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Environmental Health in Emergencies, 2007

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Environmental Health in Emergencies

Technical Notes on Water and Sanitation

EHA Publication No. 20 Kathmandu March 2007

ENVIRONMENTAL HEALTH IN EMERGENCIES Technical Notes on Water & Sanitation

Health and Environment Emergency and Humanitarian Action

World Health Organization

Kathmandu Nepal, March 2007

Kjaergaard, Erik; Heijnen, Han; Adhikari, Damodar; Adhikary, Sharad .-ed Environmental health in emergencies: technical notes on water and sanitation, Kathmandu: WHO, 2007. 55p.; illus (EHA Publication No. 20) 500 copies printed Keywords: emergency water supply; water quality testing; water purification; disinfection; environmental health; hygiene; solid waste management; dead body management

Printed by the WHO Emergency and Humanitarian Action (EHA) Programme with financial contribution from Swedish International Development Agency (SIDA)

For feedback and further information, please contact: WHO Environmental Health Unit Han Heijnen, Environmental Health Advisor heijnenh@searo.who.int Sharad Adhikary, National Professional Officer adhikarys@searo.who.int

© World Health Organization, March 2007 This document is not a formal publication of the World Health Organization (WHO), and all rights are reserved by the Organization. The document may, however, be freely reviewed, abstracted, reproduced or translated, in part or in whole, but not for sale or for use in conjunction with commercial purposes. The views expressed in documents by named authors are solely the responsibility of those authors.

Preface The World Heath Organization is pleased to present this publication on effective water and sanitation measures during emergencies. Given the high risk of natural calamities and prolonged complex emergencies in Nepal, it is important to have sound public health guidelines and trained staff in place to ensure provision of clean water, basic sanitation and good hygiene practices. Past experience has shown that simple methods to improve environmental health reduce excess mortality and morbidity in emergencies. Nepal is exposed to multiple hazards. The country is located in an active seismic zone which could anytime transform into an emergency situation as witnessed in Gujarat in 2001 and in Pakistan in 2005. Steep hillsides are vulnerable to earth slips and landslides especially during the rainy season, where trails and roads often get cut off. During the monsoon season, several parts of the Terai get flooded, for a few days and sometimes for weeks. These hazards have an impact on water and sanitation and compel us to consider preparedness, mitigation and relief measures to minimize the health consequences of a natural calamity and restore services as soon as possible. In view of the increasing vulnerability of the population in the region, the World Health Organization in 2003 initiated a project to develop a capacity building strategy for water, sanitation and hygiene in emergencies. This strategy of the WHO South East Asia Regional Office aims to support national counterparts and other organizations involved in emergency preparedness and disaster response with authoritative advice and information on water supply and sanitation, in order to protect the health and wellbeing of vulnerable populations. The rationale for the WHO strategy is: • There is better global understanding of how disasters impact on people’s livelihoods, health and wellbeing. Disasters cannot be ignored as an ‘isolated issue’ but must be treated as an integral component of (national/local) development The poor are often most vulnerable to disasters and their health impact. Disasters are obstructing progress towards achieving poverty alleviation and the Millennium Development Goals Disasters often disrupt water supplies, sanitation facilities and people’s hygiene practices, exposing the affected population to significant health risks. Safe water supplies and sanitation are often priority public health concerns in an emergency, and are certainly perceived to be so by the affected population

•

The fourteen illustrated technical notes presented in this publication is one of the initiatives to enhance the capacity of emergency and relief staff in dealing with water and sanitation. The notes were prepared jointly by the WHO South East Asia Regional Office and the Water, Engineering and Development Centre at Loughborough University, United Kingdom. The papers cover various aspects of environmental health in emergencies such as the minimum water quantity needed; measuring of residual chlorine in water; cleaning and disinfection of wells, boreholes, water storage tanks and tankers; emergency sanitation and essential hygiene messages. The objective of these technical notes is to assist those working immediately or shortly after an emergency to plan and execute appropriate responses to the urgent and medium-term water and sanitation needs of the affected population. The notes are relevant to a wide range of geological and topographic settings, and to various types of natural disasters and complex emergencies. During the Tsunami disaster response in 2004-2005, the fact sheets proved their worth. They are suitable for field technicians, engineers, hygiene promoters, as well as programme staff. WHO Nepal is currently working on the fact sheets to make them more applicable in the Nepal context. We intend to add more sheets to address particular concerns that may be important in the case of an earthquake. We welcome comments from the users of the sheets in order to make them relevant and useful. I hope this publication will be a useful guide to the staff and volunteers who will be called upon to respond during crisis.

Dr Kan Tun WHO Representative to Nepal

Table of Contents 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. Cleaning and disinfecting wells in emergencies Cleaning and disinfecting boreholes in emergencies Cleaning and disinfecting water storage tanks and tankers Rehabilitating small-scale piped water distribution systems Emergency treatment of drinking water at point-of-use Rehabilitating water treatment works after an emergency Solid waste management in emergencies Disposal of dead bodies in emergency conditions Minimum water quantity needed for domestic use in emergencies Essential hygiene messages in post-disaster emergencies How to measure chlorine residual in water Delivering safe water by tanker Emergency sanitation – planning Emergency sanitation – technical options 1 5 9 13 17 21 25 29 33 37 40 44 48 52

Cleaning and disinfecting wells in emergencies World Health Organization Steps of cleaning and disinfection Figure1 outlines a five stage approach to cleaning and disinfecting wells after natural disasters. It is an emergency approach designed to rehabilitate wells so that they produce water of a similar quality to that supplied before the disaster. Step 1: Inventory of existing wells

Step 2: Cleaning and rehabilitation of wells

Step 1: Inventory of existing wells The disaster may have contaminated or damaged a large number of wells. The first step must be to select which wells should be repaired first. The following actions should help you to make your selection. Further well cleaning including dewatering No QUESTION Test turbidity levels. Are they 5NTU? Yes Step 3: Disinfection of wells

Meet with community leaders and ask them to briefly outline which wells serve which sections of the community. Select the wells that are most commonly used for drinking water. Assess the type and extent of damage to the top of the well. Estimate the amount of silt and debris in the well. Test the pump to see if it is still working or determine what repairs are necessary. Estimate resources needed for repairs (personnel, equipment, time and materials). Select the wells that are used most and are easiest to repair first.

Step 4: Dewatering of wells

Step 5: Monitor chlorine levels

Figure 1. Steps for cleaning and disinfecting a well

Step 2: Rehabilitation and cleaning of wells Disinfecting a well without first removing the source of contamination provides only temporary health protection. Rehabilitation may include: 1. 2. Repair/replacement of the pumping mechanism. Removal of polluted water and debris from well using either buckets or pumps. Sealing the top of the well using a clay sanitary seal built around top of well (Figure 2).

3. Damaged well head and surround

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Cleaning and disinfecting wells 2.5m - 3.5m diameter apron 150mm thick (cast in situ) Seal

Check turbidity and pH Following cleaning and repair, allow the water level in the well to return to its normal position. Measure the turbidity and pH levels to check if chlorination will be effective. This can be done using simple hand held equipments similar to that shown in Figure 3. Never chlorinate turbid water because the suspended particles can protect the micro-organisms. Table 1 outlines why pH and turbidity are important and what can be done to ensure guideline levels are met. If the turbidity of the well water is greater than 5NTU after the cleaning and rehabilitation stage, remove all water in the well once again and scrub the well lining with a strong concentration of bleach in water. Allow the well to refill with water and test turbidity levels again to ensure compliance.

Concrete slab

Compacted clay

Hardcore foundation

Figure 2. Sealing the top of a well

Construction of a drainage apron and head wall around the well to prevent surface water, insects and rodents entering the well. Relining the well to reduce subsurface contamination.

Examining the turbidity of water

Bleach gives off chlorine gas which is very dangerous. Try to clean the well lining from outside the well using a long handled brush. If you must enter the well either wear full protective clothing and breathing apparatus and provide a strong air flow inside the well to carry away the chlorine gas. Taking a water sample from a well

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Cleaning and disinfecting wells The level of residual chlorine in mg of chlorine per litre of water (mg/l) is determined by dissolving a chlorine testing tablet in the water supply under test, in chamber (A). Compare the colour produced with the standard colours on the wall of chamber (B). A B C

1Dml Chlorine DPD colour 1.0 8.0 0.8 0.6 0.4 5.0 3.0 2.0

0.2 mg/l 1.5

Note: A third chamber (C) would be used if a higher chlorine residual is to be measured. A separate fact sheet is available on chlorine testing.

Testing chlorine levels using a comparator Figure 3. A comparator

Step 3: Disinfection of the well WHO endorses the disinfection of drinking water in emergency situations. There are various ways of doing this but the most common is chlorination as it leaves a residual disinfectant in the water after chlorination. Chlorine has the advantage of being widely available, simple to measure and use and dissolves easily in water. Its disadvantages are that it is a hazardous substance (handled with care) and is not effective against all pathogens (e.g. cysts and viruses, which require higher chlorine concentrations). The chlorine compound most commonly used is calcium hypochlorite as high test hypochlorite (HTH) in powder or granule form. Also used is sodium hypochlorite in liquid bleach or bleaching powder form. Each chlorine compound has a different amount of usable chlorine depending on the quantity of time the product has been stored or exposed to the atmosphere and the way it is made.

Testing pH level of water

Table 1. Physico-chemical parameters Parameter pH Turbidity WHO GDWQ 6–8 Why? pH of 6.8-7.2 is required to reduce level of chlorine required. High turbidity (>5NTU) requires more chlorine to oxidise organic matter Corrective action If pH is less than 6 add hydrated lime (calcium hydroxide) Dewater well and rebleach well lining using chlorine solution

< 5NTU (20NTU emergency limit)

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Cleaning and disinfecting wells The best type of chlorine in an emergency is HTH as this normally contains 50 to 70% chlorine. Box 1 outline methods for calculating appropriate chlorine doses for HTH granule chlorine. The amount of chlorine needed will depend on the volume of water in the well. Add 1 litre of 0.2% chlorine solutions for every 100 litres of water in the well. Stir the water in the well thoroughly with a long pole and then allow the water to stand for at least 30 minutes. Box 1. Calculating the chlorine dosage for disinfecting a well using Calcium Hypochlorie (HTH) Equipment • 20 litre bucket • HTH chlorine granuals or powder Method • Calculate the volume of water in the well using the formula: V = πD2 x h 4 Where V = volume of water in the well (m3) D = diameter of the well (m) h = depth of water (m) π = 3.142 • • Fill the bucket with clear water from the well. Add 50g of HTH and stir unitl disolved.

Step 4: Dewater the well Following the contact period, remove all water in the well using a pump or bucket. When the well has refilled, wait a further 30 minutes and measure the chlorine concentration using a comparator. If the residual chlorine concentration is less than 0.5mg/l the well is safe to use. If the concentration is greater than 0.5mg/l, remove all the water from the well again and repeat the process.

For every cubic metre (m3) of water in the well add 10 litres (half bucket) of the chlorine solution.

Do not allow anyone to use the well during the cleaning process. The water will have a strong concentration of chlorine that will give it a bad taste and smell and could be dangerous.

Further information Godfrey, S. (2003), ‘Appropriate chlorination techniques for wells in Angola’, Waterlines, Vol. 21, No. 5 pp 6-8, ITDG Publishing, UK. Wisner, B. and Adams, J. (2002), Environmental Health in Emergencies and Disasters: A practical guide, WHO, Geneva.

A reconditioned well with windlass and bucket

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Cleaning and disinfecting boreholes in emergencies World Health Organization Steps of rehabilitation Figure1 outlines a five stage approach to cleaning and disinfecting boreholes after natural disasters. It is an emergency approach designed to rehabilitate boreholes so they produce water of a similar quality to that supplied before the disaster.

Step 1: Assessment of damage The disaster may have damaged the above ground or below ground parts of the borehole. This may have led to contamination of the borehole. The first step must be to assess the extent of the damage to the borehole and pump. The following actions should help you to make your assessment.

Meet with community leaders and ask them to briefly outline which boreholes serve which sections of the community. Assess the type and extent of damage to the top of the well. Remove the handpump or mechanised pump from the borehole. Estimate the amount of silt and debris in the borehole using a steel pipe the length of whole depth of the well. Check if borehole casing is damaged or out of line. Do this by inserting the steel pipe. If it is out of line the pipe will catch against the side of the borehole. If this happens, select other sites. Test the pump (and motor) to see if they are still working or what repairs are necessary. Estimate resources needed for repairs (personnel, equipment, time and materials). Select the boreholes that are used most and are easiest to repair first.

Step 1: Assessment of damage

Step 2: Rehabilitation of borehole

Step 3: Pump test borehole

Flush borehole No QUESTION Does quantity equal demand? Yes

Step 4: Disinfection of borehole

Step 5: Dewater borehole

Figure 1. Steps for cleaning and disinfecting a borehole A damaged handpump and surround

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Cleaning and disinfecting boreholes Step 2: Rehabilitation of boreholes Before the borehole can be cleaned, all silt and debris should be removed. The following steps may be followed: 1. If not already removed, take out the pump and motor from the borehole and clean and repair them. Flush the sediment from the borehole using compressed air or water. Place the compressor hose in the borehole and blow out the sediment. 3. To remove the silt from the borehole filter insert the end of the compressed air hose at the head of the filter. Open the valve until water starts coming out of the top of the borehole. Close valve 1 and open valve 2 until no more air is heard coming out. Repeat until the water coming out of the borehole is clear.

Valve (2) closed Vent to atmosphere

Compressed air lifts column of water - go to step 3 as soon as water is seen to erupt at surface (or for a set time 1-3 seconds)

Valve (1) open Compressed air supply

Removing components of a pump 5000 litre water tanker Water hose High pressure water hose Compressed air hose Water overflowing to waste 2.5m - 3.5m diameter apron

Figure 3. Removing silt with a compressed air hose

150mm thick (cast in situ) Concrete slab

Water pump and compressor Casing 3m

Water table

Hardcore foundation Borehole casing Compacted clay

Screen

Figure 2. Flushing out a borehole

Figure 4. Sanitary seal

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Cleaning and disinfecting boreholes 4. Reseal the top of the borehole using a clay sanitary seal built around the top. Construct or repair the drainage apron and head wall around the borehole to prevent surface water, insects and rodents entering the borehole. Replace the pump in the hole and check that it is working and the water it is producing is clear of silt. If the water is silty, remove the pump and flush out the borehole. If, after two flushes, the bore is producing silty water, the underground filter is probably broken and no further attempt at repair should be made. Box 1. Estimate flow rate from a borehole Put a bucket under the outlet from the pump and measure how long it takes to fill. Amount of water pumped in 1 hour is: 6. ⎛ AxC ⎞ ⎟ −B ⎜ ⎝ B ⎠

Step 3: Pump test Handpumps Once the pump is replaced in the borehole, operate it in the normal way. Ask the local community to assess whether the amount produced is similar to what was produced before the disaster and to compare how easy the pump is to use. If pumping is difficult and a small amount of water is produced it could be a blockage or the pump could be broken. Re-check the pump mechanism and reflush the borehole.

Where: A = The volume of the bucket in litres B = Number of seconds taken to fill the bucket C = 3600 seconds Q = flow (litres/hour)

Compare the flow rate with what was produced before the disaster. If it is significantly less check the pump and motor for damage and/or flush the borehole again. If this does not change the flow rate either accept the lower flow or abandon the hole.

Motorised pump Measure how much water the pump produces using the procedure shown in Box 1 and the Figure 5 below. Oil drum to collect and measure water flow Stand to support pipe Measuring tape with float on the end to measure depth to water level Borehole casing

Step 4: Disinfecting the borehole Following the rehabilitation of the borehole, test the levels of turbidity and pH to ensure that chlorination will be effective. This can be done using simple hand-held equipment. Never chlorinate turbid water because the suspended particles can protect the microorganisms. Table 1 outlines why pH and turbidity are important and what can be done to ensure guideline levels are met. If the turbidity of the water is greater than 5NTU after the cleaning and rehabilitation stage, pump out the water, allow the well to refill and then re-test turbidity levels. WHO endorses the disinfection of drinking water in emergency situations. There are various ways of disinfecting wells but the most common is chlorination as it leaves a residual disinfectant in the water afterwards.

Water table

Submersible pump

Figure 5. A pump test

Table 1. Physico-chemical parameters Parameter pH Turbidity WHO GDWQ 6–8 < 5NTU (20NTU emergency limit) Why? pH of 6.8-7.2 is required to reduce level of chlorine required. High turbidity (>5NTU) requires more chlorine to oxidise organic matter Corrective action If pH is less than 6 add hydrated lime (calcium hydroxide) Dewater well and rebleach well lining using chlorine solution

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Cleaning and disinfecting boreholes The chlorine compound most commonly used is calcium hypochlorite as high test hypochlorite (HTH) in powder or granule form. Also used is sodium hypochlorite in liquid bleach form. Each chlorine compound has a different amount of usable chlorine depending on the quantity of time the product has been stored or exposed to the atmosphere. The best type of chlorine in an emergency is HTH as this normally contains 50 to 70% chlorine. Box 2 outline methods for calculating appropriate chlorine doses for HTH granule chlorine. Box 2. Disinfecting a borehole using Calcium Hypochlorie (HTH) Equipment • 20 litre bucket • HTH chlorine granuals or powder Method • Fill the bucket with clear water from the borehole • Bleach gives off chlorine gas which is very dangerous. Try to clean the well lining using a brush on the end of a series of connected 25mm diameter metal pipes. • Add 50g of HTH powder and stir until disolved Calculate the volume of water in the borehole using the formula:

The amount of chlorine needed will depend on the volume of water in the borehole. Add 1 litre of 0.2% chlorine solutions for every 100 litres of water in the borehole. Leave the water undisturbed for at least 30 minutes.

V = πD2 x h 4 Where V = volume of water in the well (m3) D = diameter of the well (m) h = depth of water (m) π = 3.142 • • Fill the bucket with clear water from the well. Add 50g of HTH and stir unitl disolved.

Do not allow anyone to use the well during the cleaning process. The water will have a strong concentration of chlorine that will give it a bad taste and smell and could be dangerous.

For every cubic metre (m3) of water in the borehole add 10 litres (half bucket) of the chlorine solution.

Step 5: Dewater borehole Following the contact period, dewater the borehole once again using compressed air. When the borehole has refilled, wait a further 30 minutes and measure the chlorine concentration using a comparator. If the residual chlorine concentration is less than 0.5mg/l the borehole is safe to use. If the concentration is greater than 0.5mg/l, remove all the water from the well again and repeat the process.

Further information Godfrey, S. and Ball, P. (2003) ‘Making Boreholes Work – Rehabilitation strategies from Angola’, 29th WEDC Conference Proceedings, WEDC, Loughborough, UK. Ball, P. (1999) Drilled Wells, SKAT Publications, Geneva, Switzerland.

This information has been prepared by WEDC Author: Sam Godfrey Series Editor: Bob Reed Design: Glenda McMahon Illustrations: Rod Shaw Graphics: Ken Chatterton Water, Engineering and Development Centre, Loughborough University, Leicestershire, UK. Phone: +44 1509 222885 Fax: +44 1509 211079 E-mail: WEDC@lboro.ac.uk Website: www.lboro.ac.uk/wedc

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Cleaning and disinfecting water storage tanks and tankers World Health Organization Introduction It is often necessary to quickly provide a basic water supply during and shortly after an emergency. This may be because the normal supply has been damaged or destroyed, or because people collect in a place where no water supply exists (a new refugee camp, for example). Often the quickest way of providing a water supply is to transport water in tankers from a nearby source and store the water in tanks and reservoirs. However it is rare for water tankers and reservoirs to be readily available in such situations. The most common solution is to hire vehicles and tanks that have been used for other purposes but they must be cleaned and disinfected before they can be used.

Large quantities of clean water will be required to clean and treat storage tanks and tankers before they can be used to store water.

Step 1: Cleaning the tank The tank must be cleaned to ensure that water stored in the tank does not become contaminated by dirt or traces of the substance the tank previously held. This can be achieved by following the three steps below: 1.

Drain/empty the tank. Open the outlet valve/tap and drain out any remaining liquid. Collect the liquids so that they can be safely disposed of. Most tankers have their outlet valve at the back, so park it on a slope so that all the liquids can be discharged (Figure 2). Permanent storage tanks are usually fitted with a washout valve that draws water from the base. Use this for emptying rather than the normal outlet valve. The process of emptying the remaining liquids from portable tanks will depend on the shape and design of the tank. Some can be tipped on their side and others dismantled.

Step 1: Clean the tank

Step 2: Chlorinate the tank

2. Step 3: Check chlorine residual

Figure 1. Steps for cleaning and disinfecting a water tanker

Steps of rehabilitation Figure 1 outlines a three step approach to cleaning and disinfecting water tanks and tankers. It is an emergency response to disinfect polluted or disused tankers so they can store and transport water of satisfactory quality.

Clean/scrub all internal surfaces. Use a mixture of detergent and water (household laundry soap powder will do) to clean all internal surfaces of the tank. This can be done with a stiff brush or a high pressure jet. If the tank has contained volatile substances such as oil or organic liquids such as milk, try not to enter the tank as the gases given off by the liquids could be dangerous. (See page 4 for health and safety advice.) Attaching the brush to a long pole may make it possible to clean the tank without entering it. Take special care to clean corners and joints so that no small amounts of the original liquid remain. Even minute amounts of some liquids can give the water a bad taste and people will refuse to drink it. Leave the outlet valve open whilst cleaning and collect the waste liquid for safe disposal.

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Water storage tanks and tankers 3.

Wash all internal surfaces to remove all traces of detergent. This is most easily done with a high pressure hose pipe or water jet but if they are not available the tank can be filled with water and left to stand for a few hours. Drain all the water from the tank and collect for safe disposal as before. Continue flushing the tank until there are no longer traces of detergent in the water.

Tank cleaning should be done in an open area away from houses to avoid possible health problems.

Cleaning the inside of the tank with a broom

Prepare a concentrated chlorine solution to disinfect the tank. The best source of chlorine to use is High Test Hypochlorite (HTH) granules or powder as this normally contains 50 to 70% chlorine. Box 1 outline methods for calculating the appropriate chlorine dose to disinfect a tank using HTH granules. Pour the solution slowly into the tank, mixing as you pour and then fill the tank up to full capacity with clean water. Let the chlorine stand in the tank for 24 hours to ensure that the tank is fully disinfected. If the tank has a cover (which is recommended) it should be closed. If the tank is required for use urgently double the quantity of chlorine added to the tank. This will reduce the standing time from 24 to 8 hours. Completely empty the tank and carefully dispose of the disinfecting water as it will contain a high concentration of chlorine. Remember to also clean and disinfect any pipes or hoses connected to the tank. Use the same procedure as described above.

Figure 2. Draining tanks

Step 2: Disinfecting the tank

To effectively disinfect the tank, fill it with clean water up to ¼ level only. It is important to not fill the tank too much as this will reduce the concentration of the chlorine solution and limit the effectiveness of cleaning. To estimate ¼ of the tank, use a stick with graded markers to indicate the water level. The markers should be marked on to the stick at 10cm intervals beginning at 0cm at the base of the tank and then upwards to 10, 20cm etc (Figure 4).

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Water storage tanks and tankers Disposal of waste liquids Box 1. Chlorine disinfection of a tank • • • Calculate the total volume of the tank. Fill a 20 litre bucket with clean water. Add 50g of HTH to the water and stir until dissolved. Add 10 litres (half a bucket) of the chlorine solution to the water in the tank for every cubic meter (m3) of tank volume. Remember 1m3 = 1000lt If there are large quantities of waste liquid, absorbing them into sand is not possible. In that case a vacuum tanker (such as one used for emptying septic tanks) will be needed to remove the liquid for safe disposal. If the tanker has been used for carrying other liquids, special arrangements must be made to prevent environmental pollution. One disposal option is to collect the waste liquid in a temporary pond and then mix the liquid with sand. The mix can then be transported to a suitable site (such as a land fill site) for disposal. Care must be taken when disposing of liquids from containers. Sudden discharge of water will cause localised erosion or flooding. Make sure the water is channelled into a natural water course such as a river, gully or lake.

•

Example The tank on a water truck needs to be disinfected. The tank is 4 meters long 1.8m wide and 1.4m high (the tank is oval shaped). The total volume of the tank is: ⎡ (1.4 + 1.8) ⎤ Π x x 4.0 = 8.04m 3 ⎢ ⎥ 2 ⎣ ⎦ 4 2

Therefore add slightly more than four, 20 litre buckets of chlorine solution as you fill the tank with clean water. A vacuum tanker

Stage 3: Chlorine testing

Refill the tank with clean water and allow to stand for 30 minutes. Test the residual chlorine left in the tank using a comparator. If the residual chlorine concentration is 0.5mg/l or less the tank is safe to use for water storage. If the concentration is greater than 0.5mg/l, empty the tank again and refill with clean water. Re-test to check that the chlorine concentration is 0.5mg/l or less.

The level of residual chlorine in mg of chlorine per litre of water (mg/l) is determined by dissolving a chlorine testing tablet in the water supply under test, in chamber (A). Compare the colour produced with the standard colours on the wall of chamber (B). A B C

1Dml Chlorine DPD colour 1.0 8.0 0.8 0.6 0.4 5.0 3.0 2.0

0.2 mg/l 1.5

Note: A third chamber (C) would be used if a higher chlorine residual is to be measured. A separate fact sheet is available on chlorine testing.

Figure 3. A chlorine comparator Hand-held comparator Page 11

Water storage tanks and tankers Health and safety issues Gaining access and working inside a water tanker can be difficult and dangerous. Frequently there is only a small access hatch on the top of the tanker through which to get in and out. Cleaners should be aware that some liquid carried in tankers can give off dangerous gases which may remain even when the liquid has been removed. The liquids may also cause physical dangers such as falling on slippery surfaces or burning from corrosive liquids. Always blow fresh air into the tank for a period before allowing a person to enter the tanker. The cleaner should wear protective clothing, including gloves, boots, a hat and glasses. Make sure someone remains outside, next to the access hatch all the time someone is working inside in case there is an accident. The availability of gas masks and portable ventilators would be an advantage.

Further information Davis, J. and Lambert, R. (2002) Engineering and Emergencies – A practical guide to fieldworkers, 2nd Edition, ITDG Publishing, UK.

World Health Organization WHO Headquarters Avenue Appia 20 1211 Geneva 27 Switzerland Telephone: Facsimile: Telex: Telegraph: (+ 41 22) 791 21 11 (+ 41 22) 791 3111 415 416 UNISANTE GENEVA

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Rehabilitating small-scale piped water distribution systems

This technical brief covers a process of rehabilitating small-scale piped water distribution systems (with pipe diameters up to 150mm) after natural disasters such as earthquakes, flooding, hurricanes, tornadoes, severe weather and fires. It does not cover disasters concerned with industrial pollution. This intervention aims at restoring supply to survival levels.

Step 1: Assessment and isolation Find out who manages the water distribution network, and identify local staff who understand the distribution system. These staff should participate in the rehabilitation. Inspect the distribution network as soon as possible. Assessment will be easier if there are updated drawings of the distribution network. Indentify:

Step 1 Assess damage, isolate affected area and inform consumers.

Number and location of visible breakage points Are the breakage points leaks, bursts, pipe fractures, pipe dislocations or complete pipeline section displacements? Proximity of the damage to the water source? Type of pipelines affected i.e. transmission mains, primary distribution mains, secondary distribution mains or tertiary distribution mains? Sizes and material of pipes affected? Extent of the affected area? Does it affect multiple supply zones? Is it possible to isolate the supply zones affected?

Step 2 Provide alternative supply to affected consumers.

Step 3 Isolate pipeline in sections and repair obvious leaks. Pressure-test the section. If leakage is higher than optimal value, repeat repair procedures.

Monitor the basic water quality parameters and feedback from consumers. Step 4 Clean and disinfect the repaired section.

The affected area(s) should be isolated from the rest of the distribution network. If flow control valves are not available, or cannot be traced, new valves should be installed. The affected consumers should be informed.

Step 5 Pressurise the section and test WQ. If WQ is bad, repeat cleaning and disinfenction procedures in Step 4. Otherwise commission section.

Step 2: Provide an alternative supply to affected consumers Establish what capacity of the system has remained intact and is able to provide emergency requirements. Assess emergency water requirements based on basic lifeline supply. Establish procedures for emergency treatment, pumping and distribution for service of emergency supply. For example, this could be achieved through:

Step 6 Carry out Steps 3 - 5 to all affected sections, starting with the section nearest the water source, and moving outwards.

Figure 1. Steps for cleaning and disinfecting a piped water distribution main in a post-disaster situation

provision of tankered water to various locations in the residential areas; using simple materials to construct emergency stand taps.

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Water distribution systems Step 3: Repair breakages From the assessment of the damage carried out in Step 1, determine and acquire the resources (manpower, equipment and materials) required for the repair work. Start at, or near, a source of supply and work outwards into the distribution system. Repair the pipeline in a stepped manner, one section after another. For example, referring to Figure 2, start with the section between SV1 and SV5, and move to the section between SV5 and SV6. Select a pipeline section that can easily be isolated by existing stop valves, of say 500m apart. The maximum length that can repaired, flushed and pressure-tested effectively is 1000m. Before starting any repair work: OPEN SHEATHING Walers

Open sheathing

Tight sheathing

Locate other underground utilities in the work area, and liase with their Maintenance Department, if necessary. As a safety precaution, find out what type of industries are nearby or which have ever used the site. If the soil is thought to contain hazardous wastes, the local responsible authority should be contacted for advice on further precautionary measures. Struts Walers

Struts

TIGHT SHEATHING

Isolate the section by shutting valves (such as SV1, SV2, SV3, WO1 and SV5 as shown in Figure 2) and close off all service connections. Arrange to install washout valves (such as WO1), and fire hydrants (such as FH1) if none can be traced in the selected section. Route traffic away from the work area. Service reservoir (if needed)

Figure 3. Types of shoring

Source or reservoir tank Main pipeline (transmission main Main pipeline Branch pipeline

Excavate and expose the leaking/broken pipelines, ensuring that the excavated soil is piled by the side of the trench with enough clearance for traffic, but far enough from the trench such that the repair crew can safely walk between the trench and the excavated material. Protect the repair crew from trenches collapsing in the course of repairs. This is achieved through trench shoring, as shown in Figure 3. The need for shoring depends on the following factors:

Branch pipeline SV2 SV1 FH1 SV3 B1 WO1 SV5 SV4

Service pipe B2 SC2

Branch pipeline KEY SV Stop valve B Breakage WO Wash-out valve

SC1 SV6

Depth and width of trench. Type of soil (clay, loam or sand). Soil conditions (compaction, moisture). Nearby activities that could cause vibration. Length of time excavation is expected to be open.

SC Boundary stop cock FH Fire hydrant

Use simple but effective methods of repair that will take the shortest time to restore services. Examples of simple methods:

Figure 2. Pipework making up a distribution system

The damaged section may be replaced by use of repair pipe clamps, as shown in Figure 4. Repair of cracks and breaks in steel pipes by welding.

Page 14

Water distribution systems Replace pipe support structures such as concrete anchorage and thrust blocks , if necessary. Backfill the excavation with select material, and compact as necessary, initially leaving the pipe joints exposed for water pressure testing. Fill the repaired pipeline section with water, and let it sit idle for at least 24 hours before the pressure test starts. Increase the pressure up to a level of at least 50% higher than the normal operating pressure, and maintain this for at least 4 hours. The leakage is determined by measuring the amount of water needed to refill the pipeline. However some leakage is expected. Table 1 shows a guideline of values of allowable leakage for pipes. Table 2. Velocity and flow required for flushing Pipe diameter(mm) 50 75 100 150 200 Velocity required (m/s) 1.3 1.6 1.8 2.2 2.6 Flow required (litres/sec) 2.7 7.2 15 41 83

Source: Institution of Water Engineers and Scientists, 1984

Examine the trench, and repair any joints if they show leakage. If the repaired pipeline has passed the pressure test, backfill the pipe joints, and proceed to clean and disinfect the pipeline section.

Step 4: Cleaning and disinfection Pipe flushing Isolate the section to be flushed from the rest of the system. Backfilling Confirm if quantity to flush the repaired pipeline has sufficient pressure and water in the system. Table 2 shows guidelines for adequate velocities and flow. If there is insufficient water additional pumps and storage tanks will be needed. Flush the section by opening the stop valve (SV1 on Figure 2) on the supply side slowly, and open the washout valve on the remote end (WO1). Inject the water through the pipe section continuously for a period long enough to stir up deposits inside the water main and wash out all silt (about 15 minutes). Direct flushing water away from traffic, pedestrians and private plots. Avoid erosion damage to streets, lawns and yards by use of tarpaulins and lead-off discharge devices. Avoid flooding which can cause traffic congestion. Collect two water samples from each flowing hydrant, one at the beginning (about 2 to 3 minutes after the hydrant was opened) and the second sample when the dirty water is assumed to be clean (just before closing the hydrant). Test the water quality to ascertain return to normality. If the water quality is not yet satisfactory, repeat the procedure. When the water quality has been restored to normal, slowly close the washout valve.

Figure 4. A pipe clamp

Table 1. Allowable leakage from pipes Pipe diameter(mm) Allowable leakage (litres per day per km) 166 249 332 498

50 75 100 150

Source: California State University, 1994

Page 15

Water distribution systems Pipe commissioning Calculate the volume of water in the pipeline section to be disinfected, as shown in Box 1. Acquire tanker(s) of volume equal to or higher than the calculated volume of the pipe. Box 1. Calculating the volume of water in a pipeline Example: Diameter of the pipeline is 100mm, and the section is 500 m long. The volume (V) of water in the pipe will be: V= π d2L/4 = 3.14*0.1*0.1*500/4 = 3.925 m3

Box 2. Preparing a chlorine solution Example: If we need 4000 litres of chlorine solution to fill the pipeline, we shall need (25 mg x 4000) = 100 grams of chlorine. If the source of chlorine is High Test Hypo chlorite (HTH) powder, with say a chlorine concentration of 50%, then we need: (100 g)/0.5 = 200 grams of HTH powder. Mix the water and the powder thoroughly, before use

A water tanker Prepare a chlorine solution of 25 mg/litre of free chlorine and mix it with clean water in the tanker (Box 2). Keeping the pipeline isolated, set up the feed tanker at the injection site (labelled as FH1 in Figure 2). Fill up the pipeline section with the chlorine solution. Keep the water in the pipeline for a minimum of 24 hours, during which time all valves and hydrants along the main should be operated to ensure their proper disinfection. Check the chlorine residual in the pipeline. If it has dropped significantly, repeat the disinfection procedure. Flush the pipeline section with clean water until a chlorine residual of 0.2-0.8 mg/litre is achieved. Reconnect the pipeline to the network and move onto the next section.

Further information California State University, Sacramento School of Engineering (1994), Water Distribution System Operation and Maintenance, 3rd ed., California State University, Sacramento Foundation, USA.

World Health Organization WHO Headquarters Avenue Appia 20 1211 Geneva 27 Switzerland Telephone: Facsimile: Telex: Telegraph: (+ 41 22) 791 21 11 (+ 41 22) 791 31 11 415 416 UNISANTE GENEVA

This information has been prepared by WEDC Author: Sam Kayaga Series Editor: Bob Reed Design: Glenda McMahon Illustrations: Rod Shaw Graphics: Ken Chatterton Water, Engineering and Development Centre, Loughborough University, Leicestershire, UK. Phone: +44 1509 222885 Fax: +44 1509 211079 E-mail: WEDC@lboro.ac.uk Website: www.lboro.ac.uk/wedc

Page 16

Emergency treatment of drinking water at point-of-use World Health Organization This note is about simple treatment of drinking water at point-of-use for people in, or just after an emergency. The options suggested are quick short-term measures to provide a safe survival level supply of drinking water from unsafe polluted water sources. The options should be sustainable until a longer-term safe and costeffective supply is available to the population. The methods described are suitable for water taken from any source but, in general, will only remove physical and microbiological pollution. Pollution by chemicals such as after a spillage of industrial waste will not normally be removed by these processes and specialist advice should be taken. In general terms, treatment of water at household level follows the processes shown in Figure1. However, depending on the quality of raw water, some processes may not be necessary. Such cloths remove organisms known as copepods, which act as intermediate hosts for the guinea-worm larvae. The cloth must always be used with the same surface uppermost. The cloth may be cleaned using soap and clean water.

Aeration Aeration is a treatment process in which water is brought into close contact with air for the primary purpose of increasing the oxygen content of the water. With increased oxygen content:

volatile substances such as hydrogen sulphide and methane which affect taste and odour are removed; carbon dioxide content of water is reduced; and dissolved minerals such as iron and manganese are oxidised so that they form precipitates, which can be removed by sedimentation and filtration.

Straining

The close contact between water and air required for aeration can be achieved in a number of ways. At a household level, rapidly shake a container part-full of

Storage/Settlement Raw water

Filtration

Aerator tray

Disinfection

Figure 1. General steps in the water treatment processes undertaken at household level Aerated water

Straining Pouring water through a clean piece of cotton cloth will remove a certain amount of the suspended silt and solids. It is important that the cloth used is clean, as dirty cloth may introduce additional pollutants. Specifically made monofilament filter cloths may be used in areas where guinea-worm disease is prevalent.

Figure 2. Aerator trays

Page 17

Emergency treatment of drinking water

2 3 1 (a) (b)

2 3 1

2 3

(c)

Drinking water: Always take from pot 3. This water has been stored for at least two days, and the quality has improved. Periodically this pot will be washed out and may be sterilized by scalding with boiling water. Each day when new water is brought to the house: (a) Slowly pour water stored in Pot 2 into Pot 3, wash out Pot 2. (b) Slowly pour water stored in Pot 1 into Pot 2, wash out Pot 1. (c) Pour water collected from the source (Bucket 4) into Pot 1. You may wish to strain it through a clean cloth. Using a flexible pipe to siphon water from one pot to another disturbs the sediment less than pouring.

Figure 3. The three pot treatment system water, for about five minutes and then stand the water for a further 30 minutes to allow any suspended particles to settle to the bottom. On a larger scale, aeration may be achieved by allowing water to trickle through one or more wellventilated, perforated trays containing small stones, as shown in Figure 2. Again, the water must be collected in a container and allowed to stand for about 30 minutes to settle suspended particles.

Simple up-flow sand filter Simple household filters may be put together inside clay, metal or plastic containers. The vessels are filled with layers of sand and gravel and pipework arranged to force the water to flow either upwards or downwards through the filter. Figure 4 shows a modified simple upward rapid flow filter. A filter such as this could be built from a 200 litre drum. It has a filter bed made up coarse sand (of about 0.3m depth) of grain size between 3 and 4mm diameter, and supported by gravel covered by a perforated metal tray. The effective filtration rate of such a filter could be as high as 230 litres per hour. Such filters must be dismantled regularly to clean the sand and gravel and remove any settled silt. The frequency of cleaning is dependant on the level of turbidity of the raw water. Furthermore, such filters are not effective at removing the pathogens. Therefore the water must be disinfected or stored for 48 hours in order to make it safe.

Storage and settlement When water is stored for a day in safe conditions, more than 50% of most bacteria die. Furthermore, during storage, the suspended solids and some of the pathogens will settle to the bottom of the container. The container used for storage and settlement should have a lid to avoid recontamination, but should have a neck wide enough to facilitate periodic cleaning. For example a bucket with a lid could be used for this purpose. Water should be drawn from the top of the container where it will be cleanest and contain less pathogens. Storage and settlement for at least 48 hours also eliminates organisms called the cercariae, which act as intermediate host in the life cycle of bilharziasis (schistosomoasis), a water-based disease prevalent in some countries. Longer periods of storage will leader to better water quality. A household can maximize the benefit of storage and settlement by using the three-pot system illustrated in Figure 3.

Charcoal filters Charcoal can be quite effective at removing some tastes, odours, and colour. Ordinary charcoal available locally could be used, but activated carbon is more effective, though rather expensive. An example of such a filter is the UNICEF upflow sand filter, illustrated in Figure 5. However, if the charcoal is not regularly renewed or if the filter is left unused for some time, there is evidence that it can become the breeding ground for harmful bacteria.

Filtration Filtration is the passage of polluted water through a porous medium (such as sand). The process uses the principle of natural cleansing of the soil.

Ceramic filters Water may be purified by allowing it to pass through a ceramic filter element. These are sometimes called candles. In this process, suspended particles are

Page 18

Emergency treatment of drinking water Inlet Cover Outlet

Water

300mm

Coarse Sand

mechanically filtered from the water. The filtered water must be boiled or otherwise disinfected. Some filters are impregnated with silver which acts as a disinfectant and kills bacteria, removing the need for boiling the water after filtration. Ceramic filters can be manufactured locally, but are also mass-produced. They can be costly but have a long storage life and so can be purchased and stored in preparation for future emergencies. The impurities held back by the candle surface need to be brushed off under running water, at regular intervals. In order to reduce frequent clogging, the inlet water should have a low turbidity. Figure 6 shows a variety of ceramic candles.

Drain stopper

Rocks

Perforated metal plate

Figure 4. A simple upflow rapid sand filter

Candle filters

Disinfection It is essential that drinking water be free of harmful organisms. Storage, sedimentation and filtration of water reduce the contents of harmful bacteria but none of them can guarantee the complete removal of germs. Disinfection is a treatment process that ensures drinking water is free from harmful organisms or pathogens. It is recommended that this be the final treatment stage, as many of the disinfection processes will be hampered by suspended solids and organic matter in the water. There are various methods of achieving disinfection at household level:

Figure 5. The Unicef upflow charcoal filter

(a) Manufactured unit

(b) Candle with jars

(d) Porous jar

Figure 6. Ceramic filters

Page 19

Emergency treatment of drinking water Disinfection by boiling Boiling is a very effective though energy consuming method to destroy various pathogens such as viruses, spores, cysts and worm eggs. The water should be brought to a rolling boil for at least five minutes and preferably up to a period of twenty minutes. Apart from the high energy costs involved in boiling, the other disadvantage is the change in taste of water due to the release of air from the water. The taste can be improved by vigorously stirring the water, or shaking the water in a sealed container after it has cooled. A better water quality can be obtained by storing the boiled water, as described earlier. solution, at the point of dispensing. See Note 1 Cleaning and Clear side of disinfecting wells for details of bottle facing sun preparing chlorine solutions.

Half blackened bottle

Solar disinfection Ultra-violent rays from the sun are used to inactivate and Ultra violet destroy pathogens present in radiation water. Fill transparent plastic containers with water and expose them to full sunlight for about five hours (or two consecutive days under 100% cloudy sky). Disinfection occurs by a combination of radiation and thermal treatment. If a water temperature of least 50oC is achieved, an exposure period of one hour is sufficient. Solar disinfection requires clear water to be effective. An enhanced example is the SODIS system, whereby half-blackened bottles are used to increase the heat gain, with the clear side of the bottle facing the sun, as shown above.

Disinfection using chlorine Chlorine is a chemical most widely used for the disinfection of drinking water because of its ease of use, ability to measure its effectiveness, availability and relatively lower cost. When used correctly, chlorine will kill all viruses and bacteria, but some species of protozoa and helmithes are resistant. There are several different sources of chlorine for home use; in liquid, powder and tablet form. Chlorine is commonly available to households as liquid bleach (sodium hypo chlorite), usually with a chlorine concentration of 1%. Liquid bleach is sold in bottles or sachets, available on a commercial basis. Chlorine must be added in sufficient quantities to destroy all the germs but not so much as to affect the taste adversely. The chemicals should also have sufficient contact time with the pathogens (at least 30 minutes for chlorine). Deciding on the right quantity can be difficult, as substances in the water will react with the disinfectant at different rates. Furthermore, the strength of the disinfectant may decline with time depending on how it is stored. It is therefore recommended that in emergency situations, chlorine solutions be centrally dispensed to the users by qualified personnel. Displaced people should receive standard containers for collecting/storing water, as well as simple dropper tubes or syringes. Technical staff should provide the instructions for mixing the chlorine

Other water treatment chemicals A number of commercially produced chemicals have been developed to holistically treat water at household level in emergency situations. Studies have shown that some of these powders significantly remove pathogenic bacteria, viruses and parasites from water. They also enable the particles to flocculate together, so they then to sink to the bottom of the container. Commercially available sachets typically treat 10 litres of water. The water should be allowed to stand for at least 5 minutes before it is strained. It should be allowed to stand for a further 30 minutes before it is used for human consumption.

Further information Shaw, Rod (ed.) (1999) Running Water: More technical briefs on health, water and sanitation, ITDG, UK.

Page 20

Rehabilitating water treatment works after an emergency World Health Organization In urban areas, the population may be entirely reliant on the public water supply system for their drinking water. Modern water treatment works (WTWs) rely on inputs of chemicals, electricity and skilled operators as well as the constructed plant and machinery. Clean water then needs to be delivered but piped systems can be prone to leaks, intermittent operation and contamination. Managing a water supply system is a complicated task and it is strongly recommended that a suitably qualified engineer is responsible for the rehabilitation of any system. Service reservoir (if needed) Branch pipeline Main pipeline Branch pipeline Service pipe Standpost Yard tap Source or Reservoir tank Main pipeline (transmission main) Branch pipeline Service pipe

House connection

Collecting basic information

Find out who runs the water system – operators and managers. How does the system work? What is not working?

Service pipe

Figure 2. A distribution network Identifying local WTW operators who understand the system is a priority; this will provide knowledge (of the works and sources of supplies) and a skilled work force. Efforts should be made at an early stage to find, recruit and pay the operators and managers. Water source

In order to repair a water supply it is important to understand how the system works. Individual WTWs will vary in design, but most are based on a variety of basic components that fit together. These improve the quality of water in stages The condition of each component needs to be assessed. Repair and renovation are faster than replacement because any existing staff will know how to use existing plant and finding replacement parts is generally quicker than building a new unit. Distribution systems are based on a series of large (trunk) water mains that feed into smaller pipes. Concentrate on trunk mains before moving onto local distribution networks. Reservoirs are needed at various points in the system to ensure continuous supplies of water. Both pipes and reservoirs need to be physically undamaged and clean.

Power

Drinking water

Water treatment works Staff Chemicals

Setting priorities

Provide a basic supply Identify risks of contamination Improve quality in stages

Figure 1. WTW requirements

Page 21

Rehabilitating water treatment works Distribution first The first requirement is to get water into the distribution system, with only enough treatment to ensure that the water is free of gross contaminants that may block or damage the pipes and pumps used. The order of rehabilitation should be: 1. 2. 3. 4. 5. Intake Pumps and trunk water mains Local distribution pipes Storage reservoirs Water treatment

Risk assessment There are many chances for water to become recontaminated once it leaves the WTW (such as improper handling or pollution through leaking pipes) so investments in water quality improvements need to be assessed by looking at the whole system and seeing the impact at the point of use. If water in the distribution system cannot be guaranteed to stay clean, it may be better to supply some users (such as hospitals) with water in a tanker, that can be disinfected and the quality maintained. Simple treatment can be provided at a more local level, such as chlorinating local water storage tanks. Pumps may be used at various stages, such as pumping water from the intake to the WTW or from the WTW to the distribution system. In some cases the water can flow for all or part of its way through the WTW under gravity. Replacement parts may take time to be delivered, so ask an engineer to make an early assessment of the state of the pumps. Power for pumps should be given priority over every other use – even over hospitals.

This may involve by-passing all or part of the WTW. Initially water may be pumped directly from the source into the distribution system, without any treatment apart from the intake screens or simple sedimentation without chemicals. Storage in service reservoirs is important as it can ensure a continuous supply – intermittent supply can lead to contamination of water in the pipes and deprive people at the end of the pipes of water.

Checking for leaks Reducing leakage can improve both the quantity and quality of water available to the public, but the distribution system is difficult to assess because it will be buried and spread out over the whole urban area. Repair obvious leaks first as they are likely to be the largest. Ask the public to report problems and sightings of leaks and puddles. Offer a small reward for information – this will be cost effective as it will quickly identify problem areas in the distribution network. Meters and pressure tests may also identify leaks and broken pipes.

Delivery Power unit Flexible flange coupling

Pump

WLIC1111

Suction

Figure 3. Centrifugal pump driven by a shaft connection

Providing treatment in stages The order of water treatment is important – for example coarse filtration needs to take place before finer filtration and chlorination needs to take place only once the water is physically clean and there is little chance of re-contamination during delivery or use. The order of WTW rehabilitation activities should be: 1. 2. Water distribution is the first priority 3. 4. Page 22

Source protection (preventing pollution in the first place) Physical treatment (screening, aeration, settlement, filtration) Chemical treatment (coagulation, pH correction) Disinfection (chlorination)

Rehabilitating water treatment works River source Intake Screen Delivery pipe network Water storage Excreta,solid waste and stormwater

Sedimentation

Filtration

Agricultural pollution and soil erosion

Chemical pollution

Figure 5. Preventing pollution upstream reduces the need for treatment Coagulation Chlorination

Power can be supplied by mobile generators if mains supplies are not available or unreliable. Maintenance: This includes manual tasks, such as cleaning screens, removing settled sludge and lubricating pumps The filters will begin to get clogged with solids. Pipes need to be checked for leaks.

Figure 4. Treatment in stages

Repairs, restoration and operation The damage to a water supply system will vary according to the cause of the emergency. Floods may inundate and pollute the whole system, necessitating cleaning of the whole WTW and piped system and repairing or replacing electrical equipment. Damage to the electric motors for water pumps are a main cause of failure of the whole system. Earthquakes or landslides may leave machinery unharmed but break pipes or tanks. War or civil unrest may lead to looting or wanton damage, especially to mechanical and electrical plant. Any precarious situation may disrupt inputs of chemicals, electricity and technical expertise. Once part of the WTW has been re-commissioned, it will need to be operated. Other tasks include measuring the quality of the water to ensure that the WTW is being operated efficiently. Spare parts, water quality testing kits and other consumables will all be required.

Other actions

Pollution prevention: A more effective way of increasing the quality of water may be to reduce the need for treatment in the first place. Preventing pollution from occurring in the first place by providing environmental sanitation (management and disposal of excreta, solid waste and rainwater), controlling erosion and restricting public access to the catchment of the water source can reduce the amount of contaminants that have to be removed from the water. Restoring sewage collection and treatment may be more important than a complete WTW. Public information: The public should be kept informed of developments in the availability and quality of water. They can help in reducing wastage and identifying leaks in the distribution system.

Chemicals: Modern WTW rely on the addition of chemicals to aid the treatment process. These include alum to help settlement, lime for adjusting the pH of the water and chlorine for disinfection. There may be a long time delay in gaining new supplies so the need for chemicals should be identified and suppliers contacted. A reduced level of treatment can be provided if chemicals are in short supply, using what materials are available where they are most needed (e.g. for disinfecting water supplies to hospitals).

Further information Twort, A.C. et al. (2000) Water Supply, 5th ed. Arnold with IWA Publishing: London

Page 23

Rehabilitating water treatment works Source: Water may be from surface water (river or lake) or groundwater. Prevent pollution to reduce the amount of treatment needed later. Intake: Some simple treatment may take place at the intake, such as a coarse screen or aeration. Storage at this stage allows some solids to settle out before treatment and provides a limited reservoir of water if the source fails (e.g. an oil spill in a river). Settlement/clarification: If the water is stored for a while, solids will fall to the botton of the tank and scum will float to the surface. This process can be enhanced by mixing a coagulant into the water (such as alum), to make small solids stick together (flocculate) and settle faster. Water can either slowly flow horizontally through a tank or vertically, with the sediment forming a horizontal suspended layer. Filtration: Various types of filters may be used: Roughing filters have a coarse media, and actually promote settlement as well as filtration within the media. They are used for treatment early in the WTW. Rapid gravity filters are a standard method of treating water. Settled water is passed through a layer of coarse sand to remove silt. Direct filtration is rapid filtration without any settlement stage before it. These filters require backwashing frequently. Pressure filters operate in an enclosed vessel under pressure. This reduces the need for pumping in some circumstances, but requires careful operation. Slow sand filters have a fine sand media and can also reduce pathogens. They are simple to use. Membranes are complex to operate but can provide a high quality level of treatment. Disinfection: Adding chlorine to the water not only kills many pathogens, but also provides a level of protection from recontamination in the distribution system. Complex chlorine dosing systems use chlorine gas, but liquid or solid chlorine compounds are also available and can be used manually. The treated water needs to be stored for a while to allow the chemical to work. The effectiveness of chlorination is reduced for water that is dirty or will be re-contaminated, so priority should be given to cleaning the water and ensuring it stays clean before disinfecting it. Treated water storage: The supply and demand for water varies throughout the day; to cater for this variation, a tank is used. This also provides water for use in emergencies - such as for fire fighting or for short breakdowns in the WTW. Distribution: Once the WTW is producing water, this can then be distributed to the population. Tankers may be used if the piped system is out of use. Feed Sedimentation

Pump to next stage?

Intake with screen

Sludge bleed Pump to next stage?

Effluent

Sludge blanket

Sludge Filtration

Drain

Filtrate Sand Pump to next stage? Gravel

Control guage

Chemical

Pump Disinfection

Water level rises and falls during day Storage

Figure 6. A water supply system at a glance

This information has been prepared by WEDC Author: Brian Reed Series Editor: Bob Reed Design: Glenda McMahon Illustrations: Rod Shaw Graphics: Ken Chatterton Water, Engineering and Development Centre, Loughborough University, Leicestershire, UK. Phone: +44 1509 222885 Fax: +44 1509 211079 E-mail: WEDC@lboro.ac.uk Website: www.lboro.ac.uk/wedc

Page 24

Solid waste management in emergencies World Health Organization This technical note outlines some of the key activities in dealing with solid waste in the immediate aftermath of a disaster. Solid waste refers here to all non-liquid wastes (e.g. rubbish or garbage). Sometimes solid waste may contain faeces. Solid waste can create significant health problems and a very unpleasant living environment if not disposed of safely and appropriately. It can provide breeding sites for insects and vermin (e.g. rats) which increase the likelihood of disease transmission, and can attract snakes and other pests. Unmanaged waste can also pollute water sources and the environment. The process of planning solid waste management in an emergency is illustrated in Figure 1.

What opportunities or restrictions does the environment present? Is it possible to dig pits? Where are surface water sources located? At what level does the water table like? Where is land available?

The waste

What waste is being generated (e.g. organic, hazardous, dry etc.)? Where is waste being generated? How accessible are waste generators? How much waste is being generated?

Initial assessment The first stage in dealing with solid waste is to understand the emergency context and the nature of waste being generated. The following sections outline key questions for consideration.

Please note: Medical and hazardous wastes are not discussed in this technical note.

Initial assessment Understanding the context and waste generation.

The context

What solid waste management systems/ equipment is already in place? How has it been affected? Is it possible to work with and learn from the existing systems? How many people are affected? Where are they? What are they doing with waste at present? Are there any pertinent cultural factors? Immediate response (1 month) Clearing scattered waste and introducing onsite and community pits.

Waste generation, density and sources Waste is produced by households, shops, markets, businesses, medical centres and distribution points. Generation rates vary considerably according to seasons, diets (e.g. changes from fresh vegetable to packaged aid goods) and even the day of the week. An average of around 0.5kg/ capita/ day is common in low-income cities. Waste densities also vary considerably. Densities for low-income cities are usually around 200-400 kg/m3. Where lots of packaging is used in emergency situations, densities are likely to decrease.

Intermediate response (6 months) Developing collection and disposal system and building landfill pits away from settlements. Consulting and educating users.

Long term solutions (Not covered in this technical note).

Figure 1. The process of planning solid waste management in an emergency

Page 25

Solid waste management Immediate response Activities should be prioritised according to present and future health hazards of different waste types and sources. Activities are likely to focus on clearing of existing scattered waste and managing waste from households and markets.

Intermediate solutions Community issues Consultation. It is useful and important to consult potential users of a waste management system before and during design and implementation. Education. It is important for participating communities to understand how good solid waste management can be achieved and can benefit their health.

On-site household disposal Suitable where space is not too limited and where waste has a high organic content (as it will decompose and reduce in volume). Also useful in areas where access is difficult. Pits should be 1m deep and be frequently covered with ash/soil to prevent access to waste by insects and rats, and to reduce odours. Note that on-site disposal is labour-intensive and requires advanced household cooperation.

Collection and storage In some situations on-site, community pits may be a suitable medium-term solution, whilst in others it will be necessary to devise ways of removing and disposing of waste. This will usually involve the following:

storage in the house; deposition at intermediate storage point; and collection and transport to final disposal.

Community pits Must be located within 100m walking distance of any household (SPHERE Guidelines). As a rough guide guide, 50 people will fill 1m3 of a pit each month, depending on generation rates and density. These are rapid to implement and requires little operation and maintenance. Note that some people may object to walking 100m to deposit waste.

In the home, plastic bags or a small container with a lid make suitable storage containers.

For intermediate storage points in communal areas bins of maximum 100 litre capacity are required (when full this will weigh around 40kg). Oil drums cut in half can be suitable. Ideally the bin will be arranged so that it can be emptied easily (e.g. hinged so it can tip into a handcart). A 100 litre bin is required for each 50 people or for a few market stalls. Bins require daily emptying, and this is labour-intensive. Page 26

Solid waste management Transport When selecting suitable vehicles, waste generation rates and densities need to be considered along with:

areas they need to access (e.g. narrow alleys or uneven paths); and distance between collection and disposal points.

For example, a wheelbarrow could collect waste from approximately 50 individuals before requiring emptying.

Page 27

Solid waste management Disposal As a medium-term solution, larger-scale landfill pits can be constructed. Without leachate (liquid runoff) treatment these are not suitable for long-term use. They should be situated at least1km downwind of settlements, at a location selected in consultation with the population. They should also be situated downhill of water sources and at least 50m from surface water sources. Carefully consider drainage where the pit is on sloping ground and erect fences to keep animals and scavengers out.

Recycling and composting In time it may be possible to work with local recycling industries to encourage entrepreneurs or waste collectors to gather recyclable items. This can provide a source of income as well as reducing the amount of waste requiring disposal. Home composting can also be an effective means by which to reduce the volume of waste requiring collection and disposal.

Management and implementation It is important to consider management structures and implementation methods. At times in emergency situations, particularly early on, activities may have to be strongly enforced until more participating systems can be introduced. Continuously review, monitor and response to the nature of waste, pervading conditions and levels of community participation.

Staff Approximately 2.5 workers are required for 1000 community members (WHO/ UNEP 1991). Protective clothing and equipment need to be considered (e.g. gloves, boots, visibility jackets).

Other important factors Incineration Incineration is not usually a favourable option for solid waste management as it requires a large capital input and care for operation and management to ensure nonpolluting bone. Where burning is deemed necessary (e.g. to reduce waste volume), it must be done at least 1km downwind of settlements, and ashes should be covered with soil daily. On-site burning of household waste can be highly-polluting and can be a fire hazard.

Long-term waste management In the long-term, capacity of landfill sites need to be increased, leachate needs to be contained and treated and the overall sustainability of waste management practices must be considered. Long-term solutions are beyond the scope of this technical note.

Further information Harvey, P., Baghri, S and Reed, R. A. (2002) Emergency Sanitation: Assessment and Programme Design. WEDC, Loughborough, UK SPHERE Guidelines, The Sphere Project (2004) Humanitarian Charter and Minimum Standards in Disaster Response, The Sphere Project: Geneva, Switzerland (Distributed worldwide by Oxfam GB) http://www.sphereproject.org/ handbook/index.htm

Care of equipment Waste can often be corrosive, so it is important to paint all metal waste management equipment and to wash it frequently. Such activity can significantly increased the life of equipment.

Emergency response waste Packaging of emergency response provisions (e.g. food, water, medicine, shelter) can produce serious waste problems. Consider this in procurement and where possible manage packaging waste at point of distribution to prevent its widespread scattering.

This information has been prepared by WEDC Author: Jonathan Rouse Series Editor: Bob Reed Design: Glenda McMahon Illustrations: Rod Shaw Graphics: Ken Chatterton Water, Engineering and Development Centre, Loughborough University, Leicestershire, UK. Phone: +44 1509 222885 Fax: +44 1509 211079 E-mail: WEDC@lboro.ac.uk Website: www.lboro.ac.uk/wedc

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Disposal of dead bodies in emergency conditions World Health Organization This technical note provides guidance on the disposal of dead bodies in emergency situations. Where there are many fatalities, the collection and disposal of bodies becomes an urgent need. This is not usually due to any health-related risks, which are likely to be negligible, but is important because of the possible social and political impact and trauma. So emergency relief teams should primarily be concerned with the mental health of the community and its need to carry out the cultural obligations and traditions to take care of the dead, rather than potential disease transmission.

Mental health risks The psychological trauma of losing loved ones and witnessing death on a large scale is the greatest cause for concern. It is therefore, important to collect corpses as quickly as possible to minimise this distress. It is, however, not necessary to rush their burial or cremation. This does not allow for the correct identification and record taking of the details of the dead. Nor does it give the time for the bereaved to carry out the ceremonial and cultural practices, which would normally occur after a death.

Physical health risks The widespread belief that corpses pose a risk of communicable disease is wrong. Especially if death resulted from trauma, bodies are quite unlikely to cause outbreaks of diseases such as typhoid fever, cholera, or plague, though they may transmit gastroenteritis or food poisoning syndrome to survivors if they contaminate streams, wells, or other water sources. Cultural and religious practice Relief workers should respect the wishes of the families and communities of the dead to observe whatever cultural and religious events are usually practised on death. This is important in helping people deal with the psychological impact of such disasters. Encouraging stricken communities to carry out traditional ceremonies and grieving processes sets in motion the process of disaster recovery.

Recovery of bodies To minimise the distress caused by the sight of dead bodies and the odours produced by their decomposition, it is important to collect and remove corpses to a collection point as quickly as possible. Anyone in charge of a body recovery team should be aware of the stress and trauma that team members might feel, and provide support for this where possible.

Mortuary services It is important to provide secure morgue facilities where there are casualties following an emergency, where there is an epidemic, or if burial or cremation are likely to be delayed. A temporary mortuary site should consist of a reception, a viewing room, a storage chamber for bodies not suitable for viewing and a room to store personal possessions and records. The recommended capacity for a field morgue is 10 bodies per 10,000 population. Bodies should be stored at 4ºC,

A mass grave

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Disposal of dead bodies although this is rarely possible. Mortuary staff should wear gloves and protective clothing and should wash with disinfectant soap. A complete list of mortuary requirements is given below. Where this is not possible, the minimum facilities are stretchers, leather gloves, rubber gloves, overalls, boots, caps, soap, disinfectants and cotton cloth. Following an emergency, when the decision is made to close a temporary mortuary, appropriate cleansing of the site should take place. Displaying bodies for identification needs space; 1000 bodies require over 2000m2. Identification can be a lengthy process, especially where no personal documentation is carried. When relatives and friends of the dead are involved, it must be remembered that visual identification is not scientific. In emergency situations, this process is even more difficult as it may be necessary for relatives to view numerous bodies in the hope that they will make an identification. This would normally be avoided. Where possible, it is important to differentiate viewing a body for identification from viewing a body for grieving purposes and separate locations should be provided. Once identified, a death certificate should be issued, an official record of death prepared and the body tagged. With violent deaths, it is also important to record the cause of death for possible future investigation.

Equipment for mortuary services in major disasters • Stainless steel postmortem tables or heavy duty trestle tables covered with plastic sheeting. Wheeled trolleys for transporting bodies within the mortuary. Tarpaulin or plastic sheeting for the floor, if it is not made of concrete. Heavy-duty black plastic sheeting for temporary screens. Refuse bins and bags. Cleaning materials – mops, buckets, cloths, soap, towels. Disinfectant and deodorizer. Protective clothing and heavy-duty rubber gloves. Translucent plastic body bags 0.1 mm thick and labels (if epidemic circumstances). Wall charts to record progress or large poster boards if there are no walls.

•

Body disposal Burials in common graves and mass cremations are rarely warranted and should be avoided.

•

• •

Burial Burial is the preferred method of body disposal in emergency situations unless there are cultural and religious observances which prohibit it. The location of graveyards should be agreed with the community and attention should be given to ground conditions, proximity to groundwater drinking sources (which should be a least 50m) and to the nearest habitat (500m). An area of at least 1500m2 per 10,000 population is required. The burial site can be divided to accommodate different religious groups if necessary. Burial depth should be at least 1.5m above the groundwater table, with at least a 1m covering of soil. Burial in individual graves is preferred and can be dug manually. If coffins are not available, corpses should be wrapped in plastic sheeting to keep the remains speparate from the soil. Burial procedures should be consistent with the usual practices of the community concerned.

• •

•

Revised list taken from Clark, Nicholls and Gillespie (1992), cited in Wisner and Adams (2002).

Identification of bodies One of the major challenges of effective management of dead bodies is their early identification and tagging. Records of deaths and funerals need to be kept to monitor mortality rates and the incidence of disease and to be able to provide timely, understandable and accurate information to relatives of the dead.

Cremation There are no health advantages of cremation over burial but some communities may prefer it for religious or cultural reasons. Factors against it are the amount of fuel required by a single cremation (approx 300kg. wood) and the smoke pollution caused. For this reason,

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Disposal of dead bodies cremation sites should be located at least 500m downwind of dwellings. The resultant ashes should be disposed of according to the cultural and religious practice of the community.

Cholera Contact with the body leads to exposure to cholera vibrios and requires careful washing using soap and water.

Action in medical epidemics Where possible, in the case of a medical epidemic, body handling should be left to specialist medical staff. Rather than using lime for disinfection purposes, which has a limited effect on infectious pathogens, it is better to use chlorine solution or other medical disinfectants. Any vehicles used to transport bodies to burial or cremation sites during epidemics should also be disinfected after use. It is important to make communities aware of the risks of contagion from practices such as traditional washing of the dead. Also, any large gathering, including a funeral, can be a way of spreading an epidemic. Consequently, burial or cremation should take place soon after death at a site near the place of death with limits placed on the size of any gathering.

Ebola Ebola is spread through bodily secretions such as blood, saliva, vomit, urine and stools, but can easily be killed with soap and water. Those dealing with the disposal of bodies require high levels of protection.

Typhus and plague To avoid infestation with the fleas and lice that spread these diseases, protective clothing should be worn. Body bags should be used to store the bodies prior to burial or cremation.

WP V12

Road V16 Scrub woodland/ small-scale farming BG V14 Dispensary Buffer zone

KEY: BG Burial ground Cholero centre Health post

V11 WP V10 SCH

V15

CC HP

SCH School WP Swampy ground V1 Water points Village 1

V13

2.6km

BG V4 WP V3 V2 Compound entrance SCH V1 WP V5 WP HP Market 1 1.3km V8 WP

V20

V18 V6

V22 WP

V30 SCH V29

Buffer zone

V19

V23

V31

V33

V17 WP V24 WP V25 1.2km

V21

IFRC compound Food distribution centre

V26 Market 2

V27

WP 1.2km

V28

Figure 1. Location of burial ground

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Disposal of dead bodies Important principles • • Give priority to the living over the dead. Dispel myths about health risks posed by corpses. Identify and tag corpses. Provide appropriate mortuary services. Reject unceremonious and mass disposal of unidentified corpses. Volunteers remove bodies with extreme caution • • • Respond to the wishes of the family. Respect cultural and religious observances. Protect communities from the transmission of medical epidemics.

• • •

Further information Harvey, P., Baghri, S. and Reed, R.A. (2002) Emergency Sanitation, Assessment and Programme Design. WEDC, Loughborough, UK. Davis, J. and Lambert, R. (2002) Engineering in Emergencies: a Practical Guide for Relief Workers, (2nd. Edn.) ITDG Publishing, London. Wisner, B. and Adams, J. (eds.) (2002) Environmental Health in Emergencies and Disasters. WHO, Geneva. Pan American Health Organization (PAHO) (2003) ‘Unseating the Myths Surrounding the Management of Cadavers’, Disaster newsletter, No. 93, October 2003. PAHO, USA.

This information has been prepared by WEDC Author: Julie Fisher Series Editor: Bob Reed Design: Glenda McMahon Illustrations: Rod Shaw Graphics: Ken Chatterton Water, Engineering and Development Centre, Loughborough University, Leicestershire, UK. Phone: +44 1509 222885 Fax: +44 1509 211079 E-mail: WEDC@lboro.ac.uk Website: www.lboro.ac.uk/wedc

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Minimum water quantity needed for domestic use in emergencies World Health Organization How much water is needed? A water supply is an essential requirement for all people. Determining how much is needed is one of the first steps in providing that supply. Providing enough water to meet everybody’s needs may be difficult in the short-term so water can be made available in stages. Continuous checking – including talking to the various users of the supply (especially women) will enable limited resources to be focused effectively. Providing water is never free; the water needs to be collected, stored, treated and distributed. Providing too much water is a waste of money. Taking too much water from a limited source may deprive people elsewhere of water and have adverse environmental and health impacts.

How much does each individual use? People use water for a wide variety of activities. Some of these are more important than others, for example, having a few litres of water to drink a day is more vital than washing clothes - but people will need to wash if skin diseases are to be prevented and physiological needs met. Each additional use has health and other benefits, but with decreasing urgency (see Figure 1). This is often measured in litres per person (capita) per day (Lpcd).

Collect basic information

How many people are there? How much does each individual use?

A hierarchy of water requirements People’s needs are not always predictable. For example, the need to wash sanitary towels or to wash hands and feet before prayer may be felt to be more important than other uses. Talk to people to confirm their priorities. Different populations may also have specific needs such as using water for anal cleansing. Different genders will also have different priorities, with women being concerned about basic household needs at the top of the hierarchy, men perhaps having a concern for livestock, girls needing water to wash during menstruation and boys wanting to go for a swim! Waste, spillage and leaks also need to be taken into consideration. Hot or windy weather may increase people’s individual needs. To establish how much an individual needs, standard quantities have been established as guidelines (see Table 1). These have been broken down into categories to increase the accuracy of the estimate. For example, not all water will be needed at the house. It may be preferable to provide separate water supplies for bathing, washing or animals, as well as for hospitals, feeding centres and schools. Water for hand washing will be needed near latrines.

How many people are there? Establishing the population to be supplied may not be easy after an emergency, but consulting administrators, feeding centres, community leaders and making direct observations (such as the average number of people per shelter and then counting shelters) can give various estimates of the population. Don’t just rely on one figure but compare independent assessments. Displaced people will also be moving about, so estimate changes in population. Include local populations as well as displaced people.

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Minimum water quantity needed

10L 20L 30L 40L 50L 60L 70L

drinking cooking personal washing washing clothes cleaning home

growing food (domestic use) waste disposal (sanitation) business (crops production livestock) gardens recreation

Figure 1. Hierarchy of water requirements (after Abraham Maslow’s (1908-1970) hierarchy of needs)

Water does not all have to come from the same source. People may be provided with bottled drinking water, but use a stream to wash their clothes in. As demand for water increases, generally the quality needed for each use can be reduced. Water for cleaning a floor does not have to be of drinking water standard and water for growing subsistence crops can be of a lower quality still. Before the quantity of water can be established, decisions need to be made.

Managing demands It may be that some water demands can be reduced by providing alternatives. Flush toilets (water borne sanitation) require a large volume of water (up to 70L per person per day). Pit latrines or simple pour-flush toilets should be the first choice. Some water requirements may be met by using lower quality (untreated) water or by recycling water. Encouraging drought resistant crops or keeping livestock that can survive on less water can reduce demands, as can providing alternative livelihoods that require less water.

Ensuring supply has an impact Supplying water does not mean it is all having the desired impact. Look at the whole water supply system and identify weak points. Providing more water to a tap stand will not necessarily increase consumption if it is too far away or people do not have enough water containers. Providing more water may cause drainage problems if there are no facilities for disposing of sullage.

Decide:

what needs are going to be catered for; (e.g. only drinking or drinking, cooking and washing) what is the programme for implementation; (e.g. provide limited water initially and a full supply later) what sources are available; (e.g. are resources limited, what is the water quality) and who is managing each supply (e.g. which organisation is responsible for domestic supplies, hospital supplies, needs of schools).

Evaluate

See how much water people are actually using. When and where are they using it?

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Long term – lasting solution Generally: Increasing quantity Decreasing quality

Medium term - maintaining

Short term -survival

Minimum water quantity needed Table 1. Some standard water requirements Standard: All people have safe access to a sufficient quantity of water for drinking, cooking and personal and domestic hygiene. Public water points are sufficiently close to shelters to allow use of the minimum water requirement. Key indicators At least 15 Lpcd is collected. • Flow at each water collection point is at least 0.125 litres per second. • There is at least 1 water point per 250 people. • The maximum distance from any shelter to the nearest water point is 500 metres. Guidelines Individuals Minimum ‘survival’ allocation: 7 Lpcd (sustainable for only a few days) • Drinking: 3-4 Lpcd • Food preparation, cleanup: 2-3 Lpcd Medium term allocation: 15-20 Lpcd (sustainable for a few months) • Drinking: 3-4 Lpcd • Food preparation, cleanup: 2-3 Lpcd • Personal hygiene: 6-7 Lpcd • Laundry: 4-6 Lpcd

Figure 3. Typical relationship between water collection journey time and domestic consumption (after Cairncross & Feachem 1993)

Table 2. Water collection standards Two vessels 10-20L for collecting water plus one 20L vessel for water storage, (narrow necks and covers) per 5 person household.

Other needs • Health Centres: 5 litres per out-patient; 40-60 litres per In-patient • Hospital (with laundry facilities): 220-300 litres per bed • Schools: 2 litres per student; (10-15 litres per student if water-flushed toilets). • Feeding Centres: 20-30 litres per patient • Camp Administration: (Staff accommodation not included) 5 Lpcd • Staff accommodation: 30 Lpcd • Mosques: 5 litres per visitor • Sanitation (hand-washing, cleaning latrines etc.): depends on technology. Livestock and agriculture • Cattle, horses, mules: 20-30 litres per head • Goats, sheep, pigs: 10-20 litres per head • Chickens: 10-20 litres per 100 • Vegetable gardens: 3-6 litres per square metre Actual values depend on many variables (such as cultural practices and climate) that should be assessed by specialists

What happens to waste water? Simply supplying as much water as possible is not the best solution. Once more than the basic quantity is available, any additional water will eventually need to be disposed of (spillages, sullage or wastewater). The costs of supplying water will therefore need to take the costs of disposing of this used water safely. Some water can be re-cycled, reducing the need for both supplying and disposing of water - for example using sullage and spilled water from washing facilities can be used to grow crops.

Further information The Sphere Project (2004) Humanitarian charter and minimum standards in disaster response. The Sphere Project: Geneva, Switzerland. http://www.sphereproject.org U.S. Agency for International Development, Bureau for Humanitarian Response, Office of Foreign Disaster Assistance (OFDA) (1998) Field operations guide for disaster assessment and response. http:// www.usaid.gov/our_work/humanitarian_assistance/ disaster_assistance/resources/index.html#fog House, Sarah and Reed, Bob (2000) Emergency water sources: Guidelines for selection and treatment WEDC, Loughborough University, UK. http://wedc.lboro.ac.uk/publications/

From the water point to the home Even if plenty of water is provided, there may be other limits to its use, such as the time taken for people to travel and queue to get it. If people take more than 30 minutes to collect water, the amount they will collect will reduce (see Figure 3). The amount of storage facilities available is also important (see Table 2). Washing facilities near the water points reduce the need to transport water.

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Minimum water quantity needed A sample calculation How much water is needed for a refugee camp for 5,000 displaced people (including 2000 school age children), 25 relief agency staff, and 75 cows? Decisions • Water for crops will not be provided • Water for livestock will rely on a river • Water for the hospital is the responsibility of another agency and will be a separate supply system. A feeding centre, however, will be supplied with water. • Staff will be resident during the initial stages but will be able to travel into the camp at a later date and are not included in that calculation • Assume 10% wastage (from spills, leaks, waste) • School will not be operational until after phase 1 and will not have flush toilets • Assume some further population movement Phase 1 - an emergency supply Domestic use: 5000 x 7 litres Feeding centre: 5000 x 20 litres Staff centre: 25 x (5 + 30) litres Total

= = = =

≈ Phase 2 - a long-term solution Domestic use: 4500 x 20 litres Feeding centre: 1000 x 30 litres Staff centre: 25 x 5 litres School: 2000 x 2 litres Total = = = = =

35,000L (7 Lpcd) 100,000 L (20 Lpcd) 875 L (5 Lcpd for office plus 30 Lcpd for accommodation) 135,875 L plus 10% leakage 150,000 litres per day

≈

90,000 L (planned decrease in population, but increase allowance to 20 Lpcd) 30,000 L (feeding vulnerable groups only but providing 30 Lpcd) 125 L (staff no-longer resident) 4,000 L (2L per pupil) 124,125 L plus 10% leakage 137,000 litres per day

Evaluate Long term treatment facilities limited due to difficulties in importing chemicals, so reduce domestic demand by providing washing facilities using partially treated water.

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Essential hygiene messages in post-disaster emergencies World Health Organization This fact sheet outlines some of the key activities in dealing with hygiene promotion in post-disaster emergencies. In carrying out hygiene promotion, you will need to carry out the following activities:

What is hygiene promotion? The goal of hygiene promotion is to help people understand and develop good hygiene practices to prevent disease and promote positive attitudes towards good health practices.

Evaluate current hygiene practices. Plan what you need to promote. Implement your plan. Monitor and evaluate your plan.

Evaluate whether current hygiene practices are good and safe You will need to identify the key hygiene behaviour risks and judge the probable success of any promotional activity. The main risks are likely to be:

Focus of hygiene promotion in emergencies Your aim in carrying out hygiene promotion in emergencies is to:

rower high-risk hygiene behaviour; and sensitize your target population to the appropriate use and maintenance of facilities.

Excreta disposal. Use and maintenance of toilets. Lack of hand washing with soap or alternative. Unhygienic collection and storage of water. Unhygienic preparation and storage of food.

This latter point is important. Your efforts should be directed at encouraging people to take action to protect their health and make best use of the facilities and services provided.

Hygiene promotion is not simply a matter of providing information. It is more a dialogue with communities about hygiene and related health problems, to encourage improved hygiene practices.

Prioritize these by choosing those which pose the greatest health risk. You should look at the resources available to your target population taking into account local behaviours, knowledge and cultural norms. The needs of vulnerable groups should be given particular attention.

Plan which good hygiene practices to promote The understanding you gain from the above evaluation should be used to plan and prioritize assistance. Give priority to targeting those behaviours which pose the greatest health risks. Target a small number of practices for each user group: sustained and repeated messages covering a small number of practices are likely to have greater impact than a large amount of promotional messages centred on several practices. The key is to identify the most harmful practices in each user group and focus on these. Implement a health promotion programme that meets community needs and is understandable by everyone.

Community meeting

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Essential hygiene messages Implement your plan Target specific audiences. It is important that you know who your audience are and that you direct messages at groups responsible for carrying out the activity being referred to. Certain behaviours may be seen to confer status within the community and be adopted for this reason. For example: Fatima built a utensils drying rack for after noticing her neighbour Zainabu, who is a teacher, had one. A woman may adopt the correct disposal of childrens’ faeces upon seeing a health worker doing so.

Messages about diarrhoea in children should be directed at those involved in childcare.

Hygiene messages need to be positive. Hygiene messages should be presented in a positive light making use of humour wherever possible. Nobody likes being lectured to: people will be much more receptive to positive messages. Identify appropriate communication channels. You need to know how your different target audiences prefer to receive information and any cultural aspects to this. Do they listen to the radio, pick up information through informal discussions, use health facilities, rely on religious functions, theatre and dance and so on? It is usually more effective to use the channel that your audience identifies with and regards as trustworthy.

It is desirable that all gender groups (women, men, children and those with disabilities), should receive equal attention. There are reasons why this does not always happen. Women, for example, will shoulder domestic responsibilities in most households. As a consequence, most promotion activities are directed at women, on the premise that if they understand, accept and act upon the messages, the benefits will be immediate. Men, on the other hand, might understand and accept the messages but not act upon them if they are not involved in domestic duties. Identify motives for behavioural change. People may change their behaviour for reasons not necessarily related to potential health benefits, but for totally unrelated reasons. It is important to identify and understand cultural norms and use this knowledge as a basis for articulating motives for change.

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Essential hygiene messages Staff may be recruited from among elders with a lot of life experience, teachers, community leaders, health workers, religious leaders, traditional birth attendants and so on. Although there are no hard and fast rules, a ratio of one facilitator to every five hundred people or one hundred families is recommended.

Mix your communication channels. A message received through a variety of channels is more likely to be remembered. However, there are costs to take into account. Broadcast media is less expensive per capita than is say, face-to-face communication, but information provided one-to-one has greater impact than an impersonal message received through the media. You need, therefore, to balance the costs of using a channel against its effectiveness. Materials. These should be designed in a way that messages will reach illiterate members of your population. Participatory methods and materials that are culturally appropriate offer opportunities for groups to plan and monitor their own hygiene improvements. Facilitators. Facilitators are the people you will use to implement your plan, working with the community, faceto-face. It is important to select the right people as facilitators as they are the single most important factor for the success of a hygiene promotion campaign. Generally speaking, facilitators should be selected from among the target population. They should be able to communicate in the local language and, where possible, be people who are respected within the community. A reasonable standard of education and an enthusiasm for community work are desirable. They should be aware of the constraints that may cause people not to adopt good practices.

Monitor and evaluate the programme to see whether it is meeting targets You will need to review your hygiene promotion programme regularly. Ideally, members of the community should be involved to ensure that issues important to them are covered. The review should evaluate members’ feelings about the hygiene message and whether they need more information. Reviews should also mean you gain feedback about how to improve your programme. It is a good idea to have members decide the frequency of reviews. All information gathered during monitoring and evaluation should be shared with the wider community and interested stakeholders.

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How to measure chlorine residual in water World Health Organization The importance of chlorine in water Many of the most common diseases found in traumatized communities after a disaster or emergency are related to drinking contaminated water. The contamination can be from micro-organisms (Table 1) or natural and man made chemicals (Table 2). This fact sheet concentrates on the problems caused by drinking water contaminated by micro-organisms as these are by far the most common and can be reduced by chlorination. Chemical contamination is difficult to remove and requires specialist knowledge and equipment.

force people to live in poor conditions such as tents or temporary buildings which make it difficult to retain good hygiene practices; and they affect their diet, often lowering their nutritional level and making them more vulnerable to disease.

It is important, therefore, that all people affected by an emergency are provided with water of a high quality. There are a number of ways of improving the quality of drinking water. The most common are sedimentation and filtration followed by disinfection. (These are discussed in other notes in this series). Disinfection (the killing of harmful organisms) can be achieved in a number of ways but the most common is through the addition of chlorine. Chlorine will only work correctly, however, if the water is clear (Box 1).

Table 1. Diseases related to drinking water contaminated with micro-organisms Diarrhoea* Typhoid* Hepatitis* Cholera* *Contaminated water is not the only cause of these diseases; water quantity, poor sanitation and poor hygiene practices also play a role

Box 1. How chlorine kills When chlorine is added, it purifies the water by destroying the cell structure of organisms, thereby killing them. The process only works, however, if the chlorine comes into direct contact with the organisms. If the water contains silt, the bacteria can hide inside it and not be reached by the chlorine. Chlorine takes time to kill all the organisms. In water above about 18oC the chlorine should be in contact with the water for at least 30 minutes. If the water is colder then the contact time must be increased. It is normal, therefore, to add chlorine to water as it enters a storage tank or a long delivery pipeline to give the chemical time to react with the water before it reaches the consumer. The effectiveness of chlorine is also affected by the pH (acidity) of the water. Chlorination is not effective if the pH is above 7.2 or below 6.8.

Table 2. Some chemical contaminants of drinking water that may be a danger to health Arsenic Cadmium Chromium Cyanide Fluoride Lead Mercury

People who live in the same place all their lives and regularly drink contaminated water may develop some resistance to the contaminants and suffer little or no health problems. Communities affected by an emergency, however, are very different. Emergencies have three relevant effects on people, they:

force people to move to new places where the water quality is different from what they usually drink and for which they have no immunity;

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How to measure chlorine residual Chlorine residual Chlorine is a relatively cheap and readily available chemical that, when dissolved in clear water in sufficient quantities, will destroy most disease causing organisms without being a danger to people. The chlorine, however, is used up as organisms are destroyed. If enough chlorine is added, there will be some left in the water after all the organisms have been destroyed, this is called free chlorine. (Figure 1) Free chlorine will remain in the water until it is either lost to the outside world or used up destroying new contamination. Therefore, if we test water and find that there is still some free chlorine left, it proves that most dangerous organisms in the water have been removed and it is safe to drink. We call this measuring the chlorine residual. Measuring the chlorine residual in a water supply is a simple but important method of checking that the water that is being delivered is safe to drink Caution: All forms of chlorine are harmful to health. Avoid skin contact and do not inhale the fumes. Chlorine should always be stored in cool, dark, dry and sealed containers and out of reach of children.

Just after the chlorine has been added to the water to check that the chlorination process is working. At the outlet of the consumer nearest to the chlorination point to check that residual chlorine levels are within acceptable levels (between 0.5 and 0.2 mg/l). At the furthest points in the network where residual chlorine levels are likely to be at there lowest. If chlorine levels are found to be below 0.2 mg/l it might be necessary to add more chlorine at an intermediate point in the network.

When and where to test water The most common place to use chlorine as a disinfectant is in a piped water supply. Regular chlorination of other water supplies is difficult and usually reserved for disinfection after repair and maintenance. The chlorine residual is usually tested at the following points:

The amount of chlorine residual changes during the day and night. Assuming the pipe network is under pressure all the time (see Box 2, overleaf) there will tend to be more residual chlorine in the system during the day than at night. This is because the water stays in the system for longer at night (when demand is lower) and so there is more opportunity for the water to be contaminated which will use up the residual chlorine. Chlorine residual should be checked regularly. If the system is new or has been rehabilitated then check daily until you are sure that the chlorination process is working properly. After that, check at least once a week.

Chlorine added

Water requires 2.0mg/l of chlorine to destroy all organisms

1.5 mg/l

Water not disinfected

Testing for chlorine residual 2.0 mg/l All organisms destroyed but no chlorine left for future contamination

The most common test is the dpd (diethyl paraphenylene diamine) indicator test, using a comparator. This test is the quickest and simplest method for testing chlorine residual. With this test, a tablet reagent is added to a sample of water, colouring it red. The strength of colour is measured against standard colours on a chart to determine the chlorine concentration. The stronger the colour, the higher the concentration of chlorine in the water. Several kits for analysing the chlorine residual in water, such as the one illustrated in Figure 2, are available commercially. The kits are small and portable.

2.5 mg/l

All organisms destroyed and 0.5 mg/l residual chlorine remaining

Figure 1. Effect of chlorine residual

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How to measure chlorine residual

Step 1. Place one tablet in the test chamber (a) and add a few drops of the chlorinated water supply under test.

Step 2. Crush the tablet, then fill chamber (a) with the chlorinated water supply under test.

Step 3. Place more of the same water supply under test (without a tablet) in the second chamber (b). This is the blank control for colour comparison.

Step 4. The level of residual chlorine (R) in mg of chlorine per litre of water (mg/l) is determined by comparing the colour of the water supply under test in chamber (a) with the tablet added with the standard colours on the vessel (chamber (b)).

Note: Chamber (c) would be used if a higher chlorine residual is to be measured.

Figure 2. Steps in determining the chlorine residual in water using a comparator

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How to measure chlorine residual Box 2. Chlorination and intermittent supplies There is no point in chlorinating pipe networks if the water supply is intermittent. All pipe systems leak and when the water supply in switched off, the pressure will drop and contaminated water will enter the pipes through the breaks in the pipe wall. No level of residual chlorine acceptable to consumers will be able to deal with such high levels of contamination. All intermittent water supplies should be assumed to be contaminated and measures taken to disinfect it at the point of use.

A chlorination checklist • • • • • Chlorine needs at least half an hour contact time with water to disinfect it. The best time to apply it is after any other treatment process, and before storage and use. Never apply chlorine before slow sand filtration or any other biological process, as the chlorine will kill off the bacteria which assist treatment, making the treatment ineffective. Never add any solid form of chlorine directly to a water supply, as it will not mix and dissolve. Always make up as a paste first, mixing the chlorine compound with a little water. Disinfection is only one defence against disease. Every effort should be made to protect water sources from contamination, and to prevent subsequent contamination during collection and storage. The correct procedure for applying a disinfectant to water should be strictly adhered to, and water supplies should be monitored regularly to ensure that they are free from bacteria. Otherwise, people may be misled to believe that the water is safe to drink when, in fact, it is hazardous to do so. The optimum chlorine residual in a small, communal water supply is in the range of 0.3 to 0.5mg/l. The chlorine dose required to disinfect a supply will increase if the water is very turbid. In such circumstances, it is best to treat the water to reduce turbidity before chlorination.

• •

World Health Organization WHO Headquarters Avenue Appia 20 1211 Geneva 27 Switzerland Telephone: Facsimile: Telex: Telegraph: (+ 41 22) 791 21 11 (+ 41 22) 791 31 11 415 416 UNISANTE GENEVA

This information has been prepared by WEDC Author and Series Editor: Bob Reed Design: Glenda McMahon Illustrations: Rod Shaw Graphics: Ken Chatterton Water, Engineering and Development Centre, Loughborough University, Leicestershire, UK. Phone: +44 1509 222885 Fax: +44 1509 211079 E-mail: WEDC@lboro.ac.uk Website: www.lboro.ac.uk/wedc

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Delivering safe water by tanker World Health Organization When to use tankers Moving water by tankers should be avoided if possible. It is expensive and difficult to organize. It should be seen as a temporary measure to allow for the development of a more sustainable solution. Tankering, however, is a common method for delivering water immediately after an emergency has happened while more long term measures are being put in place; where the emergency is thought to be temporary and the situation will return to normal soon; and where security and political problems make it difficult to change to a more sustainable approach. In the last case, tankering may continue for long periods – sometimes for years. Tankering is a major logistical operation. It requires a fleet of vehicles that require frequent maintenance and proper management. Tankers full of water are heavy vehicles and the operation may require regular attention to the access routes if they are to remain open. The key to a successful tankering operation is good management, and proper financing. made from flat bed trucks with portable storage tanks attached can be very dangerous if the tank is not securely fastened. The delivery of bottled water may be a short term option but it is expensive and inefficient. It also produces a major solid waste problem from all the discarded empty water bottles.

Tanker management Consider the following points when organizing a tankering programme:

Good management is the key to successful tankering. Identify reliable and capable supervisors. Closely monitor tanker performance, fuel consumption and spare parts use. Get clearance from local authorities and owners before using a water source. Check the water’s quality and reliability before committing to its use. Tankers may have been used for carrying other liquids before the emergency. Always insist on all tankers being properly cleaned and disinfected before being used to carry water (see Note 3). Establish detailed contracts with private tankering contractors. Payment should be based on the quantity and quality of water delivered not the working time. Establish a monitoring system at the delivery point to check the quantities delivered. Make sure the routes to be taken by the tankers are capable of carrying the wheel loads. You may have to reinforce bridges and resurface sections of road. Choose the right tanker for the job. Some sites may be inaccessible and unsuitable for large tankers. Others may require water to be transported over long distances that would be unsuitable for small tractor drawn bowsers. Arrange an adequate supply of fuel. If the area has been hit by an emergency, supplies of fuel may be disrupted and there will be a high demand from other emergency services. It may be necessary to set up a temporary fuel storage depot to ensure a reliable supply.

Types of tanker Water can be carried in a variety of different containers, some specifically designed for the task and others fabricated to meet an urgent need. Figure 1 shows a selection of different vehicles for carrying water. If possible, try to use specially designed water tankers. They will be safer and more reliable. Temporary tankers

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Delivering safe water by tanker The provision of storage tanks increases the efficiency of the tankering system and extends the time over which users can collect water. It also improves the quality of the water as it provides additional storage time before use. There are many different designs for storage tank, some specifically developed for emergency situations and others adapting existing equipment and ideas. Always raise tanks off the ground so that users can get their containers under the outlet tap. Tankering efficiency can be further increased by fitting the tanker with a water pump so that the water can be pumped into the storage tanks rather than allowing it to flow by gravity. Access is improved if the storage tank is connected to a tap stand. This moves the users away from the storage tank that reduces the problems associated with wasted water and vandalism and allows more people to collect water at the same time.

A temporary tanker (Temporaty tankers made from flat bed trucks with portable storage tanks attached can be very dangerous if the tank is not securely fastened.)

A well managed tankering programme is heavily dependent on staff relations. Drivers are particularly important. Make sure they are properly paid, have adequate rest periods and have the proper equipment. Make clear the divisions of responsibility for the different tasks such as loading, chlorination and pump operation. Don’t forget to consider the security of the vehicle and its driver and make appropriate arrangements. If the driver is to look after other machinery (such as water pumps), make sure they are properly trained in their use and day to day maintenance. Tankers are machines and need regular maintenance. Build a regular maintenance schedule into the programme to keep the delivery reliable and ensure a good supply of spare parts and mechanics to fit them.

Water distribution and collection The simplest method of distributing water from tankers is to allow the public to collect it directly from the vehicle. This method is slow and reduces the number of trips the vehicle can do each day. Efficiency can be improved slightly by fitting a tap bar on the back of the tanker but the best method is to transfer the water from the tanker to a storage tank.

Providing water in an emergency is only successful if the users also have suitable containers to collect and store it. Domestic containers come in a wide variety of designs. One of the most popular is the jerry can. Provided it is fitted with a lid, the jerry can is easily carried in the hand or on the head. The problem with jerry cans is that they are difficult to fill, causing a high proportion of water to be wasted, and they are almost impossible to clean on the inside. If used for extended periods they can become a serious health hazard. The other common design of container is the bucket. These are cheap to buy, easy to fill but hard to carry when full. Water is easily spilt during carriage and the large open water surface can easily lead to contamination. These problems can be reduced by fitting the bucket with a tight fitting lid that can be removed for filling and cleaning.

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Delivering safe water by tanker

Emergency water tanks

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Delivering safe water by tanker Calculating tankering requirements A community affected by an earthquake requires 200,000 litres of water a day to be tankered in. The water is to be collected from a borehole 10km from the community. Estimate the number of tankers that will be required to deliver the quantity of water required. The following activities are assessed to take these times: Filling the tanker 20 min Travel time from borehole to community 30 min Offloading time for tanker 10 min Return travel time 30 min Net turnaround time 90 min Add 30% for unforeseen activities 30 min Gross turnaround time 120 min Assume each tanker can work 14 hours per day using two drivers then the number of trips each tanker can make a day is: 14 x 60/120 = 7 If each tanker can carry 5,000 litres per trip then one tanker can transport 5,000 x 7 = 35,000 litres per day Therefore the number of tankers required to deliver sufficient water is 200,000/35,000 = 5.7 say 6 tankers

Further information Davis, J. and Lambert, R. (2002) Engineering in Emergencies – A practical guide for relief workers”, 2nd edition, ITDG Publishing, UK.

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Emergency sanitation – planning World Health Organization Why is it important to plan? The pressure to help people immediately after a disaster often leads to actions being started before they have been properly planned. Wide experience has shown that this leads to a waste of resources, poor service delivery and low long term benefits for the affected community. It is always important to plan sanitation interventions before starting work and there is no reason why this should not apply in emergencies or after disasters.

What is meant by sanitation? The term sanitation means different things to different people. In this note it is taken to mean the collection and disposal of human excreta (urine and faeces). Other wastes from human activities such as solid waste and medical waste are not covered but the principles involved are the same.

Figure 1. Stages in emergency sanitation programme design

Stages in planning Figure 1 shows the main stages in planning emergency sanitation. The main complaint about the planning process is that it takes too long in an emergency. This is not true: Figure 1 also shows the approximate time required for each stage for an affected population of about 10,000.

Rapid assessment and priority setting It is only necessary to intervene in a situation if there is a need to do so. This stage aims to rapidly collect and analyse key information to identify if an intervention is necessary and whether it is of high, medium or low priority.

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Emergency sanitation – planning Table 2. Key data to be collected General description Write a general description of the emergency, affected area and population. Include socio-political, institutional, demographic, health and geographical information. General information Organisation carrying out the assessment Name of assessor(s) Position of assessor(s) Dates of assessment Maximum level of intervention (short-term or long-term) General location or site affected Logistics and resources available Human resources available Nature and history of emergency Government involvement Conflicts and likely resolutions Origin of affected population Seasonal/climatic implications Existing/potential donors Other organisations working in the area including current and planned activities Demographic data Approximate number of affected people Breakdown of the population by sex Breakdown of the population by age Proportion of vulnerable groups (e.g. female-headed households, children, sick, disabled, etc.) Average family size Likely increase in population over next month Geographical information A sketch map should be produced and the following features identified and located: Location and types of existing sanitary facilities with estimates of key distances from dwelling areas Location of indiscriminate dumping of solid or medical waste Areas of indiscriminate excreta disposal Location of key public services/institutions Water sources Water storage and distribution points Pooling of wastewater Burial / cremation sites Groundwater levels Ground conditions Geological features Slope directions and drainage General description Write a full description of the current facilities and practices (including anal cleansing). Include how facilities were constructed, operated and maintained with general comments on quantities, qualities and cultural factors. Quality Are existing facilities technically appropriate? Are existing facilities socio-culturally acceptable to all users? What are the potential hazards for disease transmission? Is there any potential contamination of food and water sources?

...continued

Are any excreta disposal facilities breeding sites for vectors or pests? Are appropriate anal cleansing and handwashing materials available? Is there evidence of any indiscriminate defecation or potential for direct human contact with excreta? For how long are current facilities and practices sustainable?

Quantity What is the ratio of domestic facilities (cubicle or space) to population? If required, what is the ratio of population to facilities for children, disabled or elderly? If there is a need for facilities in public places or institutions, what is the ratio of facilities to unit of measure? What is the maximum one-way walking distance for users? Usage What proportion of the affected population has access to appropriate facilities? What groups do not have access and why? What proportion of the affected population is using the appropriate facilities correctly on a regular basis? Are facilities maintained hygienically?

Box 1. Data collection principles The main things to remember when collecting information are: • • Collect it from as many sources as possible to reduce bias and inaccuracies Be aware of local political and social structures so as not to raise unrealistic expectations Consider the effects of the data you collect on your decisions Keep good records of what you have learned and from whom Remember that situations change rapidly in an emergency and things may not be the same tomorrow as they are today Get a good interpreter if you are working with people who speak a different language from you

• • •

•

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Emergency sanitation – planning Table 3. Recommended minimum objectives for safe excreta disposal Criteria Quality Immediate • • Technically basic Barely socially and culturally acceptable Basic health protection measures in place Technology sustainable for one month Short-term • • Technically appropriate Socially and culturally acceptable Minimal health hazard Technology sustainable for six months Long-term • • Technically very appropriate Very socially and culturally acceptable No health hazard Technology sustainable for three years

•

• •

•

Quantity

•

Ratio of one space/cubicle to 100 persons accessible to all population or immediate responses only Maximum walking distance 70m (one way) Availability of sufficient numbers of facilities at:

•

Ratio of one space/cubicle to 50 persons accessible to all population Maximum walking distance 50m (one way) Availability of sufficient numbers of facilities at:

•

Ratio of one space/cubicle to 20 persons accessible to all population Maximum walking distance 25m (one way) Availability of facilities at:

• •

•

1. Medical centres (one latrine space to 50 beds or 100 outpatients) 2. Schools (one to 50 girls and one to 100 boys) 3. Market areas (one to 100 adults and one to 50 children) 4. Feeding centres (one to 100 adults and one to 50 children)

1. Medical centres (one latrine space to 20 beds or 50 outpatients) 2. Schools (one to 30 girls and one to 60 boys) 3. Market areas (one to 50 stalls) 4. Feeding centres (one to 50 adults and one to 20 children)

1. Medical centres (one latrine space to 10 beds or 20 outpatients) 2. Schools (one to 15 girls and one to 30 boys) 3. Feeding centres (one to 20 adults and one to 10 children) 4. Market areas (one to 20 stalls) 5. Offices (one to 20 staff)

Usage

•

50% of affected population has access to domestic facilities (100% in medical and feeding centres) 50% using facilities correctly on a regular basis

•

75% of affected population has access to domestic facilities (100% in medical and feeding centres 75% using facilities correctly on a regular basis

•

95% of affected population has access to domestic facilities (100% in medical and feeding centres) 95% using facilities correctly on a regular basis

•

Should you get involved? External organisations should only get involved if the affected institutions and population are unable to deal with the situation and if the health of the population is getting (or is likely to get) worse. Table 1 suggests health data that will assist in deciding whether to intervene.

quickly but in sufficient detail that the information collected is of use for analysis (Box 1). Table 2 suggests the key information you should collect.

Minimum objectives In emergencies the normal routes for making decisions on what technologies to use do not work. Instead, a set of internationally recognised standards are used to ensure that the services provided to people in distress are broadly the same all round the world. Table 3 sets

Data collection Data must be collected to assess the problems and needs of the affected population. This must be done

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Emergency sanitation – planning out accepted standards for emergency excreta disposal. These standards are used decide what should be provided and whether they are a success. communities in the planning and design process is beneficial to their recovery as it gives them self respect and promotes continued independence. The affected community should be involved as soon as a decision has been made to intervene, this usually means at the detailed design stage.

What to do? A comparison of existing facilities with those suggested to meet minimum objectives will tell you if any further work needs to be done and if it is urgent.

Outline design Assuming the assessment has shown a need to intervene, this stage develops an outline plan for what should be done and how. The plan contains sufficient information for senior officials to decide whether action should be taken and to allocate resources. The outline design should include brief information on the current situation and problems, an analysis of the causes of the problem, an outline of possible solutions and general estimates labour, materials and costs.

Box 2. Stages in an emergency Emergencies last from a few days to many years. The type of intervention required will not be the same for all. In general emergencies can be divided as follows: Immediate After the impact of the disaster. Typified by great instability and high mortality. Typically lasts one to two months. Short term The period of stabilisation where the aim is to reduce morbidity and mortality. Typically up to six months Long term Recovery and resettlement of the affected community. Lasts several years.

Immediate action Sometimes the threat to health is so high that something must be done immediately to prevent widespread disease and death. Immediate actions are targeted at providing a quick response to an urgent situation while a more sustainable solution can be developed and implemented.

Detailed design Once approval for a proper response to the problem has been granted, a detailed plan and design must be drawn up prior to beginning implementation. The design process is the same as for any other sanitation project except that it must remain flexible in case the situation changes rapidly.

Further information Harvey, P., Baghri, S. and Reed (2002) Emergency Sanitation – Assessment and programme design, WEDC, Loughborough University, UK.

Community participation Affected people have views and opinions, just like any others. There is no reason to treat them any differently than other communities except to make allowances for the trauma they have experienced. Involving

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Emergency sanitation – technical options World Health Organization The immediate provision of clean water supplies and sanitation facilities in refugee camps is essential to the health, well-being and, in some cases, even the survival of the refugees. Sanitation is usually allocated a much lower priority than clean water, but it is just as important in the control of many of the most common diseases found in refugee camps. Sanitation is the efficient disposal of excreta, urine, refuse, and sullage. As indiscriminate defecation is normally the initial health hazard in refugee camps, this note outlines ways in which it can be controlled temporarily while long-term solutions are devised.

Figure 1. Plan of a defecation field

Immediate measures The technical options for emergency excreta disposal are limited and simple. If they are to work, however, they must be managed well and be understood and supported by the community. The immediate tasks at a new camp include:

Preventing defecation in certain areas When a large group of people are excreting indiscriminately, it is necessary, first of all, to protect the food-chain and water supplies from contamination. This means preventing people defecating on:

obtaining the services of a good translator and consulting with all interested parties including representatives of the refugees, aid agencies, and government officials;

the banks of rivers, streams, or ponds which may be used as a water source. If water is to be abstracted from shallow wells, then it is important to ensure that these wells are situated upstream of the defecation areas; or agricultural land planted with crops, particularly if the crops are soon to be handled or harvested for human consumption.

surveying the site to gather information on existing sanitation facilities (if any), the site layout, population clusters, topography, ground conditions, and available construction materials; preventing defecation in areas likely to contaminate the food chain or water supplies; and selecting areas where defecation may safely be allowed.

Keeping people away from such areas may not be easy, particularly where traditional habits make such practices common. It may be necessary to construct a physical barrier, such as a fence, which may need patrolling. Immediate measures to control indiscriminate defecation should not be solely negative, though; it is much better to designate areas where defecation is allowed than to fence off those that are not.

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Emergency sanitation – technical options Defecation fields Areas with fixed boundaries within which defecation is permitted are known as 'excretion' or 'defecation' fields. The use of these fields localizes pollution, and makes the management and the cleaning of the site easier. They should be located carefully so that they are easily reached by the community but do not pollute water supplies or sources of food. It is better if there are a number of fields at roughly equal intervals over the site area, as this will reduce the walking distance for most users and allow for flexibility of operation and the separation of the sexes. The defecation field should be as large as possible, but it should not be open for use all at once. It is better to divide the field into strips so that a different strip can be used each day. The area of the field farthest from the community should be used first, so that people do not have to walk across contaminated ground to reach the designated area (Figure 1).

Figure 2. A shallow family latrine

Intermediate measures The life-span of the excretion fields is not long because the areas polluted by excreta cannot be used again unless a system is established to cover the excreta with soil. Their purpose is to allow time for latrines to be built. The ideal solution is to provide each family with their own latrine, but unless this is the simplest of structures (Figure 2), it is neither feasible nor advisable immediately. In the early days it will not be known how long it will be before the situation which has caused the disruption to the refugee community will return to normal. Furthermore, refugees will naturally be unsettled at this stage, and may be unable or unwilling to commit themselves to the maintenance of permanent or semi-permanent

Figure 3. Trench defecation fields

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Emergency sanitation – technical options structures that may suggest that their displacement will last a long time. An intermediate solution is required. It is usual for this to be some form of communal latrine, as communal latrines are quick and cheap to construct. Some are commercially available, but these are expensive and take time to transport to the site. In most cases, 'trench' latrines provide the simplest solution (Figures 3 and 4).

Trench latrines A trench latrine is a rectangular hole in the ground. The hole should be dug as deep as possible — about 2m and may be lined with timber where there is danger of collapse. It may be of any convenient length, usually between 5 and 10m, and between 1 and 1.5m wide. The trench is spanned by pairs of wooden boards on which the users squat (see Figure 4). There is a gap between the boards through which the users excrete. An alternative (and better) solution is to use plastic squatting slabs overlaying the boards if these are available. Preferably, each pair of boards is separated by a simple screen to provide privacy. In wet weather a roof is needed to prevent the trench from filling up with rainwater. A drainage ditch should be built to divert surface water. Each week the contents of the trench are covered by a 100 to 150mm-deep layer of soil. This will reduce the smell and prevent flies from breeding in the trench. When the bottom of the trench has risen to within 300mm of the surface, the trench is filled in and the latrine is closed. A trench latrine system is very labour-intensive and requires constant supervision. Not only must the contents of each latrine be covered each day, but new latrines must be prepared, old ones filled in, and regularly used latrines cleaned. Close supervision is essential. A poorly maintained latrine will quickly become offensive to the community and will not be used.

Figure 4. Deep trench latrines

Mobile package latrines In the North, mobile package latrines are common. There is no reason why they cannot be used in other places provided provision is made for the ultimate disposal of the excreta.

Borehole latrines In areas with deep soil, many borehole latrines can be built in a short time using hand augers. The holes are usually 30 to 50cm in diameter and 2 to 5m deep. The top of each hole is lined with a pipe, and two pieces of wood comprise the footrests. Borehole latrines should be closed when the contents are only 500mm from the surface.

Long-term solutions Trench or borehole latrines are only an intermediate solution because their operation is so labour-intensive and requires constant supervision. As soon as it becomes obvious that the community is likely to remain disrupted for any length of time, longer-term solutions should be sought. In most cases, some form of on-site sanitation will be most appropriate.

Making use of existing facilities If refugees settle in or near urban areas, it may be possible to make use of existing facilities such as sewers, public toilets, bucket latrines, or drains.

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Emergency sanitation – technical options Community mobilization The safe disposal of excreta in refugee camps is primarily the result of good supervision and management, and this can only be achieved with the full co-operation of the community. It is essential, therefore, that the community is fully consulted at all times and that their views are considered and their suggestions implemented. Problems may arise as immediate sanitation measures usually conflict with personal habits and social customs, but strict control measures at the outset, when people are still disorientated, will usually help them to become accustomed to new ideas and methods. Later, the supervision of the excretion fields and the policing of protected areas can easily be done by the community itself. The co-operation of the community will only be gained and retained if it is kept fully informed of what is being done and why. Information is communicated best through group meetings and personal contact. contact is more appropriate. Improving hygiene awareness, particularly among mothers, is usually better achieved on a one-to-one basis or within very small groups. Such education is long term and slow, but it should be started as soon as possible since it is often easier to establish new behaviour patterns in a community before it becomes established.

Labour The day-to-day operation of latrines and programmes of education require substantial labour. While key management posts are likely to be provided from outside the area, much of the initial routine work can be done by the community. In most cases the community is only too willing to help since it gives people something to do, prestige, and possibly a source of income. Latrine supervision is not a popular job and will almost certainly have to be paid for. Motivation may be improved by providing a uniform and protective clothing or installing special bathing facilities for supervisors. People working on latrine operation require little or no training; those involved in health education and information dissemination will require more.

Group meetings Group meetings can be used to advise the community about what is proposed, how the systems will operate, and why they are important. Such meetings should give the community an opportunity to question and advise on what is being proposed. It is important that every effort is made to include as many of their views as possible. In the early stages, the community is usually too tired and confused to contribute to the proposals, but this stage quickly passes and soon the community will start to take a lively interest in its surroundings.

Further information Harvey, P., Baghri, S. and Reed, R.A. (2002) Emergency Sanitation – Assessment and programme design, WEDC, Loughborough University, UK.

Individual contact Group meetings are effective at passing on general information, but there is a possibility that some sections of the community will not be reached and these meetings are not appropriate for dealing with individual problems. For these situations, personal

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WHO EHA Publications Publication No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Publication Title Draft Emergency Preparedness & Disaster Response Plan for the Heatlh Sector in Nepal Emergency Preparedness & Disaster Management for Hospitals Emergency Preparedness & Disaster Management for Hospitals (Nepali) Establishing A Mass Casualty Management System Structural Vulnerability Assessment of Hospitals in Kathmandu Valley Health Sector Emergency Preparedness & Disaster Response Plan Nepal Computer-based Mass Casualty Management Simulation Exercises: MUSTER Guidelines Non-Structural Vulnerability Assessment of Hospitals in Nepal Best Public Health Practices in Emergencies for Disaster Health Workers Non-structural Safety in Health Facilities Seismic Vulnerability Assessment of Hospitals Establishing A Mass Casualty Management System (Nepali) National Seminar on Biological, Chemical, Radiological Emergency Preparedness & Response (Radioactive) Best Public Health Practices in Emergencies for Disaster Health Workers (Nepali) Public Health District Profiles: Baseline Data through Secondary Sources Mass Casualty Management Trainer's Manuals Non-structural Safety in Health Facilities (Nepali) Health Interventions in Crisis-affected Communities of Nepal Health Action in Crisis in Nepal: WHO CAP Programme Outline Environmental Health in Emergencies: Technical Notes on Water and Sanitation Published in May 2001 Feb 2002 Feb 2002 Jun 2002 Aug 2002 Sep 2003 Dec 2003 Dec 2003 Mar 2004 Mar 2004 Apr 2004 Jun 2004 Jun 2004 Sep 2005 Dec 2005 Jan 2006 Mar 2006 Oct 2006 Dec 2006 Mar 2007

World Health Organization UN House, P. O. Box 108 Pulchowk, Kathmandu, Nepal

Key facts

Organisation World Health Organization (WHO)

Document type Publications

Adoption date December 31, 2007

Source World Health Organization