NATURAL ARSENIC IN GROUNDWATER: OCCURRENCE, REMEDIATION AND MANAGEMENT - CHAPTER 30 ppsx

Section 5: Management of arsenic-rich groundwaters Copyright © 2005 Taylor & Francis Group plc, London, UK Management of the groundwater arsenic disaster in Bangladesh K.M. Ahmed Department of Geology, University of Dhaka, Dhaka, Bangladesh ABSTRACT: Arsenic contamination of groundwater in Bangladesh has emerged as the largest water pollution event in the world. In Bangladesh it had been thought that more than 97% of the population had access to safe drinking water until recently and because of detection of arsenic in groundwater, the main source of drinking water in rural and urban areas, the access has come down to 80%. The recent increase in rice production is also attributed to groundwater irrigation and about 70% of irrigation water is abstracted from the aquifers, which account for 85% of the total abstracted groundwater. The presence of arsenic in groundwater has become a major issue of man- agement of both drinking and irrigation water in the country. Analysis of about 4 million wells by field kit show that about one third of the wells exceed the BDWS of 50 ␮g/L. If the WHO provi- sional guideline value, 10␮g/L, is considered two thirds of the wells become unsafe. About 30 to 70 million people are exposed to unsafe level of arsenic in their drinking water. Yet another potential intake source remains unknown i.e. the entries through the food chain due to irrigation with arsenic contaminated groundwater. Scientific investigations have demonstrated that arsenic contamination does not occur randomly; rather geology and hydrogeology control it. Groundwater in Bangladesh has never been considered as a precious resource; rather it has been used indiscriminately. For management of arsenic in groundwater, a pragmatic mitigation policy is needed with a holistic approach. Legal and institutional reforms are necessary to address the issue. Concepts of safe drinking water and integrated water resources management should be adopted in order to manage the problem scientifically. Proper assessment has to be performed to avoid substitution of new risks while implementing new sources. Community participation has to be ensured in the man- agement by raising the level of awareness about the quality and quantity of the vital resource. 1 INTRODUCTION Bangladesh relies intensely on groundwater for rural and urban water supply and achieved remarkable success in providing access to safe water to 97% of the population. Increased irriga- tion coverage with groundwater contributing for more than 70% made the country safe reliant in rice production, the staple food the 130 million people. The exponential increase in groundwater exploitation has been prompted by easy availability and low cost technologies. The detection of arsenic above admissible limits in shallow groundwater of Bangladesh has emerged as a severe environmental hazard and the use of groundwater both for drinking and irrigation purposes being questioned. Groundwater management is in poor state despite large dependence on groundwater. The theme of this paper is management of groundwater for safe and sustainable use, mainly for drinking purposes as it warrants the top priority among all uses. 1.1 Arsenic contamination situation Since the first detection of arsenic in 1993, a number of studies have been carried out to determine the extent of the problem. Until recently a large proportion of the country’s 8 to 10 million water supply wells have been tested using field kits. At the same time, water samples from a relatively 283 Natural Arsenic in Groundwater: Occurrence, Remediation and Management – Bundschuh, Bhattacharya and Chandrasekharam (eds) © 2005, Taylor & Francis Group, London, ISBN 04 1536 700 X Copyright © 2005 Taylor & Francis Group plc, London, UK small number of wells have also been analyzed using laboratory techniques. Field kit analysis of about 4 million wells from 402 Upazilas (sub-district) out of about 500 reveal that about 30% of the wells have arsenic above the Bangladesh drinking water standard (BDWS) of 0.05 mg/L (Fig. 1a). On the other hand, laboratory analyses of 44000 wells by various agencies show that 34% wells yield water with more than 0.05 mg/L As (Fig. 1b). Among the tested Upazilas there are extreme variations in the extent of occurrence of wells with As above the BDWS – in some Upazilas almost all tested wells exceed the limit, in some 284 0 10 20 30 40 50 % of Tested Wells < 0.01 0.01-0.05 > 0.05 Arsenic Concentrations (mg/L) 0 20 40 60 80 100 120 BAMWSP 156 UNICEF & Others 54 Full 210 DPHE 192 Total 402 Screened Upazila % Tested Wells <0.05 mg/L >0.05 mg/L <0.05 mg/L >0.05 mg/L% of wells 020406080100 <50 >=50 to < 150 >=150 to < 250 >=250 to <500 >=500 to <750 >=750 to <1000 >=1000 Depth ranges (feet) % of wells Figure 1. (a) Percentage of wells exceeding BDWS under various field kit surveys (summary of about 4 mil- lion tests); (b) Percentage of wells under different concentrations ranges (summary of 44,000 laboratory analyses); (c) BAMWSP data from 66 upazila show that a larger proportion of wells from depth Ͼ500 feet exceed the BDWS (Fig. 1c). Copyright © 2005 Taylor & Francis Group plc, London, UK other Upazilas none exceed the limit. However, there are distinct spatial patterns in occurrence as shown in Figure 2. It is evident from the figure that significantly large proportions of wells located in the southern sub-districts exceed the BDWS compared to the wells located in the north. It has been reported by number of studies that spatial distribution of As occurrences is controlled by sur- face geology, i.e. most wells located in the areas occupied by the fine and young floodplains and deltaic sediments exceed BDWS more frequently, wells installed in Holocene coarse fan deposits rarely exceed the BDWS and wells developed in Pleistocene and older never exceed the BDWS (BGS & DPHE 2001, Ahmed et al. 2004). Also there is depth control in the occurrence of high As in groundwater. The peak concentration occurs at 20–40 m, whereas aquifers above and below have lower concentrations. BGS & DPHE (2001) reports that aquifers deeper than 150 m have consist- ently low arsenic. Other studies report occurrence of low As water at shallower (van Geen et al. 2004) and deeper depths (JICA 2003). However, BAMWSP data from 66 upazila show that a larger pro- portion of wells from depth Ͼ500 feet exceed the BDWS (Fig. 1c). These findings are contradic- tory to earlier studies and needs further investigation. It has been established from different studies 285 Rivers % of wells exceding 0.05 mg/L 0 - 1 1.1 - 20 20.1 - 40 40.1 - 60 60.1 - 80 80.1 - 100 No data 80 800 kilometers Bay of Bengal 26°25°24°23°22°21° 26° 25° 24° 23° 22° 21° 88° 89° 90° 91° 92° 88° 89° 90° 91° 92° Figure 2. Distribution of wells exceeding the BDWS for arsenic in different Upazilas (data from BAMWSP, DPHE/UNICEF). Copyright © 2005 Taylor & Francis Group plc, London, UK that there is no specific depth for the occurrence of As safe water, rather it is controlled by the sub- surface geology and hydrologic conditions (Ahmed 2003a). 1.2 Share of groundwater in water supply and irrigation Groundwater has been the main element for two recent achievements of Bangladesh in the field of access to safe water and food security. Due to extensive use of groundwater, facilitated by easy availability of prolific aquifers, low-tech installation procedure and affordable cost, 97% of the total population came under the safe water supply. The number of domestic water supply wells increased many folds over last 3 decades and 90% of these are privately owned (van Geen et al. 2002). Groundwater is also the main sources of municipal water supplies in urban areas including the capital city Dhaka. In fact Dhaka is one of the mega cities of the world, which rely almost entirely on groundwater for water supply (Ahmed et al. 1999, Morris et al. 2003). The second suc- cess that the country achieved recently is attaining self-sufficiency in rice production. This has been made possible by the role of groundwater-based minor irrigation systems, which now accounts for more than 75% of the total coverage. Though irrigation started in Bangladesh by using surface water, the source has shifted from surface to groundwater as shown in Figure 3. Both the successes have been posed with the recent threat due to As occurrences in groundwater. As nearly 30% of the wells exceed the BDWS, the population previously considered to have access to safe water is now known to be exposed to high As in their drinking water. Also the issue of arsenic transfer through food chain due to irrigation with high As water is becoming a matter of concern as many studies have reported arsenic buildup in soil and crops (Huq & Naidu 2003, Farid et al. 2003). 1.3 Arsenic management issue Occurrences of As above permissible limit have exposed millions of people to mass poisoning (Smith et al. 2000). It is considered that the groundwater As catastrophe has emerged due to poor or no management of drinking water sources in Bangladesh (Ahmed & Ravenscroft 2000). For the last 5–6 years, there have been efforts to mitigate the problem but the pace of mitigation activities does not match the extent and severity of the problem (Chakraborty et al. 2002). Various options have been suggested and tested at various locations (van Geen et al. 2002, van Geen et al. 2003). There are suggestions for a variety of mitigation options and strategies (WHO 2000, Hoque et al. 2000, GOB 2002, Yu et al. 2003, Alaerts & Khouri 2004). At the same time there are uncertainties regarding various options which need further investigations before being applied (Burgess et al. 2002a, b, Cuthbert et al. 2002, Caldwell et al. 2003). Also the role of irrigation in the As mobiliza- tion process is considered important (Harvey et al. 2002) and the food chain issues are becoming 286 75.10 76.32 75.33 74.96 24.90 23.68 24.67 25.04 35.57 37.66 38.5 40.08 2000 2001 2002 2003 Groundwater (%) Surface Water (%) Total Area (Million Hectres) Figure 3. Area covered by surface and groundwater irrigation (data from BADC irrigation census). Copyright © 2005 Taylor & Francis Group plc, London, UK more and more important (Huq & Naidu 2003). Therefore, one needs to consider both the water supply and irrigation issues together while planning for As management in Bangladesh. The current paper attempts to provide a preliminary risk assessment of different groundwater-based As-safe sources based on limited data. At the same time a broader framework for groundwater manage- ment in the country will be provided under the existing guidelines and policies. Also research needs and local capacity building issues will be highlighted for sustainable management of groundwater. 1.4 Hydrogeological setting of Bangladesh Both the spatial and depth distribution of As occurrences in Bangladesh groundwater is controlled by geological and hydrogeological factors. It is therefore important to provide a broad overview of regional hydrogeology and groundwater occurrences. The country can be broadly divided into six major hydrogeological units (Ahmed 2003b). However, if minor details are considered the number of units increases up to 40 (UNDP 1982, MPO 1985). Figure 4 shows the major hydrogeological zones of the country which are: Zone I – Holocene Piedmont Plains, Zone II – Holocene Deltaic- and Flood-plains, Zone III – Pleistocene Terraces, Zone IV – Holocene Depressions, Zone V – Tertiary Hills, and Zone VI – Holocene Coastal Plains. Aquifer conditions and quality of groundwater vary significantly from unit to unit. Table 1 presents the major aquifer systems of the country and it is evident that the thick sedimentary successions in the Bengal Basin form prolific multi-layer aquifer systems. Thickness and lateral continuity of the different aquifers vary signifi- cantly from zone to zone, i.e. the Plio-Pleistocene aquifer occurs at a depth of around 300m in the coastal area, whereas the same aquifer occurs only at 10 to 30m in the Pleistocene Terraces. 2 OPTIONS FOR ARSENIC SAFE WATER Various options are being suggested as sources of arsenic safe water involving use of rainwater, surface water and groundwater (BRAC 2000, Hoque et al. 2000, van Geen et al. 2002, GOB 2002, Yu et al. 2003, van Geen et al. 2003, GOB 2003, BRAC 2003, BRAC & WB 2003). The options can be broadly classified under two groups viz. existing sources and new sources. Different sources are briefly discussed in the following sections. 2.1 Use of existing sources 2.1.1 Well switching It has come out from arsenic test results in various areas of Bangladesh that there is enormous variability in spatial distribution of arsenic from district to village scales. In some areas, like in the districts of Chandpur, Lakshmipur, Comilla, Noakhali, Faridpur, Gopalganj, Shariatpur, Munshiganj, almost all well water exceed the BDWS whereas over most of the country there is an intimate association of safe and adjacent unsafe wells. In such areas one good option is to switch the source of drinking water. It has been reported from one area where 52% wells exceed the BDWS that almost 90% of the inhabitants live within 100 m of a safe well (van Geen et al. 2002). In such settings public awareness and dissemination campaigns can motivate the people to share the good wells with their neighbors. Monitoring becomes a crucial concern in this case, as it has been suggested that arsenic concentrations should be expected to rise in the future, even at wells that are currently safe (Burgess et al. 2002b). 2.2 Introduction of new sources 2.2.1 Surface water sources People in Bangladesh used to drink surface water from rivers, ponds, canals etc. Groundwater was introduced as drinking water in early 70s as thousands of people used to die every year due to 287 Copyright © 2005 Taylor & Francis Group plc, London, UK water born diseases. As the tube well technology became very popular surface water sources have been abandoned. At the same time safe surface water has also become a matter of concern due to indiscriminate disposal of industrial and municipal wastes and overall poor sanitation condition in the country. Under current conditions surface water is not consumable without treatment. As sur- face water has been found mostly safe from arsenic, there are strong campaigns for use of surface water as drinking water. Large-scale surface water treatment plants are operational in a number of cities including Dhaka. Pond sand filters (PSF) are being considered as a source of safe water and are being installed in various parts of the country (GOB 2003, BRAC 2003). 288 Figure 4. (a) Major hydrogeological zones of Bangladesh; and (b) Schematic NS geological cross section across western Bangladesh. Aquifers of the north: (a) Shallow Holocene fan deposits and (b) Deeper Plio- Pleistocene fluvial deposits (both the aquifers are arsenic safe). Aquifers of the south: (1) Upper shallow aquifer composed of Holocene fine to very fine sands (severely arsenic contaminated); (2) Intermediate Holocene medium to coarse sand aquifer with occasional gravels (sparsely arsenic contaminated); (3) Lower shallow Holocene fine to medium sand aquifer (mostly brackish water) and (4) Deep Plio-Pleistocene aquifer (fresh, arsenic safe) (after Ahmed 2003b). Copyright © 2005 Taylor & Francis Group plc, London, UK 2.2.2 Rainwater harvesting Harvesting of rainwater is also considered as a source of arsenic safe water in Bangladesh, at least during the monsoon months as there is abundant rainfall during this time (Ahmed 2003, GOB 2003, BRAC 2003). 2.2.3 Very shallow groundwater Abstraction of groundwater in Bangladesh started with dug wells although they became almost extinct due to the overwhelming increase in the number of tube wells over the last three decades. It has been found in many places that dug well water contains arsenic at very low concentrations even in the severely arsenic affected areas (BGS & DPHE 2001). The use of dug wells as a source of arsenic safe water is being considered and various noble designs have been suggested to make them safe (Ahmed 2003, GOB 2002, GOB 2003). 2.2.4 Deep groundwater Use of deep safe groundwater is considered as one of the main options for As safe water supply (Ahmed 2003, van Geen et al. 2003, Yu et al. 2003). Deeper groundwater is As safe all over the country though the safe depth varies considerably from place to place, even at village scale (BGS & DPHE 2001, JICA 2002, van Geen et al. 2003). Deep groundwater is the most popular safe water option among the community (BRAC 2003; BRAC & WB 2003). It has been reported that one deep well, if installed strategically, can serve a population of 500 within a catchment of 300 m radius (van Geen et al. 2003). Yu et al. (2003) conclude that if the 31% of the existing wells exceeding the BDWS is replaced by deep wells, health effects related to drinking As rich water can be reduced by 70%. 2.3 Relative risks of various sources While introducing any new source of water, the relative risk of the options has to be considered. Moreover, if not careful enough, a new risk might be substituted inadvertently while introducing a new source – risk of As in Bangladesh drinking water is a classical example. While reducing the risk of microbiological contaminants, As risk has been substituted inadvertently (Smith et al. 2000). Due to this now there are strong campaigns by some groups to return to surface water. However, there are suggestions that the shifting from tube wells should be as limited as possible by using the safe wells (Calddwell et al. 2003). The same study also concludes that the most urgent need is not changing source of water but comprehensive national water testing providing essential 289 Table 1. Aquifer systems of Bangladesh. UNDP BGS & DPHE Aggarwal 1982 2001 et al. 2001 JICA 2002 GOB 2002 Arsenic status Composite Upper shallow 1st aquifer Shallow aquifer Upper Holocene Shallowest part aquifer aquifer (1st aquifer) aquifer uncontaminated; lower part contaminated Middle Holocene Most severely aquifer contaminated, peak arsenic concentrations occur here Main Lower shallow 2nd aquifer Middle aquifer Lower Holocene Least aquifer aquifer (2nd aquifer) aquifer contaminated Deep aquifer Deep aquifer 3rd aquifer Deep aquifer Plio-Pleistocene Uncontaminated (3rd aquifer) aquifer Copyright © 2005 Taylor & Francis Group plc, London, UK information to households about the safe and unsafe wells. Moreover, the potential exposure to As sources other than drinking water make risk assessment of arsenic in drinking water difficult (Buchet & Lison 2000). Therefore, one has to be extremely careful in recommending alternative source of drinking water without assessing the relative risks and possible exposure through other sources. All the different sources considered for As safe water has different risks associated. It is not possible at this stage to rank different options in the absence of various quantitative matrixes. Therefore, the qualitative risk factors associated with various options are discussed here. Also find- ings from different studies with various options are considered in assessing the risks (Sutherland et al. 2001, van Geen et al. 2002, van Geen et al. 2003, Burgess et al. 2002a, b, Cutbert et al. 2002, Yu et al. 2003, BRAC 2003, BRAC & WB 2003, GOB 2003) • Well switching may give rise to social problems in sharing individually owned wells; larger abstraction rate may influence the water quality; may not be suitably located for sharing by the neighbors. • Removal efficiencies influenced by raw water chemistry; sludge disposal is a major issue – can create other sources of exposures; household level management more difficult; not liked much by the community. • Surface water sources have high risk of microbiological contamination; pond sand filter may not remove all microorganisms; source protection is a major issue; not equally available in space and time; can have other heavy metals from industrial wastes; reports of occurrences of toxins derived from cyanobacteria; chemical and microbiological quality can vary abruptly in response to flow conditions and land use practices; not considered as the best option by the community. • Rainwater is unequally distributed in time; storage is a major issue; quality deterioration during long-term storage is a matter of concern; long-term consumption can lead to element defi- ciency; not liked by the community. • Dug wells can not be developed under all types of geological and hydrogeological conditions; there are risks of microbiological contamination if not well protected and placed at safe dis- tances from existing sources of pollutions; there are reports of As occurrences above the BDWS; other chemical parameters such as nitrate and manganese can also be limiting factors; can become dry during drought/low water table conditions; not considered as a best option by the community. • Deep tube wells can have arsenic and other chemical contaminants in some areas; can induce leakage of As rich water from upper aquifers if pumping rate is high; poor construction can result into short circuiting of arsenic rich water; arsenic may be released from aquifer sediments under changed hydrogeochemical conditions imposed by new pumping regimes; possibilities of resource depletion if abstraction is not regulated. It is evident from the discussions above that none of the option is risk free. In selecting a particu- lar option one needs to consider the relative microbiological and chemical quality factors along side sustainability, affordability and acceptability by the community. Community options rather than household options should get priority for the ease of management and monitoring. Use of deep or safe community wells seems to be the most practical option available to reduce the arsenic exposure, also this is most liked by the community (van Geen et al. 2003, Yu et al. 2003, BRAC & WB 2003). If piped water systems are introduced in smaller urban centers and rural areas, as out- lined in the arsenic mitigation policy of the government, the same source can be used. 3 MANAGEMENT OF ARSENIC ENRICHED GROUNDWATER The issue of arsenic management is very wide and includes management of water resources, sources of water supplies, provision of alternative sources, health aspects, social aspects, agricul- tural issues etc. Though all these are important and one can not speak of arsenic management without a holistic approach, many of the issues are outside the subject matter of the paper. And, therefore, the issue of arsenic enriched groundwater management is highlighted here. 290 Copyright © 2005 Taylor & Francis Group plc, London, UK 3.1 Arsenic in existing national policies In Bangladesh there are number of modern policies which can be utilized in management of As enrichment of groundwater. The policies adopted prior to detection of arsenic naturally do not address the issue. However, the recently adopted policies address the issue and the most relevant ones are the National Policy for Safe Water Supply & Sanitation 1998 and National Water Policy 1999. These two policies lay the foundation of groundwater management in the country. A new policy focusing only of arsenic, National Arsenic Mitigation Policy 2004, has been adopted recently by the council of ministers. Also National Environmental Policy and National Environment Management Action Plan 1992 can be used to introduce relevant legal instruments for arsenic management. National Policy for Safe Water Supply & Sanitation 1998: The policy sets a goal for the gov- ernment to ensure that all people have access to safe water and sanitation services at affordable cost. In the policy document safe water supply is defined as ‘means of withdrawal or abstraction of either ground or surface water as well as harvesting rainwater water, its subsequent treatment, storage, transmission and distribution for domestic use”. The goals and objectives includes, among various other issues, reduction of incidence of water borne disease, ensuring supply of quality water through observance of accepted quality standards and removal of arsenic from drink- ing water and supply of arsenic free water from alternative sources in arsenic affected areas. The strategy of the policy is set to development goals based on a number of principles including prece- dence on safe water from surface sources. The strategy also emphasizes on regular and coord- inated water quality surveillance to controlling and preventing contamination of drinking water. The policy asks for excavation or re-excavation and preservation of at least one pond in each and every villages of Bangladesh with necessary security measures to prevent water of the pond from contamination. For urban water supplies it also emphasizes on monitoring of water quality for the purpose of ensuring an acceptable standard. National Water Policy 1999: The national water policy is declared “to ensure continued progress towards fulfilling the national goals of economic development, poverty alleviation, food security, public health and safety, decent standard of living for the people and protection of nat- ural environment”. The policy will guide management of water resources of the country by all concerned agencies. The policy states “the ownership of water does not vest in an individual but in the state. The Government reserves the right to allocate water to ensure equitable distribution, efficient development and use, and to address poverty”. Under the water supply and sanitation section the policy identify number of problems related to groundwater, viz. arsenic contamination, heavy withdrawals for irrigation and subsequent decline in water table, seepage of agrochemicals into shallow aquifers, and salinity intrusion. On the other hand, in the water and agriculture section, it encourages future groundwater development for irri- gation subject to regulations prescribed by the government from time to time and without affect- ing drinking water supplies. It also emphasizes strengthening monitoring organizations for tracking groundwater recharge, surface and groundwater use, and changes in surface and ground- water quality. The policy talks about research, central database and enactment of a national water code revising and consolidating the laws governing ownership, development, appropriation, util- ization, conservation, and protection of water resources. 3.2 Institutions involved In Bangladesh there are a large number of organisations involved in water resources development and management. However, currently most of these organisations develop water only, very little management is done. The National Water Policy outlines the institutional arrangements for future integrated water resources management in the country. The Ministry of Water Resources is the focal point in the public sector for water resources management. However, the arsenic issue is cur- rently considered mainly as a water supply issue and therefore, the Ministry of Local Government has been made the focal ministry. The other ministries involved are Ministry of Health and Family Welfare, Ministry of Water Resources, Ministry of Agriculture, and Ministry of Science and Information Technology. There is a high power secretarial committee to co-ordinate the activities 291 Copyright © 2005 Taylor & Francis Group plc, London, UK [...]... in the knowledge gap Overall, there is shortfall of trained personnel for water resources management Training should be given to stakeholders in all levels for efficient management of drinking water sources in particular 3.4.6 Local capacity building Personnel working in relevant government organizations and NGOs need basic hydrogeological training Strengthening of university departments and training... the arsenic problem in Bangladesh: community perspectives Research Monograph Series No 24, BRAC BRAC & WB 2003 Willingness to Pay for Arsenic- Free, Safe Drinking Water in Bangladesh Buchet, J.P & Lison, D 2000 Clues and Uncertainties in the Risk Assessment of Arsenic in Drinking Water Food and Chemical Toxicology 38: S81–S85 Burgess, W.G., Burren, M., Perrin, J & Ahmed, K.M 2002a Constraints on sustainable... Publishing House, Bath EPA, 1999 Understanding the Safe Drinking Water Act EPA 810-F-9 9-0 08 Farid, A.T.M., Roy, K.C., Hossian, K.M & Sen, R 2003 A study of arsenic contaminated irrigation water and its carried over effect on vegetables In M.F Ahmed, M.A Ali, and Z Adeel, (Eds.) Fate of Arsenic in the Environment BUET and UNU, pp 113–121 GOB 2002 Arsenic Mitigation in Bangladesh An outcome of the International... mitigate the current arsenic crisis in Bangladesh Bulletin of the World Health Organization 80: 732–737 WHO 1977 Arsenic in drinking water and resulting arsenic toxicity in India and Bangladesh Recommendations for Action Yu, W.H., Harvey, C.M & Harvey, C.F 2003 Arsenic in groundwater in Bangladesh: A geostatistical and epidemiological framework for evaluating the health effects and potential remedies... drinking water sources BADC has also some monitoring focused more on agricultural uses It is therefore very important to immediately develop a national water quality monitoring and surveillance under DPHE Monitoring systems of BWDB and BADC can feed in additional information to the proposed monitoring 3.4.5 Research and training There are number of gaps in the understanding of the arsenic problem and. .. should be considered while introducing a new source of drinking water and at the same time all existing sources should be checked for all parameters 3.4.2 Reliable testing facilities One major issue in the field of drinking water arsenic occurrence is reliable detection at the desired levels Hundreds of thousands dollars have been spent in testing all existing water sources in the arsenic prone areas by... organizations involved in arsenic enriched groundwater management Sl no Organization Main role Role in arsenic 1 Department of Public Health Providing water supply and Engineering (DPHE) sanitation all over the country except two major cities Testing water sources, finding new sources, providing new sources 2 Bangladesh Arsenic Mitigation Water Supply Project (BAMWSP) Specifically raised to deal with arsenic. .. surveillance and monitoring of water quality and diagnosis and management of patients; impact of arsenic on agriculture will be assessed Although the policy gives priority to all the major issues related to arsenic it could be made more pragmatic The issues which should are important in setting long term goal for arsenic management are discussed in the following sections 3.4 Requirements for sustainable management. .. However, the recently adopted National Arsenic Mitigation Policy will be considered as the main instrument for managing the big problem The main policy statements included in the policy are: • • • access to arsenic- safe water for drinking and cooking will be ensured; all patients will be managed effectively; public awareness will be raised about impact of arsenic contaminated water; 292 Copyright © 2005... controls on the occurrence and distribution of arsenic in Bangladesh groundwater In M.F Ahmed (Ed.) Arsenic Contamination, Bangladesh Perspective, 134–162, ITN, BUET, Dhaka Ahmed, K.M 2003b Constraints and issues of sustainable groundwater exploitation in Bangladesh Proceedings of the International Symposium on Safe and Sustainable Exploitation of Soil & Groundwater Resources in Asia, Okayama University, . Willingness to Pay for Arsenic- Free, Safe Drinking Water in Bangladesh. Buchet, J.P. & Lison, D. 2000. Clues and Uncertainties in the Risk Assessment of Arsenic in Drinking Water. Food and. well-switching to mitigate the current arsenic crisis in Bangladesh. Bulletin of the World Health Organization 80: 732–737. WHO 1977. Arsenic in drinking water and resulting arsenic toxicity in India. Monitoring systems of BWDB and BADC can feed in additional information to the proposed monitoring. 3.4.5 Research and training There are number of gaps in the understanding of the arsenic problem and