of drinking water 56 to 112g of active ingredient hectare for 2 to 4 weeks River 1g nv of flowing water for 10 minutes For use against Mosquito larvae in dr nking water Simulium blackfly larvae Cost 2 solution about 7 US kg Ouantity to allow Depends on the formulation and the area to be treated Example 2 solution 3ml 3m of drinking water Precautions No specific precautions 31 Vector control Technical briefs Repellents Repellents are chemical products used on cloth or
115. l irngation is also practised The water 1s distributed in a system of channels between rows of plants and infiltrates vertically and horizontally e g for potatoes beans bananas paw paws etc Construction Choose a site for the garden about 15m from the water point Dig a channel or drain to collect the wastewater Prepare the garden m basins or furrows depending on the crops grown and the space available The passage of water from the channels into the basins may be regulated using sluices or earth Continue the main channel to the end of the garden to dispose of excess water n soakaway pit or infiltration trench Erect a fence to keep animals out Inputs Gardening tools Tools and matertals for construction of final disposal system see technical briefs Soakaway put and Infiltration trench Fence local materials Sluices e g short planks Seeds Important In refugee camps where space is limited an irngated garden Is preferable to infiltration disposal systems It provides a nutritional supplement for the refugees and a source of act v ty and possible revenue Water containing detergents may be toxic to some plants Install a grease trap see corresponding bnef if the water comes from the washing area Take local advice on the choice of rr gatlon method and the watering frequency Wash vegetables even root vegetables before cooking and eating 49
116. l leaders etc 3 Collect information geographic climatic demographic socio cultural technical and material 4 Propose alternatives analysis of data and techrucal options 5 Choose a method needs social suitability resources financial material and human geography soils water climate space family or collective systems 6 Implement the system chosen involve the population control the costs plan the construction 7 Use and maintain the system inform educate Take special care with collective Systems 8 Evaluate the system sanitary inspection and monitoring system Calculation of tbe effective volume of a latrine pit The pit latr ne 1s the most common system of excreta control in the world To calculate the effective volume of a pit proceed as follows V NxSxY where V effective volume in m3 N number of users 5 sol ds accumulation rate in m3 person year Y lifetime of latrine in years 6 Excreta d sposal II Sanitation For dry pits use a solids accumulation rate of 0 04m per person per year For wet pits use 0 02m per person per year When calculating the total pit volume a free space of 0 5m at the top of the pit is added to the effective pit volume The volume may also be increased by 30 to 50 1f bulky anal cleansing material 15 used e g stones maize cobs etc The suggested design life of a non emptyable simple pit latrine is 5 to 10 years That of an emptyable l
117. l pipe ve 2 people for assembly and installation 1 tee 2 crosses 1 elbow for connections Bladder tank for supply 6 Taflo Talbot taps 2 Heliflex pipe Steel braces 4 short stakes or 4 long stakes for anchorage 2 t 4 reducing tee fi ucing tee for connechng the 1 large hammer or mallet for driving in the Stopper and chain DN50 connection fitting stakes 15m or 2m bladder tank Enough stones to complete the dramage works 2 outlet valve and tee 2 pipe Fence posts and ropes Paved and drained area Distribution tapstands Drain for wastewater 1 pipe wrench 1 connection spanner Important It 1s important to arrange the area around the taptstands well access drainage to avord mud and stagnant water If several tapstands are to be installed at the same place separate them enough to avoid pushing and shoving at busy times The 15m tank has 2 outlet valves so it is possible to install a tapstand at each end to have two distinct distribution points The Taflo self closing taps are designed to work at very low pressures A How of about 101 per mun at each tap may be obtained with a fall of between 1 and 1 5m between the tank and the taps In any case this difference in height Is recommended as minimum To have a good flow to all taps do not place more than 2 tapstands n series Check from time to time that the taps close properly Solid particles in the water or object
118. lat stone 10 where the water flows onto the filter so it will not to disturb the Schmutzdecke by its turbulence 10 Insert and fix the pipework outlet and overflow Important the outlet pipe must rise above the level of the top of the sand so that the filter surface is always under water even if the water supply 15 cut Key Inputs 1 Raw water mlet valve Two 2001 drums 2 Perforated plate holes about 2mm dia every Metal saw hammer cold chisel tape measure 5cm Dnil and bits 3 Coarse sand 1 2mm dia Round and half round files 4 Large stone e g cobbles Pipe PVC or galvanised 1 2 or 3 4 5 Plug holes with plugs Pipe threader for galvanised pipe or solvent 6 Prefilter overflow towards filter and PVC glue 7 Eine sand 0 2 0 5mm dia Teflon tape or mast c and tow for making joints ravi Elbows and nipples for fian 9 Perforated pipe for collecting filtered water Anticorrosion pur pen aes 10 Flat stone Paintbrush and thinners 11 Outlet valve Cobbles stones 12 Outlet pipe to distribution Coarse sand about 1mm dia about 0 12m 13 Overflow Fine sand 0 2 0 5mm dis about 0 3m A Minimum water level in filter Gravel about 0 03m B Maximum water level in filter Important The filter sand should be of un form size Steve it using mosquito netting for instance Before the first use fill the prefilter and the filter with a solution of 100mg 1 chlonne 10ml of
119. lth centres refuse is collected in separate containers some dustbins are available for ordinary refuse and others clearly marked are used only for medical waste Collection Collection should be done at least once per week to avoid the hatching of flies and odour problems In practise the use of a whole chain of different resources need to be optimised but a daily collection is the 1deal The collection of the contents of dustbins without forgetting the surroundings may be done with vehicles But it may be more reliable logistically to use hand carts or animal carts Moreover it is difficult in emergency situations to commit a vehicle exclusively to this task The collection should be organised establ shment of circuits constitution of teams allocation of a circuit to each team After its introduction the collection system should be supervised and evaluated periodically Is the circuit appropriate Are the resources enough 1 13 IL Sanitation Collection and disposal of refuse These two steps of storage and collection require the co operahon of the population which should be involved regularly once or twice per month n a general dean up of the camp Disposal Three techniques are used burying incineration composting BURIAL Burial is done n trenches Controlled tipp ng see brief Controlled t p is only used where there is sufficient space and access to mechanical equip
120. ly in order to spot and deal with blockages Treatment Wastewater treatment techniques mostly need specialised skills and technologies For this reason these sophisticated techniques will not be studied in this guide Information will be limited to infiltration systems and the basic principles of waste stabilization ponds INFILTRATION Infiltration uses the natural capac ty of the soil to fix particles present in water by filtration and to purify the water by a process of biological decomposition capable of destroy ng micro organisms and chemical pollution This natural capacity is always extremely vanable depending on the soil type mature organic rich soil 15 host to intense biological activity favouring purification but 1t blocks rapidly and so has a reduced infiltration potential Conversely a sandy 501 may have an infiltrahon rate which 15 too rapid and which does not allow sufficient time for punfication if the water table is too close to the surface For the same reasons a fissured rock would have only a small pur fy ng capacity practice the two following parameters should be studied The slope of the ground a slope too steep may encourage water to reappear and so contaminate the ground The infiltration rate determined by percolation tests with clean water see technical brief Soil permeability 10 Removal and treatment of wastewater Sanitation The principle of infiltr
121. ment Access to the site should be restricted a fence If good drainage is not ensured there is great risk of the trenches turning into sickening quagmires The siting of the trenches should follow the same rules as for siting latines as the risk of polluting the water table 15 the same INCINERATION Medical waste should be incinerated as it is potentially contaminated This method 1s not generally suitable for household wastes as it is costly and may be dangerous when it is done on a large scale atmospheric pollution COMPOSTING Composting is biological decomposition n the presence of air as opposed to anaerobic decomposition which takes place in septic tanks for instance It is a technique which needs special care and which may cause major health risks if not mastered correctly For this reason it should not be used in emergency situations 14 Technical briefs II Sanitation Technical briefs Trench latrine 16 Simple pit latrine II 18 Ventilated improved pit latrine 11 20 Twin pit latrine 22 Latrine slab 24 Pour flush latrine 26 Septic tank 28 Refuse 30 Controlled tip 32 Dustbin 34 Temporary incinerator 36 Permanent incinerator H 38 Soakaway pit 40 Infiltration trench IT 42 Soil permeability II 44 Grease trap I 46 Irrigated garden II 48 Evapotranspiration area IT 50 Sterilization by autoclave 52 Sterilization by hot aire 1 54 Sanitary surveillanc
122. mitted by direct and domestic contaminahon hands water food and objects contaminated by excreta The pathogens may be viruses bacteria protozoa and certain helminths The list of feco orally transmitted diseases 15 long and includes diarrhoeas typhoid fever cholera amoebic dysentery giardia hepatitis A etc Control measures providing toilets improvement of water supply improvement of shelter conditions improvement of hygiene practices 2 Helminths worms transmitted by soil Helminth eggs have a latent period or period between the moment they are excreted and the moment they become potentially infecting The transm ssion of these geohelminths takes place through the contamination of soil or crops It mainly concerns ascaris tr chur s ankylostoma and strongyloides Infection by these helminths is very frequent and prevalences may be greater than 90 in certain populations Control measures general excreta control and or treatment of excreta before use for fertilizing crops Sanitation Excreta d sposal 3 Beef and pork tapeworms t nia Cattle and pigs are intermediate hosts of t nia The transmission cycle involves the contamination of soil and forage by human excreta then the ingestion of undercooked meat by humans Control measures excreta disposal and or treatment before use as a fertilizer inspection and thorough cooking of meat 4 Water based helminths
123. nciple SLOW SAND FILTRATION Under certain conditions in passing water through a bed of sand particularly effective filtration is achieved by biological purification in addition to the mechanical action of the filter For this to occur the filtration must be relatively slow A deposit 1s formed at the surface and in the top few centimetres of sand in which breeds a whole range of bacteria and microscopic plants forming a skin called the Schmutzdecke biological membrane or bacterial film which works both biologically and mechanically It acts as a very fine filter which retains or kills most pathogenic organisms t eliminates eggs cysts nearly all pathogenic bacteria and proportion of viruses Slow sand filtration is the only procedure which achieves such an improvement of water quality in a single operation A slow sand filter can operate for weeks or even months without maintenance which consists of the removing of a thin layer of sand when the filtration rate becomes too low 1 18 Simple water treatment I Water camps practice At the collective scale the construction of this type of filter needs the mput of specialist and then the maintenance is relatively simple smaller scale for example feeding centre small filter may be made with local materials Whatever the size of the filter the operating pr nciple remains the same Important The bacterial layer 15 fragile and cert
124. necessary action in case of poisoning Always have a shower system available bucket of water and soap 16 Precautions for use and storage of insecticides HI Vector control Criteria for selecting staff Avo d people with the following risk conditions when select ng staff to make up a treatment team Pregnancy Alcoholism chronic or otherwise History of liver or nerve disorders Heavy smoking Allergies or skin diseases More subjective criteria are also important professional integrity met culous work neatness and tidiness Before starting to make up and train a team find out if suitable people are already available in the region although a mosquito control team is not trained to manage a programme to control lice or do aerial spray ng Precautions to take during transport and storage TRANSPORT One of the most frequent risks of poisoning by insecticides is from leakages of concentrated toxic products during transport International legislahon forbids the transport of concentrated products with foodstuffs Serious accidents have already occurred through not respecting this basic rule For land transport always repack drums with leaks or with worn corners at the base Put straw or other absorbant material in the bottom of the vehicle This should be burned on arrival Load with care pack the drums closely together and tie them down to avoid them jumping up and down
125. needs free water e g infusion liquids Its maamum weight 1s 20g and its length 20cm For two animals of the same size the head and feet are larger in the young rat Nests are built in any place where there is an accumulation of matenal for making the small shelter which the mouse needs making control difficult specially as the adult s sphere of activity is never more than a few meters Control methods ENVIRONMENTAL HYGIENE As for any other vectors this means making the environment unsuitable for rodents working on two fronts Food packaging of stored food disposal of refuse Reproduction eliminatation of likely sites refuse tips waste packaging scrub PROTECTION AGAINST RODENTS The aim 1s to prevent access by rodents to important or vulnerable areas food stores infusion liquids etc Block or protect all openings greater than 6mm with cement or metal netting Imm wire mesh less than 6mm dia Fit discs on cables joirung roofs Paint a smooth band on walls at Im from the ground to prevent passage on rough vertical surfaces Fix galvanized sheet 1mm at the bottom of doors and on the skirtings Stores are always places where people come in and out and where doors are often left open It is therefore useful in addition to the above mentioned measures to organise stores according to the following points Repair all broken packages Leave a passage 1m between wall
126. nical brief Chlorme generat ng products per m3 of water mix and leave the well dosed for 12 hours 4 After this pump out the water until there remains just a fant smell of chlorine I Water in camps 1 27 I Water in camps Technical briefs PROTECTING A SPRING Side section view from above 5 1 28 Technical briefs 1 Water camps Protecting a spring Method A spring should be captured and protected such a way as to maximise the quantity and quality of water supplied If the spring serves few people the spring box acts as a storage reservoir before distribution If the spring serves many peole the spring box is connected to a larger reservoir If the spring box 15 used for storage its capacity should be at least equivalent to a 12 hours period demand Construction Dig out and clean the area around the spring to uncover all resurgences and so obtain the maamum yield Calculate the quantties of materials needed concrete stone bricks etc according to the size of the spnng box and the local means of construction Construct the spring box according to the plan Its base should be on the impermeable layer 1 Build the back wall 4 of stone without mortar and fill the space between the wall and the earth with gravel 3 Cover with a layer of compacted clay 10 to prevent infiltration from the surface Backfill the upper part with soil and dig a drainage ditch about 10m above the s
127. nning large influx of people to site demands the rapid installation of infrastructures which meet the priority needs of the population The health status of refugees depends directly on the organizational capacity of those responsible for their protection and assistance Site planning may be done either for an existing camp where refugees nearly always arrive before aid teams or for a permanent planned site where the initial settlement takes place in a transit camp It 16 essential to plan the site with a long term view there have been Palestinian refugee camps in the Middle East since 1947 Choice of site Available sites are rarely occupied for no reason and the ideal site often remains a dream However certain criteria must still be considered WATER On site water sources available all the year round and in sufficient quantity for the projected population Flood areas must be avoided ACCESS Access should be possible at all times of the year particularly for lorries TERRAIN The land should be gently sloping for natural drainage Soil should preferably be sandy avoid black cotton soil which turns to sticky mud after the lightest of rains Silt creates dust problems when dry The soil type determines which sanitation and construction techniques may be used ENVIRONMENTAL HEALTH RISKS Avoid areas with risks of malaria bilharzia shistosomiasis sleeping sickness trypanosomiasis
128. nst mosquutoes eggs and larvae Fenthion used against mosquito larvae in urban areas and in stock raising areas Temephos almost no toxicity used against larvae in drinking water Problems of resistance Chlopynpos urban larvicide Dichlorvos against domestic arthropods high toxicity and vapour pressure Chlophoxm mosquito larvicide Pyrmuphos methyl skin contact dangerous used by spraying aqueous dilution widely used in public health work CARBAMATES ANTICHOLINESTERASICS Propoxur domestic insecticide low toxiaty Carbaryl problems of resistance PYRETHRIN PYRETHRINOIDS Decamethrin Deltamethrin K Othrine low toxicity irritant to mucosa Effective alduticide almost universally used but expensive Permethrin ditto DIGESTIVE POISONS Action must be ingested by the insect are absorbed by the digestive system ORGANIC COMPOUNDS Action neuro muscular toxins most acting simultaneously as digestive contact poisons some also as fumigants ORGANOPHOSPHATES ton Action block nerve impulse transmission by inhibiting choline sterase production Action go through the external linings of the nsect s body CARBAMATES Action analogous to that of OP compounds ORGANIC Action neuro muscular toxins Action penetrate the insect s body and are carried to the tar
129. o transport It is often more economical therefore to use locally available construction materials planks corrugated iron sheets etc While more durable dwellings are being built plastic sheeting may be used stretched over ropes for temporary shelters Roads and direction signs The road system within the camp should be organized bearing in mind the drainage system so as to preserve the condition of the roads the drainage system can also be installed along the sides of the roads Direction signs are also important they should enable the easy identification of zones of different activities and of each residential area for visitors as well as residents This will be particulariy helpful for home visiting by medical teams and for easy location of any family Direction signs should be understandable for everybody use drawings not everybody knows how to read and the local and international languages For large camps a detailed plan placed at the entrance may be necessary Energy Energy is needed essentially for cooking food Wood is the most common energy source used but it may be logistically difficult to supply and involves politico ecological problems because of deforestation It is thus important to promote energy saving by the choice of fireplace type and possibly by the use of collective kitchens without forgetting the social and hygiene disadvantages of this option 11 Site Planning Ligbting Electrici
130. of 60 minutes The soil may be considered as having an infiltration rate sufficient for a dispersal system if the level n each hole falls by at least 150mm during this 60 minute period Key Percolation test Permeable soil proposed for a dispersal Toperator system 1 hand auger or 1 pick and shovel Test holes diameter 150mm depth 300mm 1 watch or stopwatch Test hole filled with 300mm of water to measure the infiltration rate 1 tape measure Important The percolation test 15 done with clean water so does not allow for the clogging effect of the discharge of effluents carrying solids It has been found that the infiltrahon rate for different soil types s more or less the same once the soil surface s partially dogged The infiltration rate is thus usually found to be between 10 and 301 m day For safety t is better to work the basis of 101 m day for the nfiltraton of effluents and 201 m for clean water e g from a water point The following formula is used to calculate the length of trench needed see also the example opposite Volume of effluent to be nfiltrated litre da Effective infiltranon surface square metres rn Ed Infiltration rate of soil litre per square metre per day Effective in amp ltration surface square metres Length of trench n metres 2 x depth of trench metres Sanitation Technical briefs GREASE TRAP
131. of appearance of resistant strains which render this option costly and neffective In practice In the case of massive infestation by larvae of a defecation trench or latrines used engine oil d esel or kerosene is used to spread an impermeable layer which asphyxiates the larvae but take care of the risks of polluting the water table Ashes or earth may be added to latrines pits after each defecat on or at least every morning and night to reduce the contact between flies and excreta In the case of an epidemic when the presence of flies creates a risk of increased spread of the pathogen and when an operating theatre or treatment room must be protected the use of larvicides and alduticides may be cons dered but always in tandem with environmental hygiene measures Destruction of larvae Spraying of larval sites with an emulsionor a suspension until the surface is completely wetted Destruction of adults Treatment with a residual effect should be done on the surfaces where flies land at night as it 15 here that there is the longest contact time These places may differ according to the species and the climate In general they are external surfaces of building 1n hot countries trees fences dustbins animal shelters etc The insecticide 15 applied an emulsion or a suspension Malath on 5 solution 1 to 2g of active product m or deltamethrin see tecnical brief are the most suitable To give a permanent
132. on Unpack the two tapstands from the box and identify the various parts frame taps nuts and bolts etc Unfold the legs and assemble the frame with the 4 steel braces Use the bolts and the Nylostop MIO nuts with the 10mm spanner in the kat Secure the reducing tee with its vertical pipe for incoming water Use teflon tape PTFE on the thread before screwing on the elbow to ensure a watertight joint Tighten the nuts the pipe to the frame with the 13mm spanner supplied Wind teflon tape onto the threaded ends of the pipes on the tapstand Attatch the 6 taps hghten them well use a wrench supplied in the water supply tool kit Make sure all 6 taps are vertically aligned Choose the site to install the tapstand s the site should be well drained for rainwater and wastewater and accessible for users Position the tapstand s Fix them to the ground using the short stakes in hard earth and the long stakes in soft earth Connect the tapstand s to the tank using 2 Heliflex pipe Tighten the DN50 connections well using the spanner Bury the pipe if possible To connect 2 tapstands in series undo the stopper from the reducing tee on the first tapstand and attatch one end of a 2 Heliflex pipe Connect the other end to the reducing tee of the second tapstand Pave the area with stones and dig a drain for wastewater Pat into service Key Inputs Frame and bolted legs angle steel Galvanised stee
133. on the skin for protection against insects Products used DEET or d ethyltoluam de Dibutyl phtalate Dimethyl phtalate Formulations Lotion The active ingredient is dissolved in an organic solvent This formulation may be used on the skin or on cloth Only natural fibres or nylon have no risk of reaction with the solvent Cream The active ingredient is incorporated a cream An attractive effect has sometimes been noted during the first minutes For thus reason creams are not effective until after 30 minutes Dose The normal dose 15 20g of active ingredient per m cloth mosquito net etc 7g of act ve ingredient per person Effectiveness This varies according to the species concerned It may be assumed that 100 protection lasts not more than two hours whatever the product and that it is about 80 after 5 hours Precautions These products conform to the standards of the cosmetics industry and do not pose any particular risks for the skin Only benzyl benzoate and dibutyl phtalate have a repellent action in a very humid atmosphere Other repellants should be applied on a dry surface this application should be renewed if the surface has got wet rain excessive sweating etc 32 Technical briefs Vector control Impregnation of mosquito nets The use of mosquito nets impregnated with insecticide gives individual protection against nocturnal insects in houses
134. or more than 90 days per year Storage store chlorine products in airtight non metallic containers sheltered from heat light and humidity chlorinated hme and all forms of sodium hypochlonte are unstable and do not store well calaum hypochlonte stores better loss of achve chlorine 1s about 2 per year but NaDCC is by far the most stable chlorme generaung product PREPARATION OF A 1 SOLUTION For chlor nat ng drinking water a stock solution of 1 chlorine is used whichever chlor ne generating product is used Product at n chlorine gt 1 solution use Starting with a product at n active chlorine a 1 solution of chlorme contains 10g of chlorine per litre so t needs 10 x 100 n grammes of product per litre of solution Example calcium hypochlonte at 70 active chlorine 10 x 100 70 15g 1 of solution Calaum hypochlorite at 70 15g l 1 level Let the deposit and settle and use achve chlonne soupspoon litre only the supernatant Chlorinated lime at 30 33g l 2 level act ve chlor ne soupspoons litre Sodium hypochlorite at 200ml litre Only if manufactured very recently suitable 5 active chlorine lt 3 months and only 1f stored away from heat Sodium hypochlonte con centrate at 15 active 75ml htre chlonne Sodium dichloro 1socyanu rate NaDCC at 1 5g active 7 tablets Ensure that the excipients in the chlonne per tablet tablets are non toxic The 1 stock solution should be kept in an a
135. or this purpose D DPD1 DPDI DFDi Diethyl p phenyl ne d am ne Used in tablet form with a colorimetric comparator to measure free residual chlonne Defecation D f cation Defecaci n Passage of waste matter from the bowels Detergent D tergent Detergente Compound used cleaning e g wash ng clothes often found n polluting wastewater Disinfect D sinfecter Desinfectar To kall a large proportion of micro organisms present in water or on a surface Distribution box Bo te de distribution distribuidora Construction for collecting effluent from a septic tank and distributing it equally among drains in a multiple trench infiltrabon system Domestic refuse D chets m nagers Basuras Putrescible or non putrescible solid waste waste material from household activities Dran Drain Tubo de desague Underground pipe with pierced holes ar slots to a allow the passage and infiltration of water Drainage Drainage Drenaje Removal of water by d tches or pipes E Range and average of size of grams of Effective grain s ze Granulom tne Granulom trica or other material used as a filter material Partally or totally treated waste water Effluent Effluent Effluente comung from a treatment unit and going to secondary treatment or disposal IV 5 IV Glossary English French Spanish Definition Emergence eye Resurgence Resurgimlento Place where spring water appears at the surface Evapotranspiration E
136. ot using electriaty The sterilization time 15 the same whatever heating method 15 used Only start counting the stenlizaton bme from the moment the temperature pressure is reached after air bleeding If adhesive indicator tape 1s available do not confuse this with the tape used for hot air stenlizahon stick small pieces to the outside of the boxes the indicator tape turns brown if the sterilization time and temperature have been achieved NEVER operate the autoclave without water the heating elements will be destroyed NEVER try to open the autoclave before the end of the cycle 1 53 II Sanitation Technical briefs STERELISATION BY HOT AIR Technical briefs Sanitation Ste Method The Poupinel oven 15 used for sterilvang medical and surgical equipment unih hot ar Place the hermetically sealed boxes of instruments in the Poupinel loosely packed and not stacked so that aur can circulate between them Set the thermostat 3 at the desired temperature see below Set the timer 5 at the desired time see below Close the door Monitor the temperature 4 Timing starts only when the thermometer shows the sterilizaton temperature is reached Adjust the setting of the timer at that moment Times temperatures There is a choice of 2 stenllzation protocols depending on the type of equipment and the degree of urgency Either 160 C for 120 minutes Or 170 C for 60 m
137. plastic bag with their fleas Chemical control will only be effective if t is complemented by environmental hygiene and if both efforts cover the whole area concerned Periodic inspection should allow renewed control measures before being faced with a new massive infestation MULTIPLE DOSE PRINCIPAL RODENTICIDES USED IN BAITS Chlorophacinone Poison or Dangerous depending on concentration 21 Coumachlore Poison or Dangerous depending on concentration 21 Coumaf ne Depending on Warfarine concentration 21 Brown rat 0 005 domestic 60cc of commer mouse cial product field mouse 0 25 0 0075 Brown rat black rat domestic mouse Brown rat black rat domestic mouse Domestic rodents resisting to classical ant coagulants NB all these products may be used in poison trails 1 powder in a line 50 cm long and 2mm wide HI Vector control Precautions for use and storage of insecticides Precautions for use and storage of insecticides Precautions to be taken by the operator Before use the operator must be sure of the nature of the product and familiar with the manufacturer s specifications In case of any doubt about the origin of this product its storage conditions or if the label is missing a concentrated insecticide should never be used Check the spray ng equipment Pressured equipment should always be operated first with water to trace any leaks often a cause of
138. ple of water which was filtered Note When incubating at 37 C all the coliforms develop so the count 1s of total coliforms There are kits available for field analysis for example the Del Agua Oxfam kit or the Milliflex k t from Millipore composed of portable filtration and incubation systems However these kits are expensive and require good training in their operation and in the reading and interpretation of results How to express the results of analyses Number of coliforms 100ml if it concerns total coliforms Number of faecal coliforms 100ml or sometimes number of E Coli 100ml the two may be interchanged as in human f ces E Col represents more than 90 of faecal coliforms 1 14 Assessment of water quality I Water camps When to do a bacteriological analysis bacteriological analysis is rarely necessary It is generally much more important and useful to do a sanitary inspection the origin of the water protechon of the water point its siting in relation to defecation areas protection of the water during storage and transport etc Such an inspection will often make it possible to see that the water is polluted or has strong chances of being polluted at some time or other Analysis only gives an indication of pollution at the precise moment of sampling and not of the potential risk of pollution Moreover a sanitary inspection may be done by anyone whereas bacteriological analy
139. pring box to divert run off Erect a fence or hedge around the site at a radius of 10m to keep out anumals which could damage or pollute the spring and to erosion of the drainage ditch Fix an overflow pipe at the height of the top of the spring s flow Lay a surface of stone or concrete under the overflow and a drainage channel to avoid erosion and mud around the spring box Install the delivery pipe connected to the distribunon system about 10cm above the bottom of the spring box Key Inputs Impermeable layer Emergence of spring Detailed plan of spring box Gravel backfill 2 masons 2 labourers Stone wall with open joints Mason s tools Drainage channel Construction materials according to local Desludg ng p pe availability quantities calculated from the size of Delivery pipe to distribution system the spring box Overflow Concrete 1 2 3 cement sand gravel Cover with lock Calculate the volume of concrete needed and Layer of clay multiply by 1 5 to obtain the volume of dry mix Soil The volume of a 50kg bag of cement is 0 033m Protechve fence or hedge Run off drainage ditch 1 2 3 4 5 6 7 8 9 o Important The aim of protecting a spring is to increase its useful yield and reliability and to protect 1t from surface pollution It s important at the outset to carry out a sanitary inspection so as to identify the risks of pollution and to do yield tests to be sure that t
140. promotes the movement of to a new host Patients should therefore be disinfected before being admitted to a hospital structure Control measures include Improvement of hygiene and reduction of overcrowding Preventive treatment of clothes blankets etc distributed by immersion spraying or powdenng Active treatment of every body by powdenng treatments 1 week apart Treatment of clothes by damp heat 1 hour at 70 and by dry heat iron ng Only this method ensures the elimination of lice ticks and bacteria but 1t uses a lot of energy It must not be forgotten when treating that dust from clothing etc is contaminating excreta of lice If possible inform people of the danger of crush ng lice between finger nails or teeth risk of spread of borrelia Vector control The principal vectors biology and control methods Equipment Powder blower hand or knapsack Soupspoon still the cheapest and most practical 1 soupspoon 15 g use one at the front and one at the back Powdering tin or pierced bag Bath tub or simple knapsack sprayer for liquid application Informing the population and training operators are two essential parts of a control programme Precautions Powders dust masks and gloves for teams of operators doing treatment Liquids see Precautions for use When treating head lice malathion is the usual choice of insecticide except
141. protection to certain places e g operating theatre dispensary kitchen strips of gauze or cotton impregnated with insecticide may be used length m of ground surface area Renew the impregnation every two months Where there is a concentration of flies a limited area e g in a feeding centre poisoned baits may be used though there is a risk of poisoning of children and poultry These baits should always be placed outside on the windowsill door etc They may be Dried food muxed with a toxic product 1 to 2 The bat is then spread at a rate of 6g 10 mz or A 10 aqueous sugar solution mixed with the toxic product 0 1 to 0 2 which is spread with a watermg can or sprayer Fly traps The principal vectors biology and control methods Vector control Fleas Fleas are blood feeding haematophagic insects with a close relationship with their host Their developmental stages all occur on land The flea is usually a specific parasite but it is capable of changing its host wild domestic rodent man etc in certain arcumstances Biology The development cycle lasts about one month eggs are laid dusty places in houses or in rodents nests The larvae are found in dark places negative photo trohism In the adult stages both sexes are blood feeders Contam nat on of the host may take place through a bite plague or excreta typhus so dust may be highly contam nat ng
142. r Comments on the pH of water pH 7 neutral pH lt 7 acidic gt 7 alkaline or basic Important chlor nation ls less effective 1f the pH is above B In this case the FRC level after the contact time should be double the normal between 0 4 and 1 Omg instead of 0 2 0 5mg for chlonnation to be considered effective Important f chlorine is overdosed the measurement of FRC may give a false negative result Technical briefs I Water n camps Water sampling Method Important the sampling technique differs according to whether it 15 for bacteriological or chemical analysis The results are discussed n the sechon Assessment of water quality 1 13 Chemical analysis Collect at least 2 x 11 in plastic bottles e g mineral water bottles which must be clean and airtight Rinse the bottles 3 mes with the water to be analysed fill them right to the top label them and send them to the analytical laboratory Bacteriological analysis Collect at least 100ml in sterile bottle To sterilize bottles place the cap loosely on each so that steam can c rculate ns de Wrap each bottle n issue paper newspaper or wrapping paper Sterilize n an autoclace for 15 minutes at 121 C a small autoclave like the Prestoclav 15 quite suitable If there is no autoclave the bottles may be sterilized by boiling place each bottle and cap in the water and let 1t boil for
143. r supply san tat on and hygiene Diarrhoeal diseases are mostly caused by poor hygiene dirty water contaminated environment etc and are among the most deadly each year in the world an estimated 5 million children below 5 years old die as a result of the diseases About a quarter of the world s population is nfested with roundworms and or hookworms Lack of hygiene is directly responsible It 1s estimated that about 300 million people in the world suffer from Sch stosomias s The list continues Although these diseases do not kill directly they are responsible for deterioration in the physical condition a loss of strength and in the long term a reduction of the socioeconomic condition of the people affected Using this guide The guide starts with an introduction defining needs in terms of site planning then 15 divided into three main chapters covering the following subjects Water in camps of displaced people supply assessment of quality and treatment methods Sanitation in emergency situations disposal of excreta refuse wastwater and run off Vector control basic control strategies plus technical briefs on the most common products and application equipment At the end of each chapter there are technical briefs describing different techniques commonly used in the field chosen for their simplicity of implementation There is an English French Spanish glossary at the end of the guide to
144. r will not be necessary 1 41 1 Water in camps Technical briefs CHLORINE Chlorine 15 a chemical whose strong oxidising properties are used for disinfection and decontaminahon Other than its gaseous form which 15 mentioned here just for information because it 15 complicated to use chlorine 15 found the form of chlorine generating products Each product is described by tts chlorine content The chlorine content should be labelled the product s packaging and Is expressed either in of chlonne or in chlorometnc degrees chl or in parts per million ppm or mg of active chlorine litre about 0 3 active chlonne Ippm 1015 1 0 0001 active chlonne DIFFERENT PRODUCTS Product Chlonne content Sodium hypochlonte solution 12 chi ne about 4 active chlorine Sodium hypochlorite solution 15 chL 4002 52 rn bO 5 active chlorine Sodium hypochlonte concentrate 48 chl some nern mn AbOUt 15 active chlorine hypochlonte u about 70 active chlorine Chlonnated lime bleaching powder about 30 active chlorine Sodium Dichloro isocyanurate or 0 powder Eee 60 65 active chlorine tablets 2 1 58 active chlorine tab The UK Department of the Environment authonses the use of NaDCC for disinfecting drinking water emergency or temporary situations as long as doses do not exceed 10mg of product per litre and not used f
145. ransp ration area or an rr gated garden see relevent techrucal briefs Fence off the area to protect it from animals Key Inputs Well head Shovel and pick Drainage channel String line and tape measure Wash ng slab sloping towards drainage Spirit level channel to disposal Sand and gravel Drainage channel Cement about 50kg Dranage towards disposal Bncks or stones Stones Trowel float cement muing trough Plastic sheeting jute sacking leaves etc Important In all cases the dimensions of the washing area should be adapted to the habits and the average height of its users The model illustrated here Is suitable for people used to washing clothes in a crouching position If people prefer to wash clothes standing up a raised washing slab table height or an emptyable raised concrete washtub 15 better Dunng the early days of a camp it is possible to make washung areas using only plastic sheeting of the sort used for temporary shelters The ground surface must be carefully prepared removing all sharp objects stones roots etc Drainage channels may be dug and hned with a double thickness of plastic sheeting following the above guidelines for the slope The edges of the plastic should be anchored to the ground with stones covered with well compacted earth This technique only lasts a few days because 1 the plastic sheeting gets damaged very quickly 2 and it will probably be stolen 1 31
146. re that the results of the analysis reflect the quality of the water and are not affected by possible contamunation on the tap during handl ng Always work with clean hands washed with soap Any contam nation by duty hands will d stort the results Never touch inside of the ster l zed bottle or its cap When sampling hold the cap by the outside never put it down unless it is upside down It is better for security and relability to double each sample Mark the following on each sample and keep copy identification number the place and the type of water sampled as accurately as possible the date and time of sampling and dispatch the substance s or orgarusm s to be identified techniques treatment 1f any of the water product and dose water temperature at the ame of sampling if possible Certain chemical tests require special sampling Enquire about these For bacteriological analysis t is often simpler to use field testing kits g DelAgua or M ll pore in fact samples should reach the analytical laboratory within an hour of sampling if they are kept at ambient temperature or within 6 hours 1f they are kept at between 4 and 6 C but not frozen 147 I Water m camps Technical briefs 2 000L WATER STORAGE KIT Earth platform Clean the surface of the platform Lay out the ground Street Lay out the tank Connect outlets Arrange the drainage and lorry access Ralsed
147. refuse from the top Fill the bottom with firewood through the door 6 Light the fire and give it time to take well Monitor the combustion turning over the refuse frequently Once incineration is complete empty the ashes and dispose of them hke domestic refuse refuse pit or controlled tip Key Inputs Top of drum part not cut 1 drum 2001 e g fuel drum Hole cut for chimney 1 cold chisel and 1 hammer Large chamber for refuse 1 metal saw Cut out of cover 1 pair of pincers and wire Metal drum 2001 1 metal plate same thickness as drum same Perforated metal plate height width about 2 3 of drum diameter Perforations in the metal plate for draught Large nail or punch for making perforations Movable cover System to fix the plate in the drum e g angle Chimney 7 steel and nuts and bolts Fire chamber door used to regulate the draught Tin pipe Metal gratmg or heavy mesh to separate the Hea Heavy mesh or refuse from the fire chamber Metal hinges 4 A B C D 1 2 3 4 5 6 7 Important Never over fill with refuse as the draught comes from the fire the pile of refuse should not be too compact Do not empty the inanerator from the top only take out the ashes which fall Clean out the fire chamber freguentiy Do not try to economise on firewood always keep a good fire going to guarantee complete combustion Turn over the
148. rete should not be too wet Instead of compacting vibrate it by hitting the mould with a wooden stick Porous nngs should cure for longer than ordinary ones They are more fragile and should be handled with care When the rings are produced n series for a programme of well protection it is recommended to use a sheltered area for curing and storing the rings A and pulley should be used to lower the rings safely into the well 1 35 Water in camps Technical briefs CHOOSING MOTORPUMP 1 36 Technical brefs I Water m camps Choosing a motorpump Method motorpump ts composed of a pumping mechanism and a driving mechanism electric motor or combustion engme The choice of a motorpump depends on the type of water source and the work to be done The water source A study of the type of water source nver lake well deep or shallow borehole and 1ts situation allows the choice of a surface pump or a submersible pump For a suction height of up to 7 metres any type of surface pump may be used The pump body 15 at the surface it sucks and delivers For greater lifting heights deep wells and boreholes a submersible pump is suitable an electric pump completely immersed delivery only The work to be done The following information Is needed when speafying a pump for a specific use The discharge O expressed in litres per second or cubic metres per hour or the demand in cubic metre
149. reused The use of collective trench latrines may also be an adequate solution for emergency situations see brief Trench latrines If a high water table rock or sandy soil prevent the digging and use of trenches elevated platforms may be built It is also possible to use 200 litres drums partially buried in the ground with an opening at the top or to use concrete slabs which be set on the top of opened drums If augers or drilling equipment are available drilled latrines covered with simple slabs may be installed rapidly Whatever the emergency solution chosen it is important to take steps to ensure that the facilities work well are maintained properly and are used CHRONIC SITUATIONS Different disposal techniques may be used in refugee camps and in emergency situations simple pit latrines VIP latrines pour flush latrines There is no formula to suit all circumstances For each situation some basic questions must be asked the answers should help in the choice of techruque What are the traditional methods and habits concerrung defecation What method of anal cleansing is used What position is used sitting or squatting What are the cultural soaal or religious habits which affect the technique of excreta disposal separation of the sexes of groups or of individuals particular orientation of latrines taboo places the need to be alone the acceptability of emptying a latrine pit etc
150. rmissible concentrations determine the potability of water Chlorine generating product CaO 2CaOCl n powder form containing 30 chlorine Less stable than calaum hypochlonte Reactive element Cl with strong oxidising powers used for the disinfection of water destruction of organic material and bioadal action Product used for disinfecting water containing a proportion of available chlorine which is released or dissolving in water Difference between amount of chlorine added to water and total residual chlorine level after 30 mins chlorine consumed Fraction of chlorine added to water which is not consumed but combined with certain substances with some disinfectant power but less than free residual chlorine IV Glossary English French Spanish Definition Concrete ring Buse Tubo de concreto Short concrete cylinder for supporting and lining the sides of a well to make them impermeable Contact time Temps de contact Tiempo de contacto Penod necessary for the reaction of chlorine with organi matter contained in water more or less 30 minutes Contamunation Contamination Contaminad n Introduction of potenbally pathogenic pollubon mucro organisms or chemical substances presenting health risks into the environment Controlled tipping D charge control e Relleno san tarlo Method of disposal of solid wastes by san tary landfill bunal n successive layers in ground exclusively reserved f
151. rmost ring should extend above ground level Pack gravel between the rings and the sides of the well 2 Place a layer of gravel about 10cm deep at the bottom of the well n order to avoid the resuspension of settled particles 3 Excavate the earth around the well head to a depth of about 30cm to a radius of about 2m Dispose of all the matenal removed and cast a concrete apron surrounded by a drainage channel confined by a low wall about 5cm high at a radius of at least 1 5m around the well head 4 The slope of the apron 1 should fall to a drainage channel leading to a soakaway pit an imgated garden or a cattle dr nk ng trough see corresponding briefs 5 Install a pumping system follow pump manufacturer s instructions 6 Fix a cover either removable or fitted with an inspection hole on which to mount the pump body The pump makes work easier for users but is also useful because it prevents potentally contaminated objects like buckets from falling into the well Key Inputs Possible entry of pollution Cement about 4 bags of 50kg The well Sand about 400kg Water surface The well Gravel about 800kg Concrete rings Reinforang steel about 20m or steel mesh to Concrete apron reinforce the apron optional Dramage channel Bricks or large stones for the base of the apron Channel to soakaway pit enough to fill underneath the apron Soakaway prt Concrete rings inside diameter about Im height Pum about 80
152. round and inside the latr ne The slab and surround ngs should be deaned every day If possible provide lighting for use at might Never put disinfectants chlorine products lysol etc in the p t this only serves to inhibit the natural decomposition of faeca material The only situation in which it 15 recommended to pour disinfectants into a latnne pit 15 during a cholera epidemic On the other hand it ss recommended that fire ashes are put into the pit after each use This gives perceptible reduction of odours and accelerates decomposition When the pit is nearly full 50cm from the surface demolish 1t or move the superstructure and slab to a neighbouring place and fill the pit with soil Do not dig this place again for at least two years Important allow for the spare 50cm of depth in the calculation of pit size It is not part of the effective pit volume Alternative method f the subsoll is very rocky or the water table is very high and 1t 15 not possible to leave 1 5m between the bottom of the pit and the groundwater level the pit may be partially dug in a very well compacted earth mound In thus case the above ground part should be l ned with bricks or stones Improvements ventilated improved pit VIP latr ne twin pit latrine see corresponding technical briefs Sanitation Technical briefs SSS Selm A r flow 20 Technical briefs Sanitahon Ventilated improved pi
153. s Less than 10 fecal coliforms 100m1 Water may be consumed as it 1s 10 to 100 fecal coliforms 100ml Water should be treated 1f possible but may possibly be consumed as t is 100 to 1 000 fecal coliforms 100ml Water must be treated by flocculation and sedimentation if necessary then slow sand filtration or chlorination More than 1 000 faecal Water is heavily polluted and should be coliforms 100ml rejected or treated very thoroughly Notes In schistosomiasis endemic zones surface water should be stored for two days before use in any case In dracunculiasis Guinea worm endemic zones water should be filtered in any case These guideline values should be interpreted according to the number of people supplied from the particular water source the higher the number the better the quality of the water should be considering the possible extent of a water borne epidemic the general level of hygiene in the camp It is useless to focus on water quality if all the other faeco oral transmission routes are open for example if excreta is scattered everywhere the threat of epidemics of cholera typhoid or shigella if there is a risk of such epidemics all faecally contaminated water or in any case water with more than 10 faecal coliforms 100ml should be rejected or treated if possible If no analysis is done then the same applies to all surface water and to groundwater which is not properly protecte
154. s inserted by users may obstruct or prevent closure 1 53 Water in camps Technical briefs MOTORPUMP KIT PERFORMANCE CURVES Head In metre mk a o a 5 810 15 20 25 30 D bit Petrole Diesel Technical briefs 1 Water in camps Motorpump kit Method The diesel and petrol motorpump lats are packages designed for providing water emergency situations They permit water fo be pumped from water source well river etc a water tanker or a reservar Installation Choose the pumping site t should be easily accessible n all seasons and not liable to flooding particularly where the pump is to be used for filling water tankers Prepare the site so as to install the pump as close to the source as possible to reduce the suction head Lay the suction pipe on a rising slope avoid dips making sure the connections are well hghtened An air leak through the connections could mean losing the primung of the pump The total suction head should be limited to 7m Fit the strainer and footvalve at the lower end of the suction pipe Attach a float so as to hold the strainer 30cm below the water surface to avoid creating eddies and suck ng and at least 50cm above the bottom to avoid sucking in mud Lay the delivery pipe s up the slope towards the reservoir or tanker filling Fill the pump engine with oil New motor pumps are delivered without engine oil
155. s or pillars and stacks to allow inspection Stack bags with care leaving a sufficient space between the top of the stack and the roof Clean the store daily and never let a stack remain intact for more than a month Inspect the store at least once per week looking for insects signs of damage on the bags water mould fermentation etc the presence of rodents empty bags and refuse not thrown away 11 13 Vector control The principal vectors biology and control methods A OJ A TRAPPING This method never achieves complete eradication by itself It may be used to get rid of the last few survivors of a chemical control campaign or individuals of an isolated and small infestation Spring traps are the only efficient models The key points to follow are Many traps should be used The traps should be placed perpendicular to the rodents trails Rat traps should be left unset for several days so that the rats become used to them except for mouse traps well placed trap does not need bait POISONING POISONED BAIT Two classes of product are used Single dose poisons These are only effective if the animal ingests a lethal dose at the first feed otherwise it will not go back to the bait These substances are extremely toxic and in addition they need special skills and experience in rodent control if their use is to be at all effective For information they
156. s per day The vertical distance in metres between the lowest water level and the highest level to which water must be pumped suction height and delivery height or the total geometric head The variation of the water level m metres Physical information on the site depth of water dlameter and depth of well or borehole sketch with dimensions of river bank lake or channel The height of the s te above sea level The energy source for pumping human animal wind electric motor combustion engine solar etc The average weight which can be easily transported and handled on site Key Inputs Suction head Delivery head Level of pump was Lowest water level Highest water level Sketch and description of site Internal diameter of suction pipe Internal diameter of delivery pipe Length of suction pipe Length of delivery pipe Atmospheric pressure Motorpump unit Non return valve Suction strainer with foot valve Storage reservoir Measuring equipment tape measure level etc 1 2 3 4 5 6 7 8 9 Important The following factors must also be considered The possible presence of large quantities of sand in the water which may damage the moving parts of the pump The presence of salty or brackish water which could produce rapid pump corrosion The ease of maintenance and robustness of the pump the availability of fuel what type of fuel or electriaty the availabibty of tools spare
157. s puits en Afrique tropicale Ministere de la Coop ration et du D veloppement Paris 1981 CAIRNCROSS S FEACHEM Small water supplies Ross Bulletin 10 1978 CAIRNCROSS 5 FEACHEM Environmental health engineering m the tropics an introduction text John Willey 1983 CHLEQ J L DUPRIEZ Eau et terres en fuite L Harmattan Enda 1984 COMITE FRANCAIS D EDUCATION POUR LA SANTE Promotion de la sant document technique n 1 Les eaux us es faciles traiter Minist re de la Sant Paris 1987 DIRECCION DE ENGENIERIA SANITARIA SECRETARIA DE SALUBRIDAD Y ASISTENCIA Manual de saneamiento agua vwienda y desechos L musa M xico 1984 FEACHEM R BRADLEY D GARELICK H MARA D Sanitation and disease health aspects of excreta and wastewater management John Willey 1983 FEACHEM R MC GARRY M Water wastes and health in hot cl mates John Willey 1977 GARANCHER J L assam ssemeni autonome individuel et collectif Editions du moniteur Par s 1986 GAULENE MC PERRAULT A M Lutte antivectorielle contre la trypanosomiase humaine en Haute Volta Th se de doctorat en m decine Toulouse 1982 GENTILINI M DUFLO B M decine tropicale Flammar on 1986 GRET Le point sur la construction de citernes Recueil et stockages des eaux de pluies GRET Paris 1984 Practical books recommended in the field V Bibliography 14 15 16 17 18 19 21 25 G
158. see technical brief Controlled tp or in collective or family refuse pits 1f there is not enough land or the transport for controlled tipping The high water content of this type of refuse does not allow it to be burned in the pits apart from using a lot of fuel the incomplete combustion obtained by this groes a false sense of security It 15 important to respect mlrumum distances to avoid the danger of contaminating water points Distance from water points gt 15 if the pit serves fewer than 10 famulies gt 30m if 1t is a collective pit Distance from dwellings gt 10m 1f the pit serves fewer than 10 families gt 30m if it is a collective pat Dig a hole leaving the earth to one side to be used for daily covering of refuse Check that the bottom is more than 1 5m from the water table It is possible to drive n a metal bar such as reinforcing rod to depth of 1 5m and see if it 15 wet when pulled out Surround the hole with a fence to avoid accidents and prevent the entry of arumals etc Dispose of refuse in the pit each day covering it with a layer of earth to avoid attracting flies and rodents Ashes ar a m xture of ashes and earth may be used for this covering Refill the hole completely and compact the earth when the level of refuse reaches from the surface Inputs 1 pick 1 shovel day 2 buckets to lift out the earth Earth day 1 Refuse day 2 Earth day 2 2m length of reinforang
159. sign should be adapted to the habits of the population particularly concerning the position generally used by women to wash clothes The washing area described here 15 about the s mplest tt 15 possible to build t can be made of local bricks and mortar or of stone masonry Construction Choose a space down the slope from the apron of the water point Lay out the area using a string line Its size will depend on the number of people likely to use it at one ime Excavate about 30cm of soil from this area to create a slope of at least 1 along its length with a V profile across its width see section AA spread layer of sand and gravel on the bottom and compact it well Dig a channel to take water from the water point to the washing area This channel should have a slope of at least 1 and should join the highest end of the washing area Lay bricks on the washing area using a string line and a spint level cementing the joints be careful to keep to the same slope and the same cross section When the cement has set plaster the surface with a strong cement mortar 1 part cement to 2 parts sand and smooth 1t well Powder the surface of the plaster with cement when it is still wet and smooth it again to waterproof the surface Cover the slab with plastic sheeting or thick sacking which is regularly wetted and let 1t cure for 5 to 6 days before using Dispose of wastewater in a soakaway pit evapot
160. sis needs equipment and proper training its use and in the interpretation of results bacteriological analysis should only be considered when Deciding whether or not to treat surface water see the next section Using properly protected groundwater which despite everything is suspected of being the cause of a high incidence of diarrhoeal disease or of being the origin of an epidemic of diarrhoea cholera or typhoid Caution in no case 1s the detection of feecal coliforms in water proof that the water is the origin of an epidemic Detection of heavy pollution indicates that it may be the source of the epidenuc but 1s no proof of this However in this case action must be taken anyway The analysis is done Either a competent local laboratory within 6 hours of sampling after this time the samples are no longer representative of the water to be analysed Or in the field by someone trained in the use of field testing kits As long as the water is chlorinated and the free residual chlorine level is satisfactory see brief Chlorination bacteriological analysis is not necessary nor appropriate 1 Water m camps Should the water be treated Should the water be treated In general Groundwater when correctly protected may be considered not to be polluted unless 1t is proved otherwise and used without treatment Surface water or very shallow groundwater should be considered to be contaminated unle
161. ss it s proved otherwise It is always complicated to take polluted water and treat it It needs equipment skills monitoring and constant control Moreover even when treated polluted water remains potentially dangerous if there is the smallest failure in the treatment system Priority should be given to the choice and protection of the water points Note Certain methods of extracting surface water allow in themselves a strong improvement in quality for instance digging a well several metres from the river bank instead of taking water directly from the river If the only alternative is surface water or groundwater which can not be protected should the water be treated If the WHO directives are to be respected there should be no faecal coliforms in drinking water In the field this would mean being obliged to treat most natural waters with all the disadvantages that this entails t is costly complicated etc In practice a certain level of faecal pollution may be tolerated without much risk because for many water borne diseases the infective dose the number of pathogens which must be ingested to contract the disease is high The decision on whether or not to treat water is a question of common sense It should take into account the risks of not treat ng and what can reasonably be done both immediately and in the future 1 16 Should the water be treated Water camps Some guideline value
162. ssentially dependent on the land surface available and the availability of collection and transport equrpment an mal carts lorries ete Calculate the length of trenches needed using the following formula for a width of 1 5m and a depth of 2m dig 1 linear metre of tench per 200 people per week Choose an area at least 800m from dwellings hving areas should not be downwind from the tp Take care about the distance from water points which should never be less than 50m away and wiuch should be uphull from the ap Fence the area well Dig a surface water dramage ditch around the whole area The lowest corner of this ditch should lead to a soakaway pit Dig the trenches with a mechanical shovel if possible plac ng the earth beside the trenches thus earth 15 used as upping proceeds Operation The refuse 15 collected and taken to the tip then dumped at one end of the trench and covered immediately with earth The following load 15 dumped next to the first and so on until the trench 15 full After 6 months the trenches may safely be redug to make a new tip or to use the contents as a fertilizer Key Inputs Fence construction Trench waiting for use Land Part of trench already full Mecharucal shovel or numerous workers Alley wide enough for the passage of the Stakes and fencing material refuse collection vehicle Poles or tree trunks to build the bridge crossing Drainage ditch the drainage d
163. ssible groundwater pressures lt should rest a sub base of sand several centimetres thick The minimum diameter of the inlet and outlet pipes should be 100mm and ther minimum slope 2 The siting of a septic tank is dictated partly by the pla of the dispersal area infiltration trench The tank should be away from vehicular passage accessible for mamtenance and as near as possible to the building served Make sure that there is enough land available for the underground dispersal system and that the soil allows sufficient rate of infiltration The gases resulting from anaerobic digestion in the septic tank should be evacuated without nuisance This is done by means of a ventilation pipe which extends above roof height taking innto account the wind direction The quantities of chlorine and detergent products used in normal household and hospital activities should not affect the tank s furtctioning It is not necessary to use special additives in the tank to activate t The materials collected the tank nch enough n micro organisms to start biodegradation Take care f the water table is not deep 29 Sanitation gt Technical briefs REFUSE PIT 3 EX Minimum ee 1 5 _____ If Sanitation Technical briefs _ Refuse pit Method In an emergency situation the best way to dispose of household refuse not medical waste 15 burial a controlled tip if possible
164. suspension which g ves it a cloudy appearance turbidity is expressed 1n v NT U units Ventilated improved Latrine ventil e Letrina ventilada Pit latrine equipped with a ventilation pit VIP latrine amelor e mejorada pipe to reduce flies and odouz with a fly screen at the top Virus Virus Virus Extremely small living organisms which can only multiply inside hving_ cells which they parasitise IV Glossary Conversion tables English French Spanish Definition Area or structure designed for washing Washing area de lavage Lavadero clothes and for personal hygiene washing slab wash tub etc Wastewater Eaux us es Aguasservidas Sewage and sullage Well Puits Pozo Hole the ground which enters an underground body of water water table to allow Its abstraction Conversion tables Distances Surface km 0 6214 miles 0386 100ha im 1 0936 yards 1 247iaces 10000007 dm L 0394 ches Im 1196yd 10000 10 76 n 1 609km Imle 259m 240 acres yard 0914m 259ha lfot 0 305m lage 0405ha 4 840yd 30 48cm 0836m 92 imch 2 54cm ife 009 144 inche 930 linde 6 54 Volume Im 1 307 1000 Litres Capacity 35 3266 Ihte 022UK Gal Im 0 06lin 1760 Pints ye 0765 gt 27 fe 02605 3 in x ie z 28 32 litres van in 00675 fluid ounces f 02 Gale 455 litres 8 UK Pints 1 20
165. t latrine VIP Method The VIP uses the movement of ar across the top of a ventilation pipe to draw odours up the pipe and out of the latrine Fires entering the pit are attracted to the light at the top of the pipe and die trying to escape through the mosquito netimg Construction 1 Choose site downhill and at least 30m distant from groundwater points the latr ne or group of latr nes should be not less than 5m and not more than 50m from the dwellings 2 Diga pit assuming that the solids accumulation rate will be about 0 04r per person per year Thus for a group a 25 people maximum number per latrine recommended by WHO t needs a pit of at least 0 04 x 25 Im per year If possible make the pit big enough to last 5 years 3 If t s planned to use a concrete slab 1t may be necessary to build a foundation on the upper part of the pit to support ik 4 Cast a slab see technical brief Concrete slab and place it over the pit The slab should have a second hole belund the defecation hole with a diameter of about 150mm to fix the ventilation pipe 5 Construct superstructure of brick stone wood plastic sheeting etc but preferably using local matenals A spiral form may be suitable if t is acceptable to the population this saves having to fit a door The superstructure should provide a mmimum of darkness so that when flies leave the p t they are attracted to the light coming from the ventilation pipe and not that coming from inside the
166. t or septic Removable slab tank Foundation 75mm pipe for connections Backfill and sand Superstructure Septic tank Inspection emptying hole with cover Outlet pipe towards an underground soakaway system Important As a general rule the pour flush latr ne 1s suitable for regions where water ts habitually used for anal cleansing In other cases it is preferable to use dry pit latrines It 15 essential to have a water point close by so that the tonet may be flushed after each defecaton If the water supply falls closure of these latr nes and temporary replacement by a system not using water should be considered Maintenance should be frequent if these toilets block they should be unblocked quickly or matenal will solidify and plug the water trap 27 Sanitation Technical briefs Section AA Longitudinal section 1 3 of length 2 3 times the width gt AL Example of design calculation for a septic tank Design calculation for a septic tank for a health centre of 20 beds and a water consumption of 50 htres bed day The effluent from the septic tank is to be disposed of in an infiltration trench It is estimated that 80 of the water consumed enters the septic tank Assuming a 3 days retention time the volume of the tank will be 0 04m bed day x 20 beds x 3 days retention time 2 4m or 2 4m long 1m wide and 1m deep The frequency of emptying accumulated solids if one assumes that the
167. terial IV 3 IV Glossary English Biodegradation decomposition Burying c Calcium hypochlonte Candle filter Catchment Catchment nng Chemucal analysis Chlorinated hime Chlonne Chlorine compound Chlonne demand Combined residual chlor ne IVA French Biod gradation Enfouissement Hypochlonte de calaum Bougie Captage Buse de captage Analyse chimique Clorure de chaux Chlore Produit g n rateur de chlore Demande en chlore Chlore r siduel combin Spanish Biodegradaton Enterramiento Hipoclonto de calcio Filtro de porcelana Captaci n Tubo de captaci n An l s s qu mico Cloruro de calcio Cloro Derivado del cloro Demanda de cloro Cloro residual combinado Definition Natural process of destruction of organic material by microbiological activity Action of covering with earth e g refuse see controlled tipping Chlonne generating product in a form containing 65 to 70 available chlorine made by reachng chlor ne with calaum hydroxide Ceramic filter element pore size 0 451 Part of a well below the static level of the water table which allows water to flow into the well or the emergence zone Of a spring where water may be collected Perforated or porous concrete cylinder sunk into the water table through whuch water passes Identification of undesirable or toxic chemical substances whose maximum pe
168. the courtyard of a hospital Cut a 200 Litres oil drum in two Hammer the cut edges to avoid injuries Fix a cover on the open end with hinges Pierce about 20 holes in the bottom with a large nail to let decomposition liquids drain out Fix a handle on the cover for opening and two on the sides for carrying Pannt the inside of the dustbin with ant corrosion paint Pamt the outside in a bright and attractive colour to make it clearly visible Make a support m metal or wood for example to raise the bottom of the dustbin from the floor Dig a hole where the dustbin will be placed 50cm deep the same diameter as the dustbin and fill xt with stones to dram leachates Place the support on the stones and the dustbin the support Inputs Cover 1 drum 2001 Handles 1 cold chisel or metal saw Hinge Wire nuts and bolts or pop r vets for fix ng handles 1 2 metal drum 1 hinge or piece of rubber or leather for Pierced bottom attaching cover Support Wood or metal and stones for support Stones drainage Ant corrosion and coloured paints Hammered edges 1 2 3 4 5 6 7 8 Important Attach the cover in such a way that it falls shut every time it is let go This Is the only way to be sure that the dustbin 15 always covered Allow one dustbin for every 10 15 houses and others along roads and n public places schools markets etc Organise refuse
169. these problems in several ways in the course of medical treatment after poisoning as users during a specific vector control programme as trainers in public health This chapter should within the limited context of our actions allow us to choose and to use suitably some selected insecticides to know the precautions for their use and finally to be able to take emergency medical action in the case of poisoning But it is also intended as a warning against the apparent case of use and effectiveness of these products The use of pesticides is costly is never without risk and is not always effective In the context of a medical programme it may be conceived either in an emergency phase epidemic due to a vector Or when the control of vector breeding sites is a problem difficult to locate far away etc Chemical control should always be planned alongside a programme of improvement of the site and or of general l ving conditions and hygiene the removal of stagnant water and refuse scrub clearance reduction of living density water and sanitation services etc If no action is taken in this direction even the most active and powerful insecticide would have little impact in the long term The pesticides are frequently used in agriculture often however the users are not informed of the precautions to take during the transport and use of these products The health problems which result may go unnoti
170. tion Schistosomiases Leptospiroses Problems limited to certain regions Dracunculias s Guinea worm Problems rare in the situations considered here Malana yellow fever dengue onchoceraasis etc In schistosomiasis caused Schistosoma haematobium transmission occurs via ur ne and not via faeces 1 8 Water supply I Water in camps Water supply Different types of water Potentally three types of water may be available SURFACE WATERS STREAMS RIVERS LAKES PONDS RESERVOIRS DAMS It is generally heavily polluted particularly during the rainy season quantity vanes with the season It generally needs complex treatment before use Nevertheless certain catchment methods allow a significant improvement of water quality shallow wells dug close to river banks river bed filters infiltration galleries GROUNDWATERS WELLS BOREHOLES SPRINGS Deep groundwater boreholes deep wells certain springs Generally clear and of good bacteriological quality filtered by percolation through rocks Sometimes containing substances rendering it undrinkable because of its taste or because of toxicity Not generally subject to much seasonal variation in quality or quantity Shallow groundwater wells a few metres deep certain springs groundwater near water courses The higher the water table the lower the bacteriological quality tends to
171. tions open wounds domestic refuse dead bodies etc They are important in the spread of conjunctivitis plan yaws trachoma dysentery etc Glossinia Tsetse fly vector of trypanosomiasis and glossinnia black fly vector of onchocerciasis demand the implementation of a specific programme because of their medical importance and their biology the complexity of such a programme is beyond the scope of this guide Control metbods Larval sites ie the places where eggs are laid and where the larvae develop are very often a product of human activity The basic principle of all control measures should be to reduce or remove these sites or to prevent access by flies Without these environmental hygiene measures all control efforts are in vain In practical terms these measures focus Animal excreta cleaning of stockraising areas Refuse organize collection and ensure disposal by burning or burial under at least 30 cm of soil Make covered refuse containers available in particular in kitchens laboratories and health centres Spilled food make smooth floors in feeding centres smoothed cement or plastic sheeting to aid cleaning Wastewater ensure good removal and disposal particularly at washing areas for clothes and cooking ustensils Vector control The principal vectors biology and control methods Recourse to chemical products should be avoided as much as possible because of the rapidity
172. tration allows a highly effective microbiological purification of water m addition to mechanical purification by the sand This microbiological treatment 15 due to the action of a brolog cal layer called the Schmutzdecke which develops at the surface of the filter This layer actively retains and destroys helminth eggs bacteria and some viruses Constraction 1 Pa nt the insides of two 2001 drums Fix an inlet pipe about 5cm from the bottom of one drum which will be used for the prefilter as shown n the sketch 2 a layer of large stones on the bottom of this drum 4 making sure there is a plug hole at the bottom Tf there is not then make one 3 Place a perforated plate g the top cut off the drum on top of the stones 2 to act as a support for a layer of coarse sand 4 Place a 30cm layer of coarse washed sand 1 2mm dia on top of the metal plate 5 Fix a pipe connecting the two drums near the top to take water from the prefilter to the filter 6 Make sure the second drum has a plug hole in the bottom Make a hole about 5cm from the bottom and insert a perforated pipe 9 A length of PVC pipe with many slots cut with a saw 1s Suitable 7 Bury the perforated pipe in a bed of gravel 8 which covers it by at least 8 Then add a layer of at least 70cm of washed sleved fine sand 7 The ideal diameter is 0 2 to 0 5mm or in any case less than 1 5mm The Schmutzdecke will develop at the surface of this sand 9 Place a f
173. tte antivectorielle en sant internationale OMS Gen ve 1973 OMS La trypanosomase afr caine pid miologie et lutte OMS Gen ve 1986 RAJAGOPALAN S SHIFFMAN Mesures simples contre les maladies intestinales OMS Gen ve 1975 RODHAIN F PEREZ C Pr cis d entomologie m dicale et v t rinmre Malone Sa Editeur Paris 1985 ROSS INSTITUTE Control of domestic flies Ross Institute Bulletin n 5 1982 ROSS INSTITUTE Insecticides Ross Institute Bulletin n 1 1981 SIMMONDS 5 VAUGHAN P GUNN S W Refugee community health care Oxford University Press 1983 SOGREAH Les pompes et les petites stations de pompage Mirust re de la Coop ration Pans 1978 STERN P et al Field engmeering introduction to development work and construction in rural areas Intermediate Technologies London 1983 TDRI Food storage manual TDRI 2nd edition England 1983 THEUNYNCK S HALTER Filtre sable et charbon de bors Fiche n 683 GRET Pans Practical books recommended in the field V Bibliography V 5 V Bibliography 41 42 45 TROPICAL HEALTH TECHNOLOGY Medical laboratory manual for tropical countries Volume Monica Cheesbrough 1984 U S A LD Water for the world Technical notes Agency for international development Washington UNICEF Aude aux situations d urgence UNICEF Gen ve New York 1986 WHO Chemical methods for the control of arthropod v
174. ty is indispensable health centres open at night isolation ward cholera camp etc It 1s also desirable n the camp as a whole as it reduces insecurity and allows better access to defecation areas But the installation of an electricity supply system may cause problems with the local population if it has no access to electricity itself which is often the case Conclusion More often than not site planning has to be done for a camp which is already established and t 15 therefore a job of reorgan zation which is much more difficult to achieve there are the difficulties in doing a topographical survey because of congestion in measuring distances in overcoming reluctance to change on the part of both the refugees and the aid teams etc To avoid later becoming overtaken by events it is important to establish short and medium term plans from the beginning allowing for the probable increase in the population 12 I Water in camps of Displaced people The objective of this section is to suggest some concrete responses to water supply problems faced in camps of displaced people However most of the points considered concern water problems tn general and apply to any deprived situation A Needs B Water related health risks C Water supply D Assessment of water quality E Should the water be treated F Simple water treatment techniques Water related health risks I Water m camps Needs Like any
175. uent problem than the presence of chemical substances at toxic concentrations In practice which analysis should be done and when TURBIDITY CLOUDY APPEARANCE The presence of suspended solids is always a problem the water is unpleasant to drink there is a sediment etc even if 1t does not necessarily mean that the water is polluted But it is particularly important to take the turbidity into account if the water needs treatment The measurement of turbidity may be done with special equipment graduated plastic tubes but generally simply looking through the water in a transparent container gives enough information CHEMICAL ANALYSIS In emergency situations a blind eye is usually turned to the acceptability of the taste and smell of water However a laboratory chemical analysis may be requested if a long term water supply is being planned if there are part cular reasons to suspect chemical pollution BIOLOGICAL ANALYSIS In other words how to tell if water contains pathogens Principle The pathogenic organ sms which may be present in water are too numerous and too various to be identified individually in practice bacteria protozoa helminths etc As their presence is always linked to f cal pollution except for Guinea worm 1t is preferable to look for organisms which are indicators of this pollution The indicator organisms generally looked for are the fecal coliforms principally Escheri
176. urtight opaque non metallic contamer away from light and heat and should be replaced every 1 to 2 weeks Calaum hypochlonte and NaDCC are recommended for general disinfection greater stability and high chlonne content NaDCC 15 completely soluble is less corrosive and 1s not affected by LATA rules on the air transport of corrosive substances Technical br efs Method Chlorination ts one of the best methods of treating nsi ale relatively simple effective and easy to measure In spite of this relative simplicity tf should not be forgotten that in an emergency situation it is always preferable to use I Water in camps groundwater source which can be protected and monitored in terms of environmental hygiene see technical brief Protecting a well Chlor nah on demands staff trained in the technique and in its monitoring as well as good logistics supply of chlorine produci storage etc In practice Only the chlorinat on of a known volume of water in a reservoir is discussed here The pr naple is to add enough chlor ne generating product to destroy all the organic matter contained in the water and to leave a small frachon of chlorine available for dealing with any possible remtroduction of orgaruc matter To determine how much chlorine product to add the chlonne demand is measured 1 Prepare a 1 chlorine solution see technical bnef Chlorine generahng products 2 Take 3 or 4 non metallic containers of known
177. us permanent For collectroe facilities several pits may be constructed in series Construction 1 Choose the site see technical brief Simple pit latr ne 2Dig the double pit large enough so that each half pit has a 2 year accumulation capaaty see the chapter Calculation of the effective volume of a latrine pit 3 Line the pit brick stone etc leaving regular gaps n the construction to allow Hquids to infiltrate and build up the watertight part tlon wall between the two equal parts 4 Place slabs with a defecation hole over each twin pit These slabs should not cover the prts completely one or more removable slabs should cover the back of each pit so that it can be emptied 5 Construct the superstructure which should include both defecation holes in the same cubicle Only one hole is used at a while the other is blocked 6 After a period of 1 to 3 years the first pit Is full block the first hole and unblock the second After a further 1 to 3 years the second pit is full in turn take out the contents of the first pit which has formed compost and reuse the pit n this way the alternation between pits may be repeated indefinitely The material taken out is inoffensrve and does not resemble excreta at all It 15 an excellent fertihser Key Inputs Defecation hole in service Shovel pick miner s bar Defecation hole on standby blocked Mason s tools Slabs Bncks Superstructure spiral or with a door C
178. vapotranspiration Evapotranspuaci n Removal of water into the air by a combination of direct evaporation and transpiration by plants F Faeco oral Transmission Transmici n Transmission of pathogens from f cal transmission f co orale oro fecal matter to the digeshve system via the mouth fecal contamination of water food hands etc Ferrocement Ferroament Ferrocemento Technique of constructing walls by applying layers of cement mortar to a framework of wire mesh Filtration Filtration Filtraci n Passage of water through a porous layer filter which traps suspended sold Free residual Chlore r siduel Cloro residual Fraction of available chlorine added to chlorine libre libre water which remains in excess and which still has disinfectant power after 30 minutes contact time 0 3 to 0 5mg I G Grease trap Bac d graisseur Trampa para grasa Construction for separating fatty material from wastewater before disposal n a soakaway pit or infiltration field Groundwater Eau souterraine Agua subterr nea Infiltrated water contained in underground layers forming a body of water H Helnunths Helminthes Helmintos Parasitic worms of man and other an mals g ascar s Hot sterilizer Poupinel Pupinel Equipment for sterilizadon by hot air dry heat during 120 minutes at 160 C or 90 munutes at 170 C Human wastes D chets humains Desechos humanos Faces and urine excreta Hygiene Hygi ne Higiene Practices related to keeping
179. volume e g 201 buckets 3 Fill the containers with some of the water to be treated 4 Add to each bucket a progressively greater dose of 1 solution with a syringe 1st contamer imi 2nd container 1 5ml 3rd container 2ml 4th container 25m 5 Wat 30 minutes essential this is the minimum contact time for the chlorine to react 6 Measure the free chlonne residual in each bucket see technical brief Monitoring chlorination 7 Choose the sample which shows a free residual chlonne level between 0 2 and 0 5mg l Example Chlorination of water in a 2 0001 reservoir Follow steps 1 5 above The free residual chlor ne levels of the water n the buckets measured half an hour after adding 1 15 2 and 2 5ml of 1 chlorine solution respectively are as follows 1 Omg l 2 01mg l 3 04mg l 4 1mg The dosing rate chosen therefore wall be that for bucket number 3 result between 0 2 and 05mg l If it needs 2ml of 1 solution to chlonnate 201 of water at the correct dosage then 1t needs 100 times as much to chlorinate 2 0001 e g 100 x 2ml 200 ml of 1 chlorine solution to be able to adjust the dosage rate to the situation or painted Important Never chlor nate turbid water because the suspended particles can measurement of free residual chlorine may indicate a satisfactory result there is no way of knowing 1f the chlorine actually comes into contact with all the pathogens Water to be chlor
180. water detergent 10 sodium bicarbonate Leave n the container for several hours stirring from t me to time then rinse with clear water All the water used in this process should be disposed in a hole in the ground It is preferable to avoid reusing the drums for food or water If for a good reason this rule cannot be respected make sure that the above measures have been taken Spraying equipment Vector control Spraying equipment The type of equipment depends on the product being used and on the type of treatment surface spatial etc Powders Soup spoon treatment of individuals Powder blower hand or knapsack treatment of the ground bedding people Pierced tin or jute sack treatment of floors of vegetation Liquids Aerial application Just for nformation Atomisers This equipment gives an immediate and temporary treatment by creating a fog condensation of the solvent in the air into very fine droplets It 1s an engine driven machine portable or mounted on a vehicle Sprayers This equipment gives a persistent treatment by spreading the insecticide n visible drops on walls floors stretches of water etc Four techniques are used liquid 15 pumped in a tank The liquid is expulsed in a watertight receptacle by the compression of its surface air The liquid is carned away by a gaseous current The liquid is expulsed by centrifugation 11 19 Technical
181. which thus plays only a secondary role g plague rodent excreta e g salmonella leptospirosis bite Biology The black rat The adult measures about 40cm from head to tail and weighs 250g The muzzle is pomted the ears round and protruding from the fur and the eyes protuberant The animal may be dark grey or brown The nest is built generally on the ground in vegetation or in trees and exceptionally in a burrow or sewer In houses the nests are generally built under the roof and the territory is more aerial than terrestrial with a radius of about sixty meters Its diet is very varied vegetable and animals Sexual maturity is reached at two months 5 litters of 7 to 8 rats per month The brown rat or sewer rat The colour is generally brown It s bigger than the black rat and may exceed 400g Its muzzle is rounded and the eyes and ears are smaller than those of the black rat This species 15 not well adapted to hot countries Nests are built in burrows entrance diameter about 8cm The diet is less varied than that of the black rat The brown rat prefers refuse and human wastes Its biology is identical to that of the black rat 12 The principal vectors biology and control methods HI Vector control The domestic mouse This is a well known universal species Its biology is similar to that of the rats It can survive with the water enclosed in food flour etc whereas the rat
182. with earth Key Permeable soil 1 tape measure Pipe diameter 50 100mm Shovels picks Compacted earth _1 wheel w Cleared space at the end of the pipe Straw or plast c sheet 1 pipe 50 100mm diameter PVC or cement Stones Stones enough to fill the soakaway pit Flat stone Straw plast c sheet Important To determine the dimensions of the pit it 15 important to evaluate the infiltration capacity of the soil and to allow for a possible increase in the amount of wastewater to be disposed of Install a grease trap before the soakaway pit if it ls meant to take wastewater from k tchens in order to avold clogging by fats see technical brief Grease trap The straw or plastic sheet over the stones prevents soil from getting between the stones and blocking the system The bottom of the soakaway pit should be at least 1m above the water table dunng the wettest penod and 1m above any impermeable layers If this is not possible opt for a system of infiltration trenches see technical bnef Infiltration trench Plant the area of the soakaway pit with grass 1f water or wind erosion are severe 41 II Sanitation Technical briefs INFILTRATION TRENCH Longditudinal section Multiple trench system Cross section mini 1 5m Technical briefs II Sanitation Infiltration trench Method Infiltration trenches may be used for the underground d persal of wastewater from kitchens

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