Project | Conference | Proceedings | UW-DMC
This paper encompasses the topics of water, sanitation, hygiene and vector management and presents a cohesive set of principles unifying all of these in a general environmental health approach. The principles deal primarily with issues of site selection, protection of water sources, standards, participation of the community, and the use of experts. The best practices section focuses on the general approach to environmental health management. Some generally applicable standards are presented as well as a developed list of resources in this area.
This paper was prepared by James Good of InterWorks. In addition to the resources listed in the paper, the following people provided significant contributions:
Eduardo Perez - is Technical Director for Engineering and Technology of the Environmental Health Project of the US Agency for International Development in Washington, DC.
Claude Rakotomalala - is a senior sanitary engineer for the Professional and Technical Support Services of the United Nations High Commissioner for Refugees.
Gary Shook, MPH, Sc.D. - has been a health specialist for the Asian Disaster Preparedness Center at the Asian Institute of Technology in Bangkok, Thailand, and is currently at Boise State University in Idaho.
Richard Swenson - is a co-founder of Public Health International in Roseburg, Oregon, US.
This paper is a synthesis of the efforts of all of those cited above and as such does not express the viewpoint of any single resource, contributor or organization.
1. Environmental health planning must be held as the highest priority in the design of and programming for emergency settlements. No amount of curative health measures can offset the detrimental effects of poor environmental health planning for communities in emergency settlements. Well-integrated environmental health programs, which include the provision of sanitation, water, and drainage systems, play a major role in protecting the health of those in emergency settlements.
2. Environmental health begins with site selection. Site selection must be an integral part of the overall planning process. When multiple sites are available - even when none of these are deemed desirable-the criteria for selecting the best one must include the potential for good environmental health systems. Site planning must be integral with the environmental health plan, including the collection, disposal and treatment of excreta and other liquid and solid wastes. The physical characteristics of the site (vegetation, topography, nature of the soil and subsoil, and other attributes) together with the socio-cultural profile of the beneficiary community are determinant factors which must be taken into account. To expect that sanitation issues can be addressed at a later stage (once emergency settlement has become "permanent" and other basic systems are in place) is a false hope, which has often led to complex problems and the expansion, rather than the control, of emergency situations.
Access to adequate sources of potable water is a key component of site selection for emergency settlements. The most desirable water source is ground water, which is often more desirable than surface water, which in turn is more desirable than rain water. Trucking water from remote locations should be considered only as a temporary measure only unless it is demonstrated that it is the most practical and least expensive method to provide adequate quality and quantity of water to the settlement.
3. Access to a minimally-acceptable amount of safe drinking water is a basic human right. Accepted, quantifiable standards should be applied in the provision of water to emergency settlements. However, a universal pre-determination of such quantities is not appropriate for all situations. Factors such as climate, prevalent diseases, and types of facilities needing water will all affect the basic planning criteria. Proposed values for different climatic situations are listed in the Standards section of this paper.
4. In cases of extreme emergency where minimum standards cannot be adequately met, a large quantity of reasonably safe water is preferable to a smaller amount of relatively pure water. Especially in emergency conditions, water quantity will be more important than water quality. In the most extreme case polluted water is preferable to no water at all. In less severe situations it is advisable to focus quickly on provision of an adequate quantity of water well in advance of upgrading water quality, especially in cases where it is possible to manage good sanitation programs as adequate excreta sanitation is the best way to control water borne diseases.
5. Water sources must be protected from pollution. The impact on the local or regional water source (watershed areas of rivers, lakes and aquifers) must be considered in the planning for an emergency settlement. Runoff from the emergency settlement site including waste water and sewage must not pollute water supplies. Once a water source has been selected, direct access to it should be strictly prohibited except for authorized persons only. A means of protection against access (and therefore contamination) must immediately be installed. Some options are; fencing, cut-off trenches or other drainage works to protect water sources from site run-off, vegetation planting, guards, and public information along with enforcement.
When using ground water, the question of how to raise the water is the main issue. There are numerous alternatives for this operation depending upon resources. It is better to expend resources to obtain water in the most reliable and sanitary manner than to pay to clean it up after it is contaminated in the raising process.
6. Environmental health planning should be designed with input from the emergency settlement community. In emergencies the general rule regarding environmental health systems is "act now - improve later". This is a strategy put into place under emergency conditions in order to avoid, for example, the rapid pollution of an entire site with human excreta. Nevertheless, issues related to cultural norms, traditions and religion (s) of the resident community are still essential. Environmental health strategies, to be effective, should be tied to cultural norms and traditions. As such, the environmental health program should be designed with input from and understanding by the emergency settlement community. Failure to do so may lead to a disruption, or failure, of the environmental health program and an increase in the very health hazards that were targeted by the initial response.
It is recognized that emergency settlements are atypical communities which may require services different from the experience of the residents. The emergency nature of such settlements may also limit wider input. For example, nomads without knowledge of pit latrines may, nonetheless, be served best by their use of them in high-density camps. Urbanites from developed countries will have to use non-flush facilities until damaged municipal systems are restored to service. It is imperative that public information and education campaigns accompany the introduction of systems which are unfamiliar to the community. In such cases there must be a distinction made between those aspects of the water supply and excreta disposal systems which are simply different from those previously used by the community and those which are inappropriate as emergency responses.
7. Environmental health programs must insure an adequate number and location of sanitation facilities, solid waste disposal points, and water distribution points. Sanitation, waste disposal, and water distribution systems within the emergency settlement community must be equitable for all residents. This is achieved through installation of an appropriate number of suitably located; excreta disposal facilities, such as toilets, latrines or defecation fields; waste pick-up points, and water distribution points. Coordinated scheduling of water distribution, where required, and dissemination of public information to the community regarding the environmental health service facilities of the settlement may also be necessary.
8. Both local and technical expert advice must be sought for planning and implementing water and sanitation systems. Many of the issues surrounding the suitability of water supply and sanitation are technical in nature and require expert technical advice. Expert local knowledge of the area, the people and their traditional customs is also essential. While expatriate technical advice may be required for development of new, rural sites, it may be generally presumed in urban situations that those involved in the day-to-day operation of the local urban water and sanitation systems can provide the best expertise, as they have intimate knowledge of the workings of these systems. It is essential that consultants, advisors, or others leading the environmental health programs have people, management and administrative skills as well as technical skills.
9. Good water, sanitation, and hygiene education practices in emergencies should be no different from those in "regular" development programs. The basics of community education and information campaigns are the same regardless of the "emergency" element of the community's situation. Those practices of personal hygiene which are promulgated in developmental campaigns aimed at reducing morbidity are exactly the same as those recommended for emergency settlements. The only difference is that the results of failure to change behaviors in the community will be far worse for a an emergency settlement community than for a "normal" developing community. Hygiene education and information programs, where required, are at the center of environmental health management. The aim of all such programs must focus on changing behavior of the community members in their homes as well as in the community.
Environmental health provides the best approach to the technical issues of water provision and excreta disposal. Control of the environmental pathways in which pathogens and other agents may harm the inhabitants of emergency settlements must be maintained through an integrated and effective environmental health management system. All services that protect the settlement inhabitants from environmentally-borne disease are interrelated and must be managed in an integrated way, giving priority to those services most needed but without exclusion of the others. Provision of potable water; adequate shelter; suitable sewage and waste disposal; protection from vectors, pests, and damaging air pollutants; delivery of clean food stocks and protection from noise and physical hazards must all be coordinated in an integrated manner which optimizes health.
For more than two decades, it was thought that the best approach to "environmental health" (usually not using this terminology, however) was to combine environmental sanitation and water programs. In fact, especially where resources were lacking, priority was given in most cases to water at the expense of environmental sanitation. Also, the users' willingness to participate in sanitation programs was traditionally very low. Making this even more difficult was the fact that there was very little political will for the funding of such activities, since sanitation activities were never very highly regarded.
It is therefore recommended that environmental health planning be an integrated system of activities. The management of sanitation, and especially excreta management systems, must be treated as a priority topic in its own right and not simply as an add-on component of a water supply program. Sanitation-although integrated with the whole program-must have its own dedicated resources and time-frame if the best results in the overall environmental health system are to be achieved.
The following points are the key recommendations for achieving implementation of the principles of environmental health.
1. Getting it done
The first activity is to take a skills and knowledge inventory of the affected population. Teachers, public health officials, and business leaders often provide excellent resources to be used in the promotion of an environmental health program. Identify local leaders who will be able to introduce the program to the community or to gain acceptance of the program by the community. Explain to people that the point of such programs is primarily for the protection of the community, especially for those most vulnerable to environmentally-borne disease and infection, i.e. the elderly and the young. When it is understood that programs are for the benefit of the children, then community support should be forthcoming. Organize the community into blocks or groups to be responsible for their own areas.
2. Education programs
Before designing any emergency environmental health education program, one must first determine what is important to that particular community. Only after this step can one engage the community in a meaningful environmental health education program. It doesn't work to teach people things they don't care about. Leadership will develop and the local community will teach themselves only if they are motivated by interest or because the subject satisfies a felt need.
The outside expert can act as a trainer of trainers and a catalyst for environmental health education programs. Education is central to many aspects of managing the day-to-day functioning of an emergency settlement, and this education must be carried out simultaneously in many ways. For example, if people want to learn English, teach them English, but use environmental health topics for reading material as well.
"General hygiene, as a component of environmental sanitation involves specific considerations. As a mater of fact, habitat hygiene, food hygiene and personal hygiene, while being integral parts of environmental sanitation, are more a matter of health education and community sensitization than of sanitary engineering as such.
It is nevertheless worth underlining that education in general and health education in particular are to be sustained by visible and concrete activities in the field - what sanitary engineering precisely aims at. As for community participation, it will remain only an interesting concept as long as the community is not provided with the necessary resources - human, institutional and material - for members to be able to assume their responsibilities in this domain" (Rakotomalala, 1994, p. 41).
3. Vector Control
The control of disease vectors such as mosquitoes, flies, and rats and fleas is an important part of an environmental health approach to protecting community members from disease. There has been a tendency to use poisons for the control of all of these vectors. Especially in emergency situations, the rationale exists for using those programs or approaches with the fastest short-term results. The problems with these approaches are twofold. First, they are dangerous to the human population as well as to the vectors they target, and mistakes and accidents often occur in the application of the poisons. Secondly, even when short-term successes in the control of vectors are achieved, it is common that longer-term environmental control approaches are not put into place. The result over time, therefore, is to endlessly resort to short-term measures.
Plainly, in an environmental health approach to vector control, the environment must be manipulated for vector proliferation to be controlled on a lasting basis. Managing the environment in this way, however, takes more work and is not as quickly rewarding as insecticide spraying operations. Community involvement is also a prerequisite for the success of such activities and community members must be sensitized to the value of such programs.
4. Site drainage
Drainage from newly developed sites for emergency settlement is a critical aspect of environmental health which must be considered at the time the initial site development decisions are being taken. If left unattended, the lack of forethought about natural drainage patterns will result in impassable roads during rainy periods; stagnating ponds and pools which present many problems including mosquito breeding habitat, unsanitary latrines and other facilitates; and the general advancement of disease throughout the community. Drainage must be assured around all water using or water producing facilities such as washing/laundering areas, water supply points, latrines, schools, clinics, markets. and individual family shelters. Families can and will generally provide their own small scale drainage network around their own houses for the control of limited amounts of water, however the provision of network drainage systems into which these small drains can lead must be planned out ahead of time as it can be very difficult, if not impossible, to move individual, family, and community structures once they are set in place. Especially in situations where there is a marked wet season/dry season cycle, emergency settlement populations may not be able to predict the seasonal increase in drainage problems when they begin to settle in a previously unoccupied site (these sites are often unoccupied precisely because they are difficult to use, are prone to seasonal flooding, or are inconvenient for development for some other reason).
The water drained away from heavily used facilities may be removed to surface water sources such as rivers, lakes, or the sea. In cases where, due to topography, it is not possible to drain wastewater to safe areas away from the community, it may be necessary to use soak pits or soakaways. These are simply drainage areas with gravel beds or other porous material which are designed to facilitate the soaking of water into the ground. The planting of water-thirsty trees such as bananas or papayas at the edges of these soakaways (in those regions in which they thrive) has also been found to be extremely beneficial.
In areas of high rainfall and relatively flat sites, the improper construction of roads often aggravates poor drainage systems. Due to the muddy conditions during rainy periods the roads are typically elevated on a compacted base to raise them out of the mud and to allow year-round vehicular access. When this is done without adequate consideration for site drainage, the roads act as dams holding water within the network of elevated roads. This causes water to stay longer and increases problems for the developed areas of the site. Overall site drainage must be considered before the improvement of access roads so that culverts or other drainage devices can be installed as the road improvements are developed. To correct problems afterwards is much more expensive and disruptive to the overall functioning of the community.
5. Setting and Meeting Water Supply Standards
The priority goal of water provision systems is to get a large supply of reasonably clean water to the emergency settlement community for drinking (potable water), cooking, washing, laundering and other uses. The determination of "reasonably clean" and "large amounts" are to be found in the Standards section of this paper and in the following general discussion. The supply of potable water must be considered as a component of total water supply to emergency settlements. However, where a distinction is made, the listing under the Standards section of this paper is proposed as a useful guideline for quality and quantity standards for various situations.
Surface water should always be assumed to be contaminated. Except when settlements are located upstream from sources of contamination, treatment strategies are a major consideration. In some cases infiltration galleries, using natural sand and soil as filters, provide adequate protection from mass pathogenic concentrations. Chemical contamination may require activated charcoal, coagulation, precipitation/filtration or other chemical treatment systems. In any case, sedimentation should be the minimum treatment for surface water, followed by chlorination or other disinfection. Depending on the raw water characteristics, it might also be advisable to install coagulation/flocculation basins above the settling tanks. In this instance plans must also be made for the disposal of the sludge resulting from these basins.
"The objective of any treatment system is to bring the water to an acceptable level of clarity so that the chemical used to disinfect it can be as effective as possible. The overall aim of the process is to kill pathogens in the water and thus minimize the risk of transmitting disease through the water supply. Particulate matter can encourage the growth of bacteria and protect pathogens against the effects of disinfection. The simple chlorination of cloudy (turbid) water, for example, will require more chlorine than clear water and even then the water may still not be safe to drink. Water treatment, therefore, aims first to remove pathogens and particulate matter by mechanical and biological means (settlement, filtration, etc.) before relatively clear water can be finally treated by disinfection" (Chalinder, 1994, p. 40).
Even when the water source is good quality, chlorination is recommended, especially in cases where water is collected at communal tapstands and carried and or stored in containers. The point of such chlorination is to achieve a level of active chlorine available in the water at the collection point so that it can disinfect the (often) contaminated containers. The provision of clean water is useless if in the final instance it is contaminated by poor hygiene practices such as dirty water containers. This illustration also points out the need to maintain public awareness and education programs relating to environmental health issues.
7. Protection of Water Sources
Prevent human and animal access to surface water sources. Sources should be fenced and protected by means of drainage ditches against contamination by site run-off water. The specific nature of the protection required for the water source will depend on the configuration of the water shed as well as other factors. In addition to fencing and ditching, vegetative plantings, catch dams and terraces may also be employed. Any communal activities such as swimming, laundering, bathing, etc. should take place downstream if using river sources, or at designated areas if using other large surface water sources such as lakes.
Hand dug wells should be properly covered, provided with drainage facilities, and fenced. Where water is collected by means of a bucket and rope, users should not be authorized to dip their own buckets into the well, but rather, should use a communal bucket instead.
8. Delivery and Distribution Systems - "Hardware"
Hand pumps may be preferred in smaller settlements (<5,000 people) with modest densities. Pumping water to overhead storage tanks with at least a 6-12 hour reserve capacity is usually best done in concert with piped distribution to designated tapstands or distribution points.
When long-distance hauling of water is required due to lack of other more economical and sustainable options, lorries with bladders or water tankers can be used to transport water. In order to use maximum truck capacity, metallic tanks with baffles are typically a better option. When transporting water, additional issues such as the following must be considered:
For emergency settlements requiring development of new water systems, centralized water supply systems should be installed comprised of a pumping station, storage facilities, chlorination system, and a gravity distribution system through a series of standposts (one for approximately each 250 users.)
A basic part of the water delivery system is the container in which water is collected from the public access point (a tapstand or other water point). As such this element of the system must also be adequately planned for and not left to chance. Appropriate containers (preferably jerry cans or other durable, easily cleaned containers with tight fitting lids) are to be provided to each household for the collection and storage of water. A combination of 10 and 20 liter jerry cans may be considered adequate for these purposes.
Storage requirements for individuals in emergency settlements may be considered to be on average 20 liters/household/day. The target for individuals should be 10 liters/person/day as the ultimate goal. Low storage in houses is important to minimize long-term storage where water can become contaminated or result in mosquito breeding.
9. Delivery and Distribution Systems - "Software"
Once total requirement standards are met, equitable distribution is almost always problematic: corruption, control of resources by those with social status, or military power, and simple mismanagement due to lack of training and public education all contribute to poor distribution. The "software" component of the system should include (among other things), a water committee whose members are designated by the larger emergency settlement community. Such committees should have the full power to recruit, post or dismiss water attendants, to set up tariff and collection systems as appropriate, to decide upon the use of available resources, etc. Through this committee, responsibility for managing the system can be gradually transferred to the community. Sufficient outside technical assistance to insure proper maintenance and support may be required if it is beyond the means of the emergency settlement community.
10. Monitoring Water Distribution and Quality
The minimum quality monitoring parameter for a water supply system for an emergency settlement should address pathogenic or indicator bacteria. In urbanized areas, a strong investigation for heavy metal and organic chemical should be conducted. The particular technical methods for analysis of water quality are not addressed in this paper, as they should be determined with appropriate field expertise given the context and resources at hand. However, ground water quality should be monitored regularly at least weekly, and primarily for bacteriological tests for E. Coli.
"Biological and physical indicators can easily be monitored using simple analysis methods and kits. Portable kits specifically designed for this purpose are available. Reliable and relatively inexpensive water test kits such as the Delaqua, which was developed jointly by the Roebens Institute at the University of Surrey, UK, and OXFAM specifically for use in emergencies will cost from $1,500, and are widely used.
"A more contentious aspect is that of who has responsibility for water quality monitoring. Regular monitoring is very important. Frequently it is the agency providing the water which, for its own reasons, takes on the responsibility for reporting on its quality; this can be acceptable to other agencies when there are no problems, but if outbreaks of water-related diseases occur it will cause considerable friction. It is preferable that a third party should have responsibility for monitoring, recording and reporting on biological quality concerns. Local water departments may have this capacity; failing that, another agency with no direct interest in health service provision for the emergency should be used" (Chalinder, 1994, pp. 34-35, emphasis added).
Aside from monitoring for quality, it is often necessary to monitor the quantity of water actually being used in the household. It may be difficult to accurately measure this for the amount taken from the water source as waste through spillage and leakage may be considerable. One way to assess the amount of water actually used by an emergency settlement community regardless of the system type (centralized distribution through standposts, motorized- or hand-pumps, or other systems) is to check the storage capacity at the household level and then to establish how many times each day these containers are filled.
11. System Management
Policies affecting the overall maintenance and use of the water distribution system which have been set by the system users have proven effective. Community-run systems have helped to eliminate abusive control of water systems by gangs in some camps for Vietnamese Boat People.
Operation and Maintenance (O&M) of these systems should be organized through the community structure as soon as possible, through O&M teams or committees.
Contingency arrangements should always be made for unavoidable breakdowns and repair periods. Stand-by pumping equipment should always be provided as an integral part of any system. In cases where wells are equipped with hand pumps, spare parts should be stockpiled together with the necessary tools for their replacement. Additionally, identification, recruitment and training of the water attendants, mechanics, and others on the O&M committee are an integral part of any emergency settlement water provision strategy.
12. Urban Systems
Especially during and after conflict situations with active shelling and as well as with earthquakes, urban infrastructure systems for the delivery of water and the disposal away of sewage may be damaged beyond use. In such situations entire populations of such towns or cities may be considered as emergency settlements. In these cases the urban dependents on piped systems are likely to be even more vulnerable than their rural counterparts to water borne diseases and other effects of the lack of clean water. The most vulnerable people are the elderly and infants, and children who may already be weakened due to other effects of the conflict or emergency situation.
Water systems have long been military targets due to the very debilitating and demoralizing effect that the destruction of such systems have on communities. "During the Gulf War (1990-1991), air strikes rendered Iraqi hydroelectric plants and water pumping stations totally inoperative. In Afghanistan, the traditional irrigation infrastructure was demolished at the outset of the conflict. Fourteen locations in Bosnia-Herzegovina had had their water supply cut off in July 1994. Three of the cases were caused by deliberate destruction of water facilities. 'Today's armed conflicts are essentially wars on public health,' comments Dr. Remi Russbach, the ICRC's Chief Medical Officer" (Poklewski-Koziell and Dorais-Slakmon, 1994, p. 10).
In these situations, the two aspects of water provision programs figure prominently. Water quantity is diminished or lost entirely due to breakdown of piping and pumps, or the loss or damage of water towers or other elevated sources. Secondly, even piped water sources may become contaminated due to damage to the system lines. In many urban areas water supply and sewer lines may lie side by side underground. When the lines are damaged, it is very possible that water supply sources can become contaminated from sewer pipes. This is especially so when water pressure in the mains fluctuates due to power failures. In addition to the direct threats of lack of water or water of poor quality, secondary urban systems may also be affected by lack of water pressure, including district heating in some urban centers, and even systems for factory and plant operations.
Urban water systems are complex. In all such cases the specialists best suited to correct the problems, and to repair and rehabilitate theses systems are those national or municipal engineers who have built and maintained the systems and who have access to and a working knowledge of the system diagrams, drawings, specifications, as well as its performance history. It is generally the case that in such instances what is needed most is money, equipment, and materials, rather than expertise.
In some cases, especially for hospitals and other critical urban facilities, hauling water from outlying areas has been required to maintain the functioning of key facilities. The Red Cross/Red Crescent, among others, have at times shipped, bagged and/or bottled water for such situations when need is extremely critical. In such cases the military, civil defense, or other large and well-funded organizations may be required to mobilize this type of cost and labor-intensive response.
Immediate response may typically include the installation of unitized local treatment units to clean polluted water supplies, or equipment to augment or replace damaged pumps. Additionally, the distribution of quickly dissolving water purification tablets (chlorine) for home use with container storage can be used. In situations of active conflict where repairs to centralized facilities may in fact attract further attacks and damage, it may be necessary to construct decentralized service points, such as wells with smaller pumps, and/or rerouting of water service to local distribution points.
13. Locating Appropriate Expertise
UNHCR is often the lead agency in determining which sewage management systems are best or most applicable to the situations involving refugee camps or other emergency settlements of refugees. This determination is made with or without the advice of local NGOs. UNICEF also has developed expertise in this field, although their aim is more developmental and less emergency-oriented. The minimum qualifications for consultants in this area, whether agency specialists or private consultants, should be that the individuals are experienced environmental health specialists, sanitary or environmental engineers.
The specialist hired for this task should be pressed into service from the outset of the emergency if possible to allow him or her to participate in the preliminary work/survey, such as identifying suitable sites for emergency settlement. From this basis the expert can better contribute to the development of these sites and help in the organization and management of programmes for the monitoring and surveillance of the quality of the settlement's environment.
14. Sustainable Steps in Implementing an Environmental Health Plan for Emergency Settlements.
The settling of people in an emergency situation will often take place while the site is being developed. Therefore, a sector-by-sector or block-by-block approach is recommended for such situations. This applies both at the household level as well as the community level for schools, markets, clinics, etc. The installation of different facilities for managing excreta disposal, domestic garbage collection, and wastewater drainage should start where physical conditions such as soil, and topography present fewest difficulties for the installation of the system "hardware". Also useful in determining where to start are the attitudes of the people in various sectors, their willingness to participate, and their awareness of the issues surrounding environmental health.
Designing a management scheme for the disposal of human excrement in large scale emergencies is critical. Improvements to the scheme should be approached incrementally, working towards small, lasting improvements that are sustainable at each step, rather than the wholesale introduction of new systems.
For a rapidly growing emergency settlement population there must be both a long- and short-term plan. The short-term plan must address the inevitable lack of time and resources but still adequately manage wastes without spreading contamination. The timeframe for the environmental sanitation response is usually climate dependent. It takes only about 1 week for flies to emerge from wastes in warmer climates. Therefore a good system must be put into place quickly. For a rapidly-settled emergency-displaced community, one such incremental sanitation plan might include (in chronological order) the following:
a) A site survey of its sanitary disposal needs must be conducted immediately.
All of the following steps (2-4) must be carried out in concert with a public awareness/education campaign on the proper use of the current system or strategy including the formation of environmental health committees to assist in the design, implementation, operation and maintenance of the systems.
b) Demarcate fields for controlled defecation areas and install temporary trench latrines (as deep as the soil, subsoil and water table will allow).
c) Next, (or simultaneously with # 2 if resources allow) construct a sufficient number of pit latrines for families (private family-held units) and for public facilities such as schools, markets, and clinics. Both types of latrines should be installed in such a way that they can be provided with ventilation (i.e. VIP latrines) at a later stage without having (for example) to construct new squatting slabs. In this respect and given the various nature of site specific constraints, the siting of these different facilities must be well thought through before the implementation of the latrine program.
d) Improve latrine facilities by transforming them into VIP, VIDPs (ventilated improved double pit), or pour-flush toilets if water is available, and the excess water is not deemed to be a problem for the proper functioning of the latrines. Small bore piped sewer networks are also appropriate where topography is favorable.
15. Planning for Emergency Settlement in Urban Situations
In urban situations served by piped sewer systems it can be assumed that approximately 1 liter of waste per person per day will be produced and will need to be removed or treated in the emergency settlement every day. This figure is exclusive of the water used to carry it. In the immediate response to an emergency situation, on-site sewage storage may suffice. However, off-site facilities will be required, either through trucking such wastes from holding tanks or carried away by water in piped systems. The repair and restoration of pre-emergency services is the preferable solution, even if inadequate in the very short term.
In many cases in urban settings people will be housed in public buildings and community facilities such as schools, churches, universities, gymnasia, stadia, community centers and so on. In such cases, previously functioning sewage systems may become quickly over-taxed and fail. Such facilities may already be using latrines or small localized systems not connected to the municipal sewerage system. In this case the waste holding facilities (especially the latrine pits) quickly become full, and overflow. This must be avoided at all costs. There are three options available:
a) abandon the over-stressed latrine facilities for newly installed units
b) initiate a system of routine pumping or desludging to keep (primarily) water volume down to a manageable level
c) convert pit systems to sewered systems by extending municipal systems to these facilities where topography and other concerns allow.
The "best practice" to recommend from these options can only be determined by site investigation into the costs, reliability, and viability of the various options proposed. As a generalized best practice, however, it can be said that planning immediately for the implementation of one or more of these solutions must be taken at the time the use of such facilities is identified as a response to emergency settlement.
16. Community Toilets Don't Work
In any type of system, rural or urban, wet or dry flushing, latrines or toilets should be assigned on a family basis wherever possible. These units must be easily cleaned, located, and identified as belonging to a particular family group. Only in cases of very short term, or transit situations can public toilet facilities be made to function well. This strategy should only be employed where there is no option for individual family assignment, or as part of community facilities such as schools and clinics. In any case, full-time maintenance is required.
17. Involvement of the Community in System Design and Management
All segments of the community-religious and political leaders, women, and other active or influential groups-should be involved in the design and operation of the emergency settlement's environmental health systems.
The community should be solely responsible for the operation and maintenance of its own environmental health systems. This will take training and time-up to a year. However, it should not take longer in order to avoid development of dependence on outside assistance providers.
As with environmental health services, health education must be integrated with other aspects: maternal and child care, immunization, family planning, nutrition and common sense use of curative care. It must start immediately, is often required to effect use of new types of water or sewerage disposal systems, and is critical in getting good solid waste disposal and vector control. Women should train women. Religious or community leaders must also be convinced of the need. Political will get almost anything done in cases of emergency settlement. NGOs such as IRC, ARC, CARE, SCF, and MSF have extensive backgrounds and experience in emergency health education.
18. Technology and Latrine Types
Although there are improved types of latrines now widely used (VIP and improved VIP for example), the final decision on which type to use and where they should be located should rest with an experienced professional who is knowledgeable in the community norms, local conditions, and environmental health, regardless of the expressed preferences of the community.
The following set or proposed standards incorporates the two headings Absolute Minimum Acceptable and Preferred Minimum. There are two reasons for this determination of multiple minimums. The first is the time element of applying the standards - the lower or Absolute Minimum Acceptable applies to those situations of short duration (a few days or two-three weeks), the Preferred Minimum applies to all other situations. The second reason is that while it is important to recognize the Absolute Minimum Acceptable standards listed, lessons learned from past situations have taught us that the Preferred Minimums proposed are in fact good practice, and should be held by implementers as the minimum acceptable standard of performance.
|Water Supply||Absolute Minimum Acceptable||Preferred Minimum|
|Water Quantity, minimum liters per person per day (l/p/d) - general population|
|Cold dry climate||8.4||18.7|
|Cold wet climate||7.9||18.4|
|Hot dry climate||11.8||25.3|
|Hot wet climate||9.7||23.4|
|Water Quantity, minimum liters per person per day (l/p/d) - hospitals|
|Cold dry climate||14.2||27.2|
|Cold wet climate||13.6||26.6|
|Hot dry climate||18.1||37.8|
|Hot wet climate||15.8||30.9|
|Water Quantity, minimum liters per person per day (l/p/d) - feeding centers|
|Cold dry climate||7.3||15.9|
|Cold wet climate||7.0||15.7|
|Hot dry climate||11.3||22.0|
|Hot wet climate||9.6||18.4|
|Water bacteriological quality||Absolute Minimum Acceptable||Preferred Minimum|
|Fecal coliforms, maximum per 100 ml water||31.0||0.0|
|Total coliforms, maximum per 100 ml water||53.0||1.8|
|Fecal streptococcus, maximum per 100 ml water||5.5||0.0|
|Heterotrophic plate count, maximum||1.0||0.0|
|Enterococcus, maximum per 100 ml water||20.0||0.0|
|Water chemical and physical quality||Absolute Minimum Acceptable||Preferred Minimum|
|Total dissolved solids, maximum mg per liter||2300.0||540.0|
|Salinity, as chloride, maximum mg per liter||475.0||41.02|
|Nitrates, as Nitrogen, maximum mg per liter||40.0||50.0|
|Fluoride, maximum mg per liter||2.4||2.4|
|Organics, including pesticides, max mg per liter||1000.0||1000.0|
|Turbidity, maximum NTU units||1.00||5.0|
|Excreta Disposal||Absolute Minimum Acceptable||Preferred Minimum|
|Depth of effective soil, minimum meters||1.0||2.3|
|Soil infiltration rate, minimum liters per square meter per day||21.0||67.0|
|Soil Type||clay or sand||loam|
|Depth to groundwater, minimum meters||4.1||13.1|
|Distance to wells, minimum meters||41.0||93.0|
|Distance to surface water, minimum meters||47.0||152.0|
|Distance to dwellings, minimum meters||25.0||50.3|
|Solid Waste Disposal - Landfills||Absolute Minimum Acceptable||Preferred Minimum|
|Soil infiltration rate, minimum liters per square meter per day||30.0||61.0|
|Soil Type||sand||clay or loam|
|Depth to groundwater, minimum meters||8.6||9.8|
|Frequency of covering, minimum days||4.4||1.0|
|Depth of soil cover, minimum days||0.4||0.9|
|Distance to wells, minimum meters||28.3||74.0|
|Distance to surface water, minimum meters||36.0||144.0|
|Distance to dwellings, minimum meters||217.0||366.0|
|Drainage||Absolute Minimum Acceptable||Preferred Minimum|
|Slope of entire camp, minimum percent||1.6||3.7|
|Maximum soil infiltration rate, liters/sq. m./day||77.0||100.2|
|Minimum soil infiltration rate, liters/sq. m./day||12.5||29.5|
|Elevation above 10 year flood plain, min. meters||2.5||5.7|
|Elevation above 100 year flood plain, min. meters||3.5||6.6|
|Vectors and Pests||Absolute Minimum Acceptable||Preferred Minimum|
|Distance to mosquito-breeding areas, min. meters||179.0||632.0|
|Distance to fly-breeding areas, min. meters||187.0||719.0|
|Distance to endemic pests, minimum meters||310.0||770.0|
|Absolute Minimum Acceptable||Preferred Minimum|
|Distance to noise sources, minimum meters||190.0||350.0|
|Distance to natural polluters, min. kilometers||9.6||18.0|
|Distance to transportation routes, min. kilometers||2.4||3.8|
|Distance to industrial zones, min. kilometers||1.8||3.9|
* Information in this table is adapted from "Developing Environmental Health Criteria for Locating and Assessing Disaster Relief and Refugee Camps, Using a Multi Attribute Utility Rating Technique" - G. Shook, Dissertation Dec. 1990. Published Elsewhere
Environmental sanitation guideline standards
P.O. Box 13
06561 Valbonne Cedex
(water supply and sanitation)
World Health Organization
P.O. Box 926967
(All aspects of environmental health, with emphasis on water supply and sanitation - CEHANET information system)
Lima 100, Peru
(all aspects of environmental health - REPIDISCA information system)
Apartado Postal 105.34
Mexico 5, Mexico
(Human ecology, health aspects of environmental pollution)
1611 N. Kent Street, Suite 300
Arlington, Virginia, 22209-2111
(water supply, sanitation, environmental hygiene)
Asian Institute of Technology
P.O. Box 2654
(Emphasis on water supply and sanitation, environmental engineering - SENSIC database)
9 King Street
London WC 2E 8HN
(low cost appropriate technology, emphasis on water supply and sanitation)
P.O. Box 93190
2509 AD, The Hague
(water supply and sanitation)
The Director - Institute of Civil Engineers
1 Great George Street
(specialists in engineering support for water and sanitation systems for emergency response)
London School of Hygiene and Tropical Medicine
London WC 1E 7HT
(environmental health, water supply, sanitation, vector control)
P.O. Box 30552
(environmental pollution, overall aspects of environmental protection)
7, Place de Fontenoy
75007 Paris, France
Centre for Documentation of Refugees
Case Postale 2500, CH-1211 Geneva 2 Depot
(PTSS provides expertise in water and sanitation and other aspects of environmental health for refugee camps and other situations requiring external assistance)
Loughborough University of Technology
Leicestershire LE11 3TU UK
(training in water supply and sanitation issues)
Division of Environmental Health
1211 Geneva 27, Switzerland
(all aspects of environmental health)
1818 H Street
Washington, D.C. 20443
(water supply and sanitation, waste disposal)
Auerbach, P.S. and E.C. Geehr. 1989. Management of Wilderness and Environmental Emergencies. Mosby.
Benenson, A.S., editor. 1990. Control of Communicable Diseases in Man. APHA.
Canadian Department of National Health and Welfare. 1979. Emergency Health in Disasters.
Chalinder, A. 1994. Good Practice Review #1 - Water and Sanitation in Emergencies. Relief and Rehabilitation Network.
Feacham, et al. 1980. Health Aspects of Excreta And Sullage Management: A State of the Art Review. World Bank
Franceys, R., F. Pickford and R. Reed. 1992. A Guide to the Development of On-Site Sanitation. World Health Organization.
Ockwell, R. 1986. Assisting in Emergencies: A Resource Handbook. UNICEF.
Poklewski-Koziell and Dorais-Slakmon. 1994. "No Life Without Water", Red Cross, Red Crescent 3:8-10.
PTSS. 1992. Water Manual for Refugee Situations. United Nations High Commissioner for Refugees.
Rakotomalala, C. 1994. "Environmental Health Management in Refugee Camps" in Proceedings of the Regional Workshop on Environmental Health Management in Refugee Areas, Pakistan. WHO Technical Publication, pp. 38-47.
Shook, G.A. and A.J. Englande. 1992. "Environmental Health Criteria for Disaster Relief and Refugee Camps." International Journal of Environmental Health Research 2(2):212-220.
Turner, J. Ellis. 1991. Environmental Health: Water, Sanitation, Wastewater Management, and Drainage. Water and Sanitation for Health Project - USAID.
USAID/OFDA. 1994. Field Operations Guide for Disaster Assessment and Response.
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