Draft Development Strategy, National Water Management Plan
Arsenic in Annex L3.3 Arsenic ContaminationA detailed assessment of the current situation regarding the incidence of arsenic in groundwater and the probable causes is presented in Annex C Appendix 8. This discussion summarizes the situations and focuses on the implications for drinking water supply.The current Bangladesh water quality standard permits arsenic up to 0.05mg/1. This is five times higher than the WHO guideline of 0.01mg/l. Factors affecting susceptibility to arsenic poisoning are not yet well understood, with different people sharing the same contaminated source showing different levels of symptoms or none at all. The long - term trend will probably be to move towards the WHO guideline value. In the shorter term, use of a higher threshold of contamination will help to define the areas for priority action. Arsenic was first found in high concentration in groundwater in random screenings of HTWs across Bangladesh. Testing for arsenic was initiated because of awareness of arsenic problems in neighboring West Bengal and the medical diagnosis of arsenic poisoning in some patients. ‘Hotspots’ were identified as a result and more testing conducted in these acutely affected regions. The full extent of contamination is not yet known and will not be known until full screening of all HTWs is carried out using reliable test kits. However, estimates as a result of continuing broad based testing suggest that people living 60 of 64 Districts in Bangladesh may be affected by arsenic contamination to some degree. As a result of initial investigations, arsenic in extremely high concentrations was found in groundwater pumped from HTWs and DTWs in parts of the South West, the extreme North East, in isolated ‘hot spots’ along the Ganges/Padma river, in large swathes of the South East, and in some areas near Dhaka (Figure 3.1). In some places, up to 2.4mg/l of arsenic, approximately 250 times the WHO standard (0.01mg/l) or 50 times the Bangladeshi standard (0.05mg/l) was identified. Not all wells are affected: fewer than half the wells tested to date have contained arsenic above the WHO guidelines. The concentration of arsenic in groundwater is highest between about 20m and 60m depth and the risk of it occurring in groundwater below 200m is low. Since the detection of arsenic and recognition of the potential hazards to public health of ingesting arsenic contaminated water, public health engineers and medical experts have realized that a radical shift will need to take place in the way in which safe and affordable domestic water supply is provided in rural Bangladesh. To date, the crisis appears mainly to affect rural communities. However, shallow tube wells in urban areas are also affected. Urban piped systems may be affected if the DTWs supplying them draw water from a contaminated aquifer. 3.3.1 Population at RiskEstimates vary as to the number of people at risk from arsenic poisoning, though the situation is critical. One report suggests that nearly 70 million people are likely to be affected by arsenic contamination of shallow tube wells. Until comprehensive tests of all STWs (HTWs and irrigation wells) are completed and entire communities screened, however, the actual number of people at risk from arsenicosis will remain uncertain. Detection of arsenic in HTWs and emergency measures have been the priority to date. The areal extent and degree of contamination of existing drinking water sources is believed to be considerable, however, and as resources are limited the impact of these measures has been low. In an initial study conducted by Dhaka Community Hospital (DCH), Ministry of Health and Family Welfare (NIPSOM) and School of Environmental Studies (SES), Calcutta, tube wells in 27of 38 Districts in Bangladesh were revealed to contain arsenic above the GOB pemissible limit of 0.05mg/l. The percentage of arsenic - contaminated tube wells in Nawabganj, Pabna, Faridpur and Laksmipur in that study was found to be higher than anywhere tested in the previous ten years in West Bengal, a factor signalling the potential severity of the problem in those Districts. Figure 3.1: Maps of Arsenic Contamination [Click inside for full view]
Since the detection of arsenic in groundwater, testing of wells has been complemented by epidemiological surveys. Laboratory analyses of hair, urine and nail samples taken from people with symptoms of arsenic poisoning (skin lesions and the thickening of the soles of the feet and palms of the hand) have revealed very high levels of poisoning. Not all those who drink contaminated water develop arsenicosis however. Scientists attempting to determine the factors which affect the susceptibility and resistance of people to arsenic poisoning have concluded that good nutrition may be a significant factor. People whose nutritional status is poor will tend to develop skin lesions while better-fed people will not, an indicator that one strategy to combat arsenicosis might be increased consumption of nutritional supplements such as Vitamin A28 or antioxidants such as Vitamin E. Leafy vegetables upon which many Bangladeshis rely for daily nutrients are suspected of absorbing arsenic and therefore, are no longer recommended for arsenic patients. As understanding the degree to which arsenic enters the food chain is crucial for developing long - term arsenic mitigation and nutritional improvement strategies in Bangladesh, two types of related research have recently been undertaken. The Australian Center for Irrigation, Agriculture and Research (ACIAR) is investigating evidence of arsenic entering the food chain while FAO is conducting a study in Bangladesh to determine the possible effects of arsenic on stunting rice stalks and reduced rice yields up to a possible 20% of total production. However since crops are already being irrigated with water containing arsenic, such yield reductions would already be occurring and are not likely to cause a drop in future production. 3.3.2 Hot SpotsThe composite mapping of findings in June 2000 of village ‘hotspots’ by Thana undertaken by the Emergency Task Force of the local Consultative Group (and based on the DFID/BGS studies, the UNDP 200 village survey, the UNDP/WB 500 village survey, BAMWSP, UNICEF, JICA, DANIDA/DPHE, NGO Forum, DPHE/DFID and the WATSAN partnership data) confirmed that clusters of highly affected Thanas are found along the western border of the South West, large areas of the South East, the extreme North East, spots North East of Dhaka along the Meghna, and at points along the Ganges/Padma. More specifically, the swathe of most affected Thanas spans some, but not all, of the western-most Thanas of the South West around Jessore, the riverine areas near Rajbari and Faidpur, southwards to Nagarkanda and Muksudpur, a concentration near Santhia, Sujanagar, and Bera on the left bank of the Ganges/Padma, parts of the South East near Lakshmipur and Chandpur, and a smattering in the north eastern-most Thanas including Zakianj, plus areas near Sonargaon and Raipura along the Meghna. Various agencies conducting surveys using a variety of test kits have recently published individual findings as well. NGO Forum through its regional offices has tested a total of 11,279 samples and found arsenic above 0.05mg/l in 2668 (less than 25%). Of 2882 villages, arsenic was found in 782 wells at a concentration ranging from 0.10 to 1.70mg/l. In one of the earlier studies, DCH found arsenic above 0.01mg/l (WHO standard) in April 1999 in 142 villages of 24 Districts. UNICEF claims to have found arsenic contamination in 211/460 Thanas at a concentration of 0.05mg/l, roughly in 29% of all wells. Grameen Bank members tested 17,902 wells in Chandpur District by March 2000 and found 98% of wells to be contaminated. (In one Thana in that District, no green tube wells were found in the 119 villages surveyed so the proposed strategy of asking women to seek water from neighbors would not be possible in those areas). Ponds were not deemed an appropriate or acceptable source so in that case, dug wells were provided. Communities in the main opted for DTWs. At the 3rd DTW sponsored conference on arsenic in May 2000, it was estimated that only 5% of hand pumps in Bangladesh had so far been tested so the state of knowledge was far from complete. Agencies who continue to be involved in the testing as of June 2000 include DANIDA/DPHE, BAMWSP, JICA, the WATSAN partnership, UNICEF, plus Dhaka Community Hospital, NGO Forum, BRAC and Grameen Bank. 3.3.3 Social and Health Impacts of Arsenic ContaminationChildren, in particular, are at high risk from arsenic exposure, especially if they are poor and malnourished. In one village, more than 55% of children under ten years of age drinking water containing 0.84mg/l of arsenic showed arsenic - induced skin lesions. These children were all poor and ill - nourished. As a large number of women and children under five suffer from severe or moderate malnutrition, the number of persons at risk may be underestimated. A random examination during a field survey in 18 of the 34 Districts where arsenic contamination was suspected found 57% of people to have arsenic lesions. Researchers believed that only 10 - 15% of those suffering from arsenicosis had come forward at that time and been formally diagnosed. Many ‘patients’ do not come out to be examined, fearing isolation if their disease proved to be contagious, and young women in rural communities do not wish to be examined by male doctors. They are also afraid of being deemed unmarriageable if found to have skin lesions. Arsenicosis is connected in local people's minds with HIV/AIDS or leprosy and as a result, patients are treated as pariahs. Women have been divorced on the basis of having arsenic lesions and patients are being refused water from arsenic-free wells. Subsequent surveys are helping to compile a gender - based profile of patients and ascertain factors contributing to the development of asenicosis. The UNDP/DCH 497 village survey identified 2327 patients (59% rnale/34% female) in villages, which were comparatively more affected by arsenic. A survey of 37,239 people in flood-prone, plains and hilly zones in 1999 revealed a predominance of male patients (the number was not named) and the majority of tube wells affected by arsenic were in flood prone areas (42% of wells contained arsenic above 0.01mg/l and 23%>0.05mg/l). This result is supported by another study, which found 54% of patients to be male and to be in he range of 10 - 40 years old. That study concludes that 35 million people, mostly in rural areas, are at risk of arsenic toxicity. In the course of five years, DCH analyzed 22,003 HTW samples in which they have found arsenic levels above 0.01mg/l in 54 and over 0.05mg/l in 47 Districts. Groundwater containing arsenic above the Bangladesh standard was found in 918 villages. So far DCH has identified a total of 3688 patients in 30 of 32 Districts surveyed. From a total of 11,000 hair and skin samples, (50% from those with lesions, 50% from those without) researchers have determined that 90% of people tested have a level of arsenic in their hair, nails and urine above the normal level. In affected areas, some people suffering from arsenic lesions have since died from cancer and gangrene. The World Health Organization estimates that exposure to arsenic over a period of five to ten years can produce symptoms of keratosis and over a lifetime, can lead to cancer. Selenium, an element, which can combat the effects of arsenic and is present in eggs, milk and a few other food stuffs has been found to be notably missing in post - mortem examinations of the livers of arsenicosis patients. The absence of selenium can be attributed to the depressed purchasing power of the rural poor, though not enough is yet known to assess the impact. 3.3.4 Arsenic Mitigation: Strategies and ImpactsDhaka Community Hospital (DCH) which has sponsored three international conferences on arsenic in 1997, 1999 and 2000, has been actively engaged in alerting the public to the wider health implications of arsenic poisoning. With assistance from UNDP, DCH was involved in testing wells, detecting arsenicosis patients and raising awareness of the problem in conjunction with Ministry of Health and Family Welfare (MoH) through the Rapid Action Testing Programs. As The disease initially was largely unknown to doctors, DCH was also involved in training medics and health workers to diagnose symptoms of arsenicosis, with support from OXFAM and other NGOs. In January 1999, a multi - media communication campaign was commissioned by DPHE/UNICEF to raise awareness of the arsenic problem. In February 1999, a Government conference on arsenic, mitigation took place and UNICEF took up an integrated 'action research' arsenic mitigation program in four Thanas (500 villages approximately) with associated NGOs, to test and analyze existing water sources, provide safe alternatives and investigate health impacts. In August 1999, UNICEF supported DCH to expand the scope of their program using an integrated and comprehensive community - based strategy. Other innovations were tested as well. A pilot treatment plant for arsenic removal was installed in Tungipara (Gopalganj) and the Swiss Development Corporation (SDC) funded the WATSAN project in Rajshahi and Chapai Nawabganj to test the efficacy of solar - assisted oxidation and sterilization of groundwater. In 1999, DFID in conjunction with the British Geological Survey completed Phase II of its hydrological study on the origin and extent of arsenic contamination following its Phase I systematic survey of more than 3000 wells. DFID with DCH is now developing a health/nutrition/epidemiological study with arsenic mitigation in six areas, in addition to a water and sanitation field implementation project with DPHE/UNICEF. Other donor - sponsored projects implemented to facilitate arsenic mitigation include the development of treatment technology (CIDA and AusAid), test kit development (JICA and WHO), further related studies (USAID, GTZ, and FAO) hydrological investigations (IAEA) and screening, and development of alternative sources (Rotary International). The Netherlands Government also piloted arsenic removal techniques for piped water systems and community awareness in Paurashavas under the 18 DTP. Testing of HTWs for arsenic to date has then highly localized and targeted towards known areas of high arsenic contamination. It has also been relatively time consuming and expensive. A major problem has been that some agencies only undertake testing of the tube wells they have financed and installed. Because of the critical situation, many consumers wish to know if their individual, often privately financed HTWs are contaminated by arsenic. However, several years after acknowledging the problem of arsenic contamination, it is still not clear how they will obtain equal access to test kits or arsenic removal facilities.Field test kits used since the start of the investigations have not been entirely reliable. Moreover, they were not able to determine arsenic content at relatively low levels (i.e. between 0.01 and 0.05mg/l). General Pharmaceuticals Ltd (GPL) have recently stopped production in January 2000 due to poor reagent quality. They are now importing the reagents from MERCK BDH England and have sent the reagents to the National Science Laboratory for validation. Water Aid will he procuring a small number of these GPL kits and cross - checking their field results with both the Arsenator and the laboratory. In some areas, a faster, more sophisticated and more expensive instrument known as an ‘Arsenator’ is also being tested. Comprehensive testing of all wells including irrigation wells formed the first component of the GoB/World - Bank/Swiss Development Corporation funded Bangladesh Arsenic Mitigation Water Supply Project (BAMWSP). This is proceeding but results of testing were not available for this report. Under the BAMWSP project, a three-tier monitoring and testing strategy is also being established in order to provide support in the long term to quality control of the monitoring process.Various mitigation strategies have beat implemented to date on a pilot basis, but again, often only in areas where the contaminated tube wells have then paid for and installed by Government and donor agencies. In areas where arsenic was detected and tube wells marked red, initially people were advised to drink water from other sources. Field workers encountered resistance to this at local level, however, and many continue to drink from untested wells. DPHE/UNICEF have provided pond sand fliers (or DTWs where possible). DPHE/DANIDA arsenic mitigation projects installed alum based treatment tanks in Noakhali initially but are now concentrating on installation of DTWs in those peri - urban areas previously provided with hand pumps under their program. Other donors have set up emergency pilot schemes to distribute filters and test their efficacy along with other modes of treatment. The Khan three kolshi method is currently under test by BRAC and Water Aid. DCH has suggested modifications of this traditional method, which entail using iron chips, coarse sand, wood charcoal and fine sand.Initial testing of the locally made Shafi filter indicated that arsenic was removed from water between 0.5 to 0.05mg/l and made water safe in 97% of cases, however, field evidence showed that this result could not be sustained. The filter is now undergoing modification. Various technologies used for arsenic removal are being subjected to controlled testing by independent authorities before widespread replication. The Government based Technical Advisory Group (TAG) has only approved one arsenic removal technology to date, however: the three kolshi method. They advocate use of ‘alternative sources’ pond sand filters, rainwater harvesting, DTWs and hand dug wells. To assist in the long testing and verification process, Water Aid undertook preliminary field testing and consumer assessment of household arsenic removal methods. They concluded that passive sedimentation (i.e. storage of water for 12 hours+) was not a ‘universal’ solution since bacteriological contamination increased substantially and arsenic content was not reduced below 50mg/l. The two bucket treatment (as developed by DANIDA/DPHE) and under test by DCH, WATSAN Partnership, BAMWSP and Water Aid) was shown to reduce arsenic content by 81 - 90% but not below 50mg/l. A variant on this using locally procured phitkiri or alum was also tested and proved very popular with women. It similarly reduced arsenic content but not to the standard required in all cases. The Shafi filter, on the other hand proved to be unpopular with consumers as it produced only 12 liters of water per day, (insufficient) for domestic purposes) and was too law to be practicable for daily needs. At Tk1000, it was also seen to be far too expensive for most households.It is clear that even if proven successful and manageable at local level, arsenic mitigation treatments may be difficult to replicate or sustain beyond the emergency phase. Most will require monthly purchase of chemicals and regular testing of the filtered water to ensure quality, so local availability and price may be crucial. BAMWSP was advocating treatment of contaminated water at household level using freely distributed buckets, alum and chemicals but monitoring of household treatment using alum and potassium permanganate revealed a tendency for women to use an excessive dosage of chemicals, so creating a new health hazard. Widespread use of this method is now being discouraged. UNICEF-sponsored VERC/WATERAID pilot projects have also been providing filters and arsenic removal kits free of cost to test mitigation strategies. In areas of acute arsenic contamination, DPHE/UNICEF have installed DTWs, (each costing Tk45,000) free of charge and during the Flood Rehabilitation Program 1998 - 99, more DTWs have been installed as part of emergency relief operations. For several years, rainwater harvesting tanks have been provided in the coastal belt areas by theWorld Food Program and other agencies. These actions though justifiable from a humanitarian point of view, will not engender a desire in communities to contribute towards the capital investment cost of pond sand fitters, DTWs or filtration systems in the long term.The private sector is also attempting to respond to the demand for affordable and reliable arsenic removal equipment. Two solutions which might be applicable at the community level are first a packaged filter unit capable of running at 5m3/hour being developed by the University of Connecticut. This filter would have to be replaced every nine to 12 months and the final costs have not yet been estimated. The second is a filter unit suitable for use with a hand pump. The Stevens Institute of Technology has also introduced a bucket filtration system using tablets to be made locally. These technologies along with all the others are subject to formal approval by TAG before they can be produced and disseminated. The Stevens’ filter is currently undergoing field testing but has not yet been granted approval.The National Policy for Safe Water Supply and Sanitation (NPSWSS), passed in November 1998, requires cost sharing be introduced as part of a new approach to sustainable water supply provision. This policy was largely formulated and signed prior to an understanding of the potentially catastrophic dimensions of the arsenic problem and revised estimates of the population affected. However, its orientation reflects changing consumers’ perceptions about investment in household infrastructure. Unfortunately, it has become clear that most communities are nor willing to invest in arsenic mitigation strategies. Experience from Pakistan, Yemen and Egypt, however, indicates that communities probably would be interested in investing in technologies which improves their access to water in the household and would not be affected by seasonal shortages.The only known direct treatment for arsenicosis is to drink and consume water from an arsenic-free source. It is possible that arsenic poisoning may be reversed, and in West Bengal as well as Bangladesh, many people previously showing diffuse melanosis or symptoms of earlier pigmentation associated with arsenic poisoning have returned to normal life after drinking safe water, eating nutritious food and doing some daily exercise. One option which is under trial and might be efficacious is the distribution of vitamin-enriched dietary supplements and anti-oxidants to arsenic patients, though the impact is not yet known. At the moment, most of the eleven million HTWs have not been tested so individual households are not sure if their source is contaminated or not. This is an unsatisfactory situation and one which needs to be tackled in a pro-active manner. Safe water sources are available. Current information indicates that groundwater from depths greater than 200rn is almost always free of arsenic. While a limited number of deep wells have been shown to be arsenic contaminated, these may not be drawing water only from a safe depth. In saline coastal areas, where arsenic may also be present, there is a concern that the deep aquifer could be contaminated if DTWs were dug which punctured the sealing layer between the deeper fresh water aquifer and the layer above which is saline. Other solutions for providing water supply may need to be found in these areas for the long-term. The task of the National Arsenic Mitigation Information Centre (NAMIC) established under BAMWSP is to collect, manage, interpret and disseminate all relevant hydro-geological, water quality health, socio-economic and technical information necessary for the Project Management Unit so as ‘to devise strategy and priorities, develop an action plan and monitor progress in arsenic mitigation. BAMWSP is to test a range of pilot schemes in six Thanas to be replicated in 60. Additionally, in collaboration with others in the sector the project is to review the results of mitigation trials and help to co-ordinate a coherent and comprehensive strategy for dealing with the arsenic problem.3.3.5 The Socioeconomic Context of Arsenic MitigationAlthough the dimensions of the arsenic problem in Bangladesh are enormous, public awareness of the overall extent of arsenic contamination has been limited. It has also been difficult for arsenic mitigation projects to reverse the consumer trend towards urbanization and self-sufficiency epitomized by shallow tube well technology. Low cost piped water supply would constitute the next progressive service tier, in that it would supply running water in the bari and so supplant the use of hand pumps. From field studies of attempts to persuade consumers at risk from arsenic poisoning to adjust to new technologies, several behavioral trends have so far been identified. If a safe source is distant or situated in a site of potential conflict (a neighbor’s house, for example), women tend to revert to collecting and drinking water from the contaminated source, despite all warnings. Women are also noticeably reluctant to abandon their private source and adopt a community-based resource that will be difficult to maintain and may not provide safe water throughout the year. Arsenic contamination of drinking water supply has been discovered at a time when many low-income households have invested extensively in private hand operated tube wells (HTW's), which pump from the shallow aquifer. A safe domestic filter may prove acceptable to consumers in the short term as a means of redeeming the investment but probably only as a short-term mitigation option. Women are responsible for undertaking arsenic treatment in the household as part of their domestic tasks. Field studies conducted by DANIDA/DPHE indicate that even in affected areas, they need to be specifically encouraged to pursue this task through interpersonal communication and house- to- house visits. Findings from 18 DTP indicate that women do not understand the tube well color markings, as the notion of green=positive, red=negative is not familiar to them. Iron content in tube well water (which is bothersome but not lethal) is also being confused with arsenic poisoning. Having been weaned away from surface water sources, which were deemed to be the source of water-home disease, women associate dangers arising from consumption of unsafe water with diarrhea. Field workers have found that it was very difficult for women to accept or conceptualize the problem of arsenic poisoning for that reason. In addition to the relative absence of information on the dangers of arsenic and the risk of arsenicosis, a credibility gap has developed amongst consumes. In many communities including those in which arsenic has been detected, people do not believe that arsenic (since it is colorless and odorless) has poisoned the water source and will induce life-threatening illness. There is also a common perception that arsenic ingested in small quantities will not hurt anyone (especially if no lesions are visible) and therefore, drinking the contaminated water will not have a negative effect on health in the short term. Evidence from some screenings indicates that people in arsenic affected areas have a higher percentage of arsenic in the body than normal so this perception will need to be vigorously reversed through media campaigns and information dissemination. New investment in alternative sources may also prove difficult for rural consumers. The 1998 flood created a crisis of indebtedness in many parts of the country from which many people may not have recovered. Affected people may be unwilling or unable to take on further loans at this juncture unless more lower-cost, long term credit is made available for housing improvements which would include upgrading of water and sanitation facilities. There has been a mixed response to cost-sharing from GoB and NGO water sector providers. Consumers say that this ‘plague’ or ‘poison’ in the drinking water is not of their own making. They argue that since the government advocated drinking from wells, the Government should take full responsibility for the cost of arsenic mitigation. Communities will welcome access to arsenic-free supplies through improved sources such as piped supply and be more likely to contribute to investment in these than in others, if it is afordable. In the meantime, it is that that several factors will increase the risk to the public of arsenicosis. No comprehensive and extensive media campaign directed at rural users has been undertaken by the GoB to acquaint the public with the range of issues surrounding arsenic contamination. Recent experience shows, however, that media campaigns alone may not he sufficient to prompt behavioral change Pre-testing conducted by UNICEF of proposed TV spots on arsenic contamination, indicated that non-literate respondents had different understandings of the spots advising them not to drink from tube wells marked red and in the instances where B&W TVs were used, misunderstood one of the important messages. The difficulty of designing messages to broach the comprehension gap between literate and illiterate, and enlighten rural people as to the risks involved in drinking tube well water, will require extensive field study and community consultation (prior to materials’ preparation) if these television campaigns are to be successful. Several factors are already known to influence the acceptability of the arsenic mitigating option to rural communities. For outside sources, perceptions of the quality and taste of water from antiquated surface water sources, their physical ability to carry sufficient quantities from source to home and their safety in moving back and forth to the water source daily are among the reasons women are reluctant to adopt these sources. Household filtration techniques rated positively by rural women include those which resemble traditional filtration and water purification techniques (used during flood), are low cost, easy to use, the additives are easily available, and the temperature of the filtered water remains acceptably cool. Provided these remove arsenic and have no ill effects, these low cost solutions could be encouraged over the short term. To ensure acceptance of these methods over the longer term, however, is difficult. Programs will need to involve women in discussions of the merits of alternative water sources, interim household arsenic mitigation treatments and the planning, operation, management and monitoring of new and better systems concurrently. To date, NGO workers have been predominantly male and therefore unable to make contact with village women. To ensure that information reaches women and women's views are taken into account, more women will clearly need to be employed by NGOs, Government agencies and water supply providers to spur on development of more progressive water supply systems and the arsenic mitigation efforts. 4. Rural Water Supply4.2 Issues for Rural Water Supply4.2.3Overview of Current Arsenic Mitigation Emergency OptionsInternational agencies introduced tube well technology to Bangladesh and created a huge consumer demand for hand pumps. If as predicted, 11 million hand pumps have been procured the consumers who have purchased those hand pumps are at risk as are those who have received subsidized tube wells from donor or Government agencies. Consequently, information on emergency mitigation and supply of safe drinking water needs to be provided to all those affected, or at risk. Donors have responded to date with pilot mitigation projects in selected areas. Techniques tried out include physical coagulation, addition of resins and use of solar energy. The options tested to date include DPHE/DANIDA supported small arsenic removal units in Noakhali and Lalkshmipur involving use of alum (phitkiri) (and potassium permanganate) in small (2m3) closed box community tanks (cost of tank: Tk15, 000 and O&M cost, Tk 10/family/month), the domestic Shafi filter (UNICEF sponsored VERC and Water Aid project in Sitakunda (Chittagong); the use of precipitated ferric oxyhydroxide in well-head treatment tanks under a three-year New Zealand funded pilot project in Chapai-Nawabganj (Rajshahi) and an Australian funded project to test sunlight-enhanced removal of arsenic from tube well water. For surface water purification in areas of arsenic contamination, BRAC, Grameen Bank and OXFAM have approved the ‘five kolshi’ filter and tested the use of ring wells. The ‘three kolshi’ filter has also been approved for domestic removal of arsenic. These techniques are however, emergency measures and by their very nature will not deal with the long-term problem of supplying safe water to the rural population. Research and development of pond sand filters for coastal areas of Bangladesh was undertaken in 1984 by DPH/UNICEF. In areas of severe shortage of portable water, they have been successful but the main O&M limitation is that the top layer of sand must be cleaned extremely frequently by community members for the water to be potable. Feasibility studies have been undertaken to investigate the acceptability of pond sand filters in arsenic contaminated areas by LGED and MoH. If tube well water is used to fill the pond, disposal of the arsenic-bearing sand poses a long-term environment hazard. Current disposal techniques include burying the sand in dung and disposing of sand in latrines. Initial evaluation of pilot pond sand filters have indicated a public reticence to adopt such alternatives wholeheartedly. Community managed systems which encourage public access to drinking water are not normally preferred to privately managed sources such as HTWs but may become more acceptable in emergency situations. In recent field studies of options, rural consumers indicated that a shift to surface water sources would represent a step backwards in the progression towards urbanization of infrastructure. In resource terms, pond systems require considerable land acquisition, the purchase of expensive plastic linings and fences to ward off live stocks (though as been proposed, suitable public or khas land could be donated from school yards in every village. Water collectors are also required to pump water into the filter before filling their container (so that the next user does not have to wait for the water to filter through the system) and this would be expected to create bottlenecks in densely populated rural areas. In arsenic contaminated areas, there is also considerable resistance to abandonment of HTWs on the grounds that they contain arsenic. To some consumers in those areas, the fact that the water which appears clear and pure may contain carcinogens is not credible. From field studies it appears that there is considerable reluctance to revert to surface water systems. If ponds are to be selected as the favored option, information campaigns will need to be launched to persuade consumers that they must switch from HTWs to ponds (the former source of diarrheal disease) and stop using tube well water for a variety of domestic tasks. This has proven difficult to date. Cost recovery of the capital cost of pond sand filters is also likely to be limited since the public would need to be convinced of the value of this system. Precedents have been created by DPHE/UNICEF 1998 and NAMIC 1999 who provided new community ponds free of charge. (In some cases, land is to be donated by the community but in the NAMIC case, land acquisition comprised a major cost of the invention). Willingness to pay would depend on the ability of the local elite to mobilize support for this option. Women could be preferentially employed in managing these systems at community level (as elsewhere) especially if these schemes were adopted. Since they are the main users, this would constitute a managerial and O&M advantage.A pond of 0.5ha and 2m deep would be sufficient to provide 12.5 litres/day for 2000 people, when allowance is made for evaporation. On this basis 50, 000ha of ponds would be needed for the total rural population of 100M, although not all regions would need such a solution. One constraint is that ponds have to refilled during the monsoon season is unlikely to be sufficient to refill a deep pond. If monsoon season rainfall is 2000mm and dry season evaporation is 1, 000 then the available water in the pond is effectively only 1000mm unless other surface water is used to fill the pond, with associated risks of pollution. A pond of 0.5ha would need at least six sand filtration units to serve the target population. Smaller ponds, each with one sand filter, are an alternative which would be more convenient for the community but less feasible because of total land take. Furthermore, 12.5 liters/day meets very basic needs for drinking and cooking. Other sources would still have to be maintained and used to supply water for other uses. In sum, pond sand filters are a short term mitigation strategy requiring considerable subsidy, and one which is to gain much currency amongst rural women who are the main users.4.3.3 Rainwater HarvestingRainwater harvesting has also been advocated and developed by DPHE/UNICEF for use in the coastal Districts since 1994. Under their system collection is made from tin rooftops or a sheet of plastic into large cement tanks where it can be stored for use in drinking and cooking throughout the dry season. In areas where groundwater is saline, WFP and several other NGOs have distributed rainwater catchments tanks free of charge. This precedent will create difficulties for future cost recovery. In social terms the management of the system is home based and so widely are relatively low and the water is of suitable quality. Such boreholes would be cheaper since they are within the capability of hand drilling. In many areas of arsenic contamination, however, boreholes to a depth of a least 200m will have to be sunk. Theses can be within the capability of hand drilling provided the diameter is small. Otherwise they will require different and more expensive technology. The water level in the deep aquifer is effectively controlled by the water in the aquifer above, so it would not be necessary to pump water from the full depth.In non-arsenic areas, the same pump technology could be used where seasonal draw down of groundwater renders suction mode hand pumps unusable and would provide a cheaper and more acceptable alternative to the versions of Tara pump now provided in such circumstances. Either the mini-Tara (or improved equivalent) pump can be used in conjunction with existing wells or, if new wells are constructed, these would only need to be dug deep enough to ensure sufficient supply of water. The output from a force mode hand pump would be lower than for a suction mode pump, because of the increased effort required to raise water through a greater distance and could cause hardship to women operators. There are some parts of Bangladesh, particularly the South East, where groundwater irrigation is limited and the static water level in the deep aquifer remains within the suction limit. Consequently it is feasible, in these areas, to use the No 6 hand pump with a DTW instead of a force mode pump. However, given the high cost of a DTW and the low yield of a No 6 pump, this solution has very high per capita costs. 4.3.5 Piped Water Supply from DTWsPiped water supplies from DTWs fitted with electric pumps are a solution which would vary in scale and cost, depending on the size of the community to be served. Larger systems would save borehole and pump configurations similar to those used for urban water supply. Distribution systems could be more expensive because of the larger areas to be served for a given population. However, the cost of a conventional system using a 10/s pump to serve a community of 2000-3000 people would be in excess of Tk 1.5M or about Tk 750 per capita. The boreholes are also relatively expensive because they have to be drilled mechanically. An alternative approach would be to use much smaller pumps: A l/s pump would need a smaller, and therefore cheaper, borehole and could provide a community of about 1000 people with an average of 50 /c-d. This would be much easier to organize for operation and maintenance, compared with a larger system. Piped water systems, if well-managed and funded by public subscription, would guarantee a more constant supply of domestic water than any other. In the 18 DTP, customers found that they could economize on water wastage under a metered supply and so pay a cheaper flat rate so metering would be advised under this system to ensure coverage to low-income households. There are several choices for borehole based pipe systems to be used by communities. One is to distribute the water to storage tank/standpipe units (the 4.3.7 Domestic Filtration or TreatmentSeveral different approaches have been developed for household filtration and treatment of surface water to remove faecal pollutants. Oxfam and Disaster Management Unit have introduced the three kolshi and five kolshi domestic filter system to remove pathogens and iron to make water more palatable and safe for drinking. However, these filters do not remove arsenic. The Shafi filter and arsenic removal tanks are being tested by various government and non-government agencies including Water Aid, UNICEF, and Dhaka Community Hospital. These filters are reputed to be about 95% effective in removing arsenic using alum (phitkiri) using the one (or two) large plastic bucket The problems of environmental pollution arising from the disposal of arsenic sludge in areas of contamination and long term sustainability of the option remain unresolved, however and are under investigation. Treatment using alum requires time consuming stirring as part of the process and is unlikely to be sustained over long periods though the pilot treatment involving potassium permanganate requires only three minutes stirring. Another hindrance to take up is the time required for filtration (eight hours for nine liters of safe water) although the alum (aluminium sulphate) treatment is faster. Results show that efficacy and safety of the treatments advocated depend to a large extent on the increased awareness of householders, first, in how to operate and 4.3.8 Community Based Arsenic Treatment PlantsIn 1998-99, various types of small-scale arsenic removal plants were introduced in pilot projects where severe arsenic contamination of HTWs was detected. In Noakhali one small scale, community - managed tank system with tap enjoyed a high degree of social acceptability. Field reports show that consumers preferred the taste of be filtered water since the aluminum sulphate based purification process removed the iron and other impurities at the same time so improving water quality. This fining presents a vital clue as to the potential for acceptability and cost recovery of similar options. The cost of treatment and the additives in this treatment system (mainly alum) were low and thus affordable. There have since been health concerns, however, arising from the continual ingestion over time of traces of aluminum sulphate. Additionally, the long-term problem arising from any treatment plant remains the safe disposal of contaminated sludge. Much more research will be needed to ascertain how this can best be done, if domestic treatment continues to be advocated. 4.3.9 Ring Wells and Other Local SolutionsRing wells are used in the EH regions where geological conditions make it difficult to drill wells. Special wells such as shrouded tube wells are used in the coastal areas, but are difficult to drill and often fail. They are unlikely to be a sustainable solution as demands increase, though they may be fitted with pumps and concrete seals to make them more attractive to consumers. 4.3.10 Compatibility with NWPo andNPSWSSAll of these options are compatible with the NWPo in that they fulfill primary human needs. However, to be in conformity with the 1998 NPSWSS, a proportion of the cost would need to be met by beneficiary contribution. In areas of arsenic contamination where many consumers have invested in HTWs at the instigation of government health bulletins and media campaigns, the proposal that people abandon their independent water source (paid for at individual expense, in many cases) in favor of shared, surface water sources, supplying water outside the bari is unlikely to be acceptable.4.3.11 Other Environmental ImpactsRisks to flood-proofed piped systems and cost of rehabilitation from flooding, drought and cyclone are less than to individual HTWs though leakage in pipes laid in flood-prone or water logged areas may lead to contamination of the water supply. Pond sand filters may be more vulnerable to contamination if strong bunds are not built up and maintained to protect them from flood impacts. Treatment plants may also produce adverse environmental impacts if contaminated arsenic sludge becomes inunundated by floodwaters. Options for water supply respond to one of the most basic of human needs. In terms of coverage and potential contribution to national need, it is presumed that benefits to health and quality of life will accrue to all recipients of piped water supply in a hydrological region at all service levels (village, Union, Thana and District) and therefore, the coverage and benefits would be greater than in many other options. 4.3.12 Community Based Water Supply Management OptionsThe NPSWSS advocates the future development of water supply and sanitation through local bodies, private-public sector partnerships, NGOs, CBOs and women’s groups (WATSAN committees among others). As part of the trend to devolve planning and management to community 1evel pilot schemes such as the Rajshahi SDC/CARE/WATSAN project have been put in place to test possible models. The UNDP funded Sustainable Environmental Management Plan (which is implementing 26 projects through MOEF) is also supporting the development of other models in WSS and related sectors such as the community-based ‘Rural Water and Sanitation Schemes’ (with DPHE), the urban solid waste management projects in Dhaka (with the NGO, Waste Concern), the urban waste water treatment in Khulna City (with the NGO, PRISM), and the community based rural industrial waste management scheme for small-scale textile dying. These are important since they are entirely demand driven and locally managed, and as such, represent a new private sector paradigm for Bangladesh. Economic incentives will probably need to be provided in the future to attract private investors to provide rural water supply systems, based on these or other models while, at the same time, to set up and institute privately monitored but community-managed systems of cost recovery. 4.3.13 Mass Media and Awareness RaisingThe use of mass media (particularly television) for disseminating public interest messages has been particularly successful in Bangladesh over the last decade. The visual stimulus of television provides an excellent conduit for ideas to be conveyed to the public in a way, which is both informative and engaging. In recognition of the fact that behavioral change will only come about through increased public education, it is proposed to use the medium of television to create awareness of the NWPo, and to give the public access to essential information on new safe water systems, best sanitation and hygiene practice, and environmental conservation and protection. The campaign is to be entitled ‘Water is Life’. The first part will consist of a series of four programs on water and sanitation and the second, two programs on water resource management. The public awareness campaigns will target rural men and women though women as collectors of water and managers of the domestic environment will form the major focus. These programs will be developed in collaboration with the rural communities. To attract interest in the ‘Water is Life’ campaign, the programs should be based on field research and broadcast with the help of rural women, in a range of regional dialects. Location shooting will provide the most authentic environment for these programs and attract the most interest. For the programs aimed at men, rural men, not actors, should also be involved in broadcast and production. The programs should target low to middle - income users and address the range of ethnic and religious minorities across Bangladesh including the Chittagong Hill Tracts. Optimal timing of the broadcasts should be determined by field studies of peak television watching hours of men and women. In areas like the CHT where television access is constrained, radio programs in indigenous languages should also be recorded and broadcast with the same messages. 4.3.14 Review of Rural Water Supply optionsSubsidized water supplies only meet a small proportion of need and in the future, private sector capital will probably need to be sought to provide additional resources. Involvement of the private sector also offers the most potential for stimulating innovations in technology and improving equity of access to all consumers. The following development strategies are worthy of consideration:
|
