VERSION of June 11th 2005

ONE SOLUTION TO THE ARSENIC PROBLEM:A RETURN TO SURFACE (IMPROVED DUG) WELLS

Sakila Afroz Joya, Bivash Chandra Barmon, Ariful Islam, Golam Mostofa, Altab Elahi, Jabed Yousuf , Golam Mahiuddin, Mahmuder Rahman, Quazi Quamruzzaman

Dhaka Community Hospital

Richard WilsonDepartment of Physics

Harvard University

A brief history of Worldwide Arsenic Use

Arsenic has been used since 3000 BC 1. In the United Kingdom, for example, it was used to extract iron from iron ore. It has long been known that arsenic is acutely toxic. Anyone who drinks arsenic in water at 60 parts per million (ppm) will soon die. Miners took particular precautions to avoid exposure. Arsenic was also used for criminal purposes to poison a rival and may, for example, have been used to poison Napoleon in his exile.

However, chemicals and substances are often only dangerous at high doses. Indeed at lower doses beneficial effects can often occur. Arsenic has been used for about 2 centuries for medicinal purposes. At fairly high doses it was successfully used as a cure for syphilis before antibiotics entered the pharmacopoeia 70 years ago. Arsenic in moderately high doses repeated over a month has been shown to assist in curing some leukemia2. In a 1% solution of arsenite3 it was introduced in 1785 by Dr. Fowler, of Edinburgh, (UK) and was an imitation of a popular remedy known as "Tasteless Ague and Fever Drops." It was used as a “mild tonic for digestive disorders”.. That arsenic at low levels is safe seemed to be reinforced by animal studies that seemed to show that arsenic is beneficial (to animals) at low doses. Indeed, the fact that laboratory animals (mice, rats, cats, and dogs) could not be persuaded to develop cancer misled toxicologists throughout the world and greatly contributed to the present catastrophe in Bangldesh. One of the present autors (RW) contributed to this misunderstanding by arguing that the observed carcinogencity of arsenic was probeably due to inhlation exposure.4 Others have written about other possible beneficial effects at very low levels.5

Thus a myth developed that while the acute effects of a large single dose are lethal, the chronic effects of a small repeated dose were either small or beneficial. But we now know that this perception is wrong.

Another myth is pervasive throughout society and across cultures. That the effect of an 1 Partington, J. R., 1935.Origins and Development of Applied Chemistry,Longman, London.

1

ingested or inhaled substance is either adverse or beneficial but not both. We now know that it can be both simultaneously, even at the same dose, with one medical outcome being beneficial and another adverse. For chronic exposures, the adverse effects of arsenic dominate.

A brief history of water use in Bangladesh

Water is life. Water for human consumption should be potable, which should be: - Easily accessible - Adequate in quantity throughout the year - Free from contamination - Clear - Pleasant to taste - Odorless - Arsenic free - Germ free - Toxin free - Acceptable- Affordable - Convenient - User friendly- Sustainable

People of Bangladesh in the past 40 to 50 years, have been abstracting this water fromground water by sinking hand/shallow tube wells and deep tube wells for drinking and domestic water and also for irrigation. The water available in the saturation zone (pores completely filled with water) is known as ground water. Physically ground water is generally clear, colorless with little or no suspended solids. The water is also free from diseases producing microorganisms, which causes high prevalence of diarrheal diseases in Bangladesh. The only disadvantages seemed to be due to high iron content (the iron makes cooked food blackish in color) and hard.

Ground water is available in large quantities in shallow depths. The amount of ground water that can be obtained from an area depends on the characteristics of the underlying aquifer and the extent and frequency of recharge. Betweeen 1980 and 2000, Bangladesh achieved a remarkable success by providing 97% of the rural population with bacteriologically safe tube well water. This success led simultaenously to a disaster. Rural people were made aware of the importance of drinking bacteriologically safe water and rapidly developed their habit of drinking Tube Well water. Unfortunately arsenic in shallow ground water aquifers is at an unacceptable level. Data from the Brtish Geological Survey (BGS) were used to estimate that 30 million people in Bangladesh are living with arsenic at levels greater than 50 g/l 6 but 50 million people in Bangladesh are living with arsenic at levels greater than 10 g/l and are therefore under the threat of arsenic poisoning. However scientists at Dhaka Community Hospital estimate an even

2

higher number - possibly 80 million people are at risk of arsenic poisoning in Bangladesh. Of these a large fraction – between 200,000 and 1,000,000 will develop skin lesions or internal cancers as estimated, for example by Harvey et al.7

Today possibly more than 3 million affected shallow tube wells are used for drinking water. Out of the total 64 districts of Bangladesh, in 50 districts arsenic has been found above 50 µg/l (the recommended level of arsenic in drinking water of Bangladesh) and in 60 districts above 10 µg/l (which is the World Health Organization (WHO) recommended maximum level of arsenic in drinking water).

Soon after the arsenic problem was discuvered, it was widely suggested that a simple option is to drill te wells deeper – to below a clay layer where the water is relatively arsenic free.But in some areas the deep tube wells are found to be already contaminated with arsenic so that this is not a solution. Moreover it is feared that the deep aquifer may become contamitated with use.

In some villages 100% tube wells are contaminated with high level of arsenic. DCH and Dipankar Chakraborti, Jadovpur University, Kolkata, India, jointly surveyed on arsenic affected areas of Bangladesh and prepared the following maps (Fig. 1&2). Similar maps have been prepared by others such as the British Geological Survey8. A listing of tube wells and their measurement is available at NAMIC.9

Figure-1 Figure-2

Moreover in Bangladesh the water demand is increasing rapidly. 82% of the water supply system depends (in 2005) on ground water of which 95%goes for irrigation and only 5% used for drinking and cooking. In Dhaka continuous extraction of ground water is non rechargeable at

3

the same rate of extraction, and has resulted in severe lowering of the ground water level. According to the WASA report 2003 10, the ground water level that was 11m in 1970s went down to 20m in 1980s. It is estimated that it will go below 45m by 2016. Which, it is predicted, will create a severe crisis to meet future water demand. If reliance is placed on deep tube wells the same may happen elsewhere. So we have to reduce the load on ground water use and have to make alternative water supply options based on arsenic free surface water that is abundant in Bangladesh and was historically the source of water. Surface water is abundant in the wet season in Bangladesh. An estimated 795,000 million cubic meter of surface water is discharged per year through the Gangaes and Brahmaputra. This is equivalent to 5.52 m deep water over the land area of 144,000km2.

The Government of Bangladesh (GOB) in its national policy on arsenic mitigation11 gave priority to surface water use among other options. Most of the people used dug wells along with other surface water sources before 1985 when tube wells were suggested and encouraged. The only problems of these surface water options are contamination with high level of bacteria along with few other contaminants (such as iron, and phosphate).

These can be overcome easily if the surface water can be treated and maintained properly. Due to poor management and improper investment, we are hardly utilizing the abundant surface water with which Bangladesh is blessed. Now time has come to protect our next generation from drinking arsenic poisoned ground water by proper management of surface water, which is an easily available and affordable water source for the people of our country, and it is also easy to keep safe. In the past years DCH has established 224 Dug Wells, 9 Pond Sand Filters, 5 River Sand Filters and 1,122 systems for Rainwater harvesting. The original 66 dugweels described in this paper have always been free oof bacteiaa, but about 18 dugwells dug later in the Sirajdikhan upazila had contamination after an unusually severe flood and had to be retreated by DCH and now all of them are safe and working. Pond Sand Filters (PSF), River Sand Filters (RSF), and the Rainwater Harvesting systems that are models of safe water provided by DCH are also working satisfactorily.

The worldwide mistake

Starting about 1980 it was suggested that Bengalis, both in Bangladesh and West Bengal, should switch from the use of the abundant, but unsanitary, surface waters, to the use of ground water using simple tube wells. This seemed to have the advantage of vastly improved sanitation, and hopefully a reduction in the incidence of cholera. This was particularly urged by a wide spectrum of western agencies: the World Bank, UNICEF and The British (UK) Geological Survey in particular. In retrospect it is curious that none of these agencies, and none of the “bystanders” insisted, or even seem to have suggested, that the ground water be tested for arsenic and other heavy metals. With 2,000,000 tube wells sunk by, or on behalf of, these agencies and another 8,000,000 sunk privately it is surprising that not even a small sample of these wells were so tested. Even if a sample of 100 wells had been tested in 1980, the agencies would have been alerted.

4

Early warning signs of chronic adverse effects

As early as 1888 Hutchinson12 13 published data showing adverse effects on the human skin from prolonged use of Fowler’s solution. Lung cancers were attributed to inhalation of arsenic pesticides as early as 1897. Neubauer14, among others, had described arsenical cancers in 1947 Skin pigmentation, keratoses and skin cancers were found by Tseng15 16 in Taiwan among people who drank from arsenic contaminated wells (but no effect was seen below about 150 parts per billion (ppb), which might therefore be a biological threshold). Dr KC Saha in Kolkata (India) reported in 198017 that there were cases of arsenic poisoning in West Bengal. But these early warnings were ignored.

The world was finally alerted to unusual risks by the report of a very high incidence of lung, bladder and other cancers in Taiwan by Dr Chien-Jen Chen and colleagues18. It appears that there were, and are, no data on humans to contest the idea that prolonged exposure to low doses is dangerous. But even then it took 10 years for everyone to respond. It is now realized that the catastrophe is much worse than the well known catastrophes of the Chernobyl nuclear power plant accident, the Bhopal isothiocyanate leak or the Kuwait oil fires. Yet for 30% of the Bangladeshi communities, pure water is still a long time away.

Dhaka Community Hospital

Dhaka Community Hospital was founded in 1988 and have 40 clinics dispersed throughout the countryside. DCH became involved with the arsenic problem in 1996 when DCH doctors working at an annual health camp at Pakshi, Pabna District first detected patients suffering symptoms of arsenicosis. DCH lobbied extensively to establish this issue as a public health problem and went on to work with Jadovpur University, Kolkata, India, to survey by sample the whole of Bangladesh. Since then DCH has collaborated with various partners in research into the problem and solutions for mitigation as well as conducting its own arsenic projects.

The choice between solutions

At the first International Conference held by Dhaka Community Hospital in January 1998 held jointly with Jadovpur University, Kolkata, several solutions to the problems were discussed. Either arsenic must be taken out of the water or an alternate solution must be found. There seemed to be some important criteria that any solution must satisfy:

(1) A short term solution might be acceptable if it was implemented on a wide scale at once.(2) A long term solution should fit into a national water policy(3) There was no reason for delay; short term solutions should be implemented at once. If there was delay, the short term quickly became a long term.(4) A simple return to unsanitary surface waters is undesirable

The proposal that was made at once was to have a national survey of wells, and install 5

temporary arsenic removal devices. However 7 years later, there are many villages still without pure water. The arsenic removal devices proved too hard for many villagers to use and many of them were unsatisfactory and were abandoned19. Accordingly DCH has since 2000 been emphasizing longer-term solutions.

Two facets of an overall elimination of the Bangladesh arsenic problem seem to be agreed.

(a) There is no one solution for all places and communities. In some cases purifying the water may be preferred; in others use of arsenic free water is easier.(b) It is vital to involve the local community in the choice involved in the decision and even more important in the follow up and maintenance. (c) The solution in any community and location must be based upon the best possible scientific understanding. (d) Both anecdotal evidence and a detailed survey suggest that villagers are very interested in running water in our near their houses and according to a recent survey seem to be more willing to pay for it than running water than for arsenic free water. This makes it preferable to use a solution which provides running water at the same time as pure water.

The solutions which meet these criteria seem to be:1) Drilling deep wells (150+ m) to a deep aquifer, below a clay layer. Many hydrogeologists suggest that this aquifer is replenished by water from the mountains rather than annually from rainfall. The arsenic contamination of this deep layer is at present much smaller than the arsenic contamination of the ordinary tube wells at a depth of 40 meters. Although it is unclear whether it will always remain so. 20

2) Encouraging a return to surface (dug) wells (DW), but with a strict adherence to WHO sanitary standards. 3) Use of sand filters to filter pond water (PSF) or river water (RSF)4) Storage of rain water

DCH chose the second of these, the use of dug wells, for this demonstration facility in the Pabna district. This report describes three phases of the work, and some indication of further development. Other groups are actively studying other solutions and we make no premature claim on which is superior.

The DCH Dug well Demonstration (Pilot) Project

The project was made possible by charitable donations from a number of foreign individuals and from the OPEC fund supplemented by locally generated funds. Although the project has begun somewhat earlier, it started in full measure in April 2002. In the first phase 39 wells were dug, (or in some cases reconditioned) by February 2003. These wells supplied 631 families and serving 3,250 users. Careful measurement was made of the bacterial content of each well. These wells were of different shapes and sizes, but all had in common the general sanitation features. They were sited remote from latrines. They were covered to prevent the

6

entry of foreign matter, (animals, feces etc) and a small tube well and hand pump on the side extracts the water. During construction the well was properly sealed, the well was carried above a possible flood level, and a conrete apron was put just below the top to reduce ingress of water. The fundamental aim is to prevent ingress of water into the well, except the water that has been filtered through 30 feet of the surrounding soil. Chemicals (lime) were used in the initial installation and subsequent maintenance. In general WHO requirements were followed.21 (See Appendix 1 for the detailed requirements recommended by DCH)

Bringing running Water to Houses

DCH noted that the Bangladesh government electrification program had already brought electricity to 50% of all villages and has the aim of bring electricity to them all by 2020. This makes it easy to install an electric pump to raise the water to a storage tank, from which it is gravity fed to a number (6 or more) individual houses. This has proved very popular and is a major step toward the acceptability of this solution. It is interesting that another grouphas found by survey that the availability of running water is more important in public perception than the fact that the water is arsenic free. Already in phase 1 one well was installed with a storage tank. In phase 2 seventeen new wells were dug and all had the pipeline system installed. Another 518 families were supplied and 2,903 users were served. In phase 3, nine old wells were renovated (brought up to WHO sanitary standards) and one new one dug; all with electric pump, storage tank and pipeline. This supplied another 400 families with 2,400 users. We believe that the positive experience with a pipeline system is a most important part of the demonstarion, pilot, project and we suggest that it will be an important part any solution to the arsenic problem since a pipeline system can be added, for exaple, to a centrally located deep tube well. Another grouop, the Bangladesh Arsenic Mitigation Water Supply Project (BAMWSP) has stated its intention of providing 30 pipeline systems22 .

In all 66 sanitary dug wells have been installed in this demonstration pilot project. The capital cost was about $70,000. This cost is falling with time as we learn how to use indigenous materials and labor. Detail of the cost breakdown is shown in Appendix 3. In figures 3,4 and 5 are shown respectively a typical dug well with attached tube well, the water tank from which gravity feeds the houses, and the tap with pure water in a lady’s kitchen for the first time in history.

7

Figure 3 Figure 4 Figure 5

Procedure for the installation of Dug Well with Pipeline

March and April, which are the driest months in the country, are the best times for digging a well. During this period, ground water remains at the lowest level so that if the well hits water at that time it will always hit water. A hole is dug with a diameter of about 36 inches. The depth of the well varies from place to place. A ring of cement or baked clay is set from bottom to top and the rings are joined by cement to keep the well water safe from contamination from contaminated surface water. An apron of about four feet is made around the head wall and a 30-40 feet drain is constructed at the ground level to avoid water seeping into the well around the head wall. An electric pump pumps water from dug well to an overhead reservoir of 3,000 liters. This overhead tank is installed on an iron stand, 15 feet tall. The stand is fixed on the ground with RCC work. A main water supply pipe (made of 3 /4'' plastic) is connected with the tank for distribution of water to the household level. A GI pipeline of ½ inch plastic is connected with the main line to supply water to each individual household. 40-50 households are connected with a single main supply line.

Detail of Project Implementation

In the implementation of the Dug Well project, DCH found that there were several major distinct activities, none of which can be omitted if success is to be assured: Community mobilization, Committee formation, Training of community workers and the caretaker, Site selection, Drawing of water supply network, Installation of dug well and pipe network, Community meeting, Water quality monitoring.

These are detailed below.

Community mobilizationVarious mobilization and motivational activities were conducted, such as courtyard

meetings, to increase public awareness. Several meetings with the community were held in each

8

village. Local Government of Bangladesh (GoB) elected persons and influential local people were present in meetings along with the DCH personnel. Community people including women, the poor and arsenic patients shared their situation, needs, opinions and preferences about mitigation options with DCH and others.

Committee formation

In each village a committee was formed for the supervision of each stage in the implementation. Each committee was responsible to maintain the option provided to them. DCH and the committees worked together to plan option installation and maintenance. The committee accepted responsibility to collect the community contribution. The committee decided the charges for water use for each family. A caretaker collected money from water users (usually 20 Tk or 35 cents a month for each family). Each family was provided with a water card for payment. Training

Local mistris were selected for construction and maintenance of the options. They were trained on construction work options by DCH trainers. DCH trainers also trained caretakers and users of options.

Site selectionSites for wells were selected in highly contaminated areas. This was done after

consultation with the community. Preference was given to sitting the wells near the patient families and the poor. Sites satisfied guidelines provided for site selection, including but not limited to:- Preparing a Dug Well 30-40 ft away from the latrine and dumping ground of waste materials- Animals are penned away from the Dug Well- The Dug well is installed at a safe distance from cropland and industrial area etc.

Installation of dug well and pipe network,

1) The Dug well is dug manually2) Concrete rings are inserted after completion of digging3) To prevent sand boiling rings are jointed together using cement mortar inside and outside

of rings4) Joint-less flexible PVC floating pipe is connected with the Tube Well . Iron rings,

connected with concrete rings, are used to hold this flexible pipe5) To prevent accidents, during construction of Dug Well, due to collapsing of side-soil and

occasionally asphyxiation from carbon dioxide and methane gases- rope, ladder, a Bosun’s chair and other safety equipment are kept at the site

6) A 30-40 feet drain is constructed at the ground level to avoid water seeping into the well around the head wall.

7) An electric pump pumps water from dug well to an overhead reservoir, installed on an 15 9

feet tall iron stand, of 3,000 liters. 8) A main water supply pipe (made of 3/4'' plastic) is connected with the tank for

distribution of water to the household level. 9) A GI pipeline of ½ inch plastic is connected with the main line to supply water to each

individual household. 40-50 households are connected with a single main supply line.

Community meeting,

Various mobilization and motivational activities such as campaign, courtyard meeting etc were conducted in arsenic affected villages that increased public awareness. Meetings with the community were held in the target villages with the community. Local GoB elected person and influential local people were present in meetings along with DCH personnel. Community people including women, the poor and arsenic patients exchanged opinions and preferences about mitigation options and identified their needs. Priority communities were selected from these meetings. A beneficiary committee was formed for the supervision of each implementation. Each committee was responsible to operate and maintain the option provided to them. DCH and the committees worked together to plan option installation and maintenance. Committee also decided the down payment and monthly charge for water use for each family. Money receipt was provided to the user families after getting the down payment money. The head of the maintenance committee signed a contract paper before installation began. This consent paper covers detailing of the community contribution for the option selected. Water quality monitoring

One of the most important functions of the village committee is the continuous monitoring and guarantee of water quality according to quality guideline prepared by DCH in consultation with experts and according to the WHO guide lines. In this they can call upon the advice and help of Dhaka Community Hospital and others. This aspect of the implementation is so important, and so often neglected that we emphasize it in a separate section here.

The Importance of Measurements

Failure to make adequate measurements has been at the heart of the tragedy of Bangladesh. For 20 years no one measuremed the arsenic levels in even a small sample of the millions of tube wells until it was too late. More recently many small-scale arsenic removal devices were installed without adequate measurements to demonstrate their efficacy. Some NGOs returned to surface waters without following WHO sanitary guidelines and without measurement of possible bacteriological contamination. For this, and other, reasons DCH have insisted on measurements from the outset. Because of the past failures in this regard, DCH recommend that a copy of all measurements be publicly available, for it is important that not only the individual who has the well be convinced, but also DCH and through DCH the wider community. The measurements of this pilot project are available as an appendix to this paper which is also on the web.

10

Measurement of Arsenic Concentrations:

The problem with the requirements for arsenic measurement is that we are asking to reliably measure levels of arsenic at 50 parts per billion in water when other chemicals are present at much higher levels. Laboratory instruments can, in principle, achieve this with no difficulty by gas chromatography (with $30,000 cost for each equipment) but this involves taking samples in the field and bringing them back for measurement. A simple calculation performed 4 years ago showed that there was barely enough equipment in Bangladesh to measure every well every 1000 years! Worse still, an interlaboratory comparison by the International Atomic Energy Agency showed, in an unpublished draft report23, frightening disagreements. Measurements in the field are even worse. The field kits depend upon a visual identification of the color. This depends critically upon the training of the personnel. A group of Bangladeshi and Bengali scientists report on their comparisons in 2002 and insist that “facts and figures demand improved environmentally friendly laboratory techniques to produce reliable data”24 . There is hope on the horizon. More recent (2005) laboratory comparions of water samples with the IAEA laboratory show that several laboratories are in full agreement Some laboratories seem to fail in the precision of the measurements. The lower precision (25%) is not important for the present purpose. Columbia University scientists claim that the Hach kit can be reliable if used in a slightly different manner than recommended by the manufacturer25. Also CLEAN INDIA of New Delhi is developing a cheap, efficient kit that shows great promise.

The measurement of Coliform Bacteria:

The measurement of coliform bacteria is, in principle, much simpler than the measurement of arsenic concentrations although again the reliability in practice is critically important and the frequency of measurements needed for the dug wells is greater than the needed frequency of arsenic measurements. There is general agreement that measurement of coliform bacteria can be reliable. For the first measurements Dhaka Community Hospital had no equipment of their own. Measurements by other institutions were expensive and unreliable and are not reported here. However we aquired a “Delagua” kit26 designed at the University of

23

? PK Aggarwal, M Dargie, M Groening, KM Kulkarni,and JJ Gibson An Inter-Laboratory Comparison of Arsenic analysis in BangladeshIAEA draft reporthttp://phys4.harvard.edu/~wilson/arsenic/measurement/arsenic_inter_laboratory_comparison.pdf24

? Rahman M., Mukherjee D., Sengupta M., Chowdhury U., Lodh D., Chanda C., Roy S., MD. Selim, Quamruzzaman Q., Milton A., Shahidullah S., MD. Rahman T., Chakraborti D. (2002)Effectiveness and Reliability of Arsenic Field Testing Kits: Are the Million Dollar Screening Projects Effective or Not?Journal of Environmental Science and Technology (submitted).25

? Cheng Z., Van Geen, A, Chuangyong, J., Meng, X., Siddique A., Ahmed K.M. and Ahmed K.M. Performance of a household-Level Arsenic removal System during 4 months Deployment in Bangladesh,. Environ. Sci. Tech. 38:3442-3448 (2004)http://phys4.harvard.edu/~wilson/arsenic/measurement/ES_and_T.pdf

11

Surrey and used it for all measurements for the 66 wells reported here. More recently the coliform vial from a JAL-TARA27 measurement kit from CLEAN INDIA in New Delhi to give an initial qualitative test to determine whether a full measurement is necessary. The initial measurements of the 66 dug wells in this project are shown in Appendix 5. . It can be seen that the coliform bacteria levels were low. If water were impure Fecal Coliform (FC) and Total Coliform levels (TC) would be in the thousands Our confidence that this also applies for the first year, when measurements were inadequate, comes from the failure to find, after diligent search, and case of water borne disease: cholera, jaundice or diarhhea. Measurements have been repeated every 3 months and full details are in the web version of this paper.

Further extensions of this project:

This pilot project has can be, and is being, extended considerably in the Pabna region where there has been word of mouth communication creating demand by people from other villages. The installation has been supervized by DCH personnel, but there is a steady increase in the understanding of the villgers themselves. With the financial assistance of UNICEF, DCH have supervised the installation of 137 wells (but only 3 with pipelines) in the Sirajdikhan upazila. In principle, sanitary dug wells could be installed in many other parts of Bangladesh. DCH has at the time of writing supervised 224 Dug Wells, bringing pure water to perhaps 50,000 people – but only 0.1% of the people in Bangladesh who are in need. In all of these the same careful procedures are adopted. In all of them measurements show a zero or very low coliform bacteria count. In some of them, the measurement of the bacteria count and contamination by other metals has been verified by measurements by the International Center for Diarrheal Disease (ICDDRB). As the Dug Well option is further implemented it is important to use indigenous materials and measurement techniques whenever possible. This concept was used in this “pilot” project. A part of the pilot project was clearly to demonstrate all aspects of a remediation method - including a measurement of its cost effectiveness. However, the resources of DCH are limited, so that for widespread use of dug wells it will be necessary for other groups to come forward, learn the details of the simple technology, and to work with, and supervize the villages in the same way. Hopefully some group will take this next step during the coming year.

In addition to the dug wells, Dhaka Community Hospital has started to provide other surface and sub-surface water-based alternative safe water options (River Sand Filters (RSF), Pond Sand Filters (PSF), and Rainwater Harvesting (RWH) in the arsenic affected communities in collaboration with GoB and donor agencies. These pilot, demonstration, projects will also be available for others to follow. DCH also provides training on arsenicosis and arsenic problems through its Institute of Family Health, including training for oversees medical personnel e.g. the Nepalese Health Department. These will be described in forthcoming papers.

Conclusion

The use of a sanitary (dug) well has been shown to be a satisfactory solution for the provision of bacteria free, arsenic free, and running water in several Bangladesh villages. The capital cost is about $5 to $6 per person. Crucial steps in achieving arsenic free and bacteria free water seem to

12

be:Selecting a site suitable for a dug well (one in peat is sure to smell!)Strict adherence to sanitary standards as discussed for example by WHOEnsuring community participation and ownership of each well

Acknowledgments

It is a pleasure to acknowledge the help of the many others who made this work possible. First and foremost, the OPEC fund for International Development and other donors who made the project possible. CLEAN INDIA of New Delhi, started by Dr Ashok Khosla, has been helpful in providing at low cost reliable test equipment. In addition Richard Wilson thanks all the staff of Dhaka Community Hospital for their hospitality.

13

APPENDIX 1 DETAILED GUIDELINES FOR THE CONSTRUCTION OF A DUG WELL

A. Dug Well (DW) Survey

1) A survey and collection of records (number, location, present situation) of any existing Dug Wells in the area should be made

2) The reason that a Dug Well is unused should be determined. Attempts should be made to renovate an existing Dug Well if possible

3) In case of non-availability of any such records, a test borehole should be made to make a bore log at the site.

B. Site Selection

The following factors must be considered in selection of the site: –

1) Areas of peaty soil should be avoided for the Dug Well as these cause the water to have an unpleasant taste and smell.

2) There should be a stable soil layer at the top (a clay layer is preferable)3) Presence of sandy layer within 9 to 12 m (30-40') from ground level is desirable4) The site must be at least 30' away from any existing latrine5) The site must be at least 30' away from pond6) The site must be at least 30' away from a river

C. Dug Well Configuration

1) Inner diameter is 88.2 cm (3') and outer is 1.17 m (4')2) Depth of Dug Well varies with the soil condition and water availability of the site. Depth

should be such to ensure 1 to 1.5 m (3' - 6') water column at the driest period3) Height of concrete ring is 29.4 cm (1')4) Height of head wall is 1 m (3.5') above ground level5) About 59 cm (2') apron is provided all around the well 6) 1.17 m (4') x 75 cm (2.5') platform is provided for Tube Well installation beside apron7) Length of drain pipe attached with the Tube Well platform varies from 1.5 m to 3 m (5' -

10')8) Dug well should be covered to protect it from outside contamination ensuring proper

ventilation and sunlight. The cover is made following WHO guidelines. Or a 0.4m (1’4”) wire mesh should be placed on the head wall, for ventilation and a roof on the top with translucent sheet to facilitate illumination and sunlight.

14

D. Manpower

1) Trained workers (mistris) must be used for construction2) 6 workers (mistris) should be employed for construction work- 1 head mistri, 2 assistant

mistris and 3 local persons to help the mistris so that they become trained after construction of a few Dug Wells.

E. Construction

1) The Dug well should be dug manually2) The Dug well should not be constructed to a pre-specified depth. The required depth

will depend on the soil and water table conditions. Instead it is better to construct the dug well in the dry season, with the objective of achieving about two meters of water in the Dug Well upon completion. This procedure will ensure a sufficient depth of water to remain serviceable year-round.

3) Concrete rings are inserted after completion of digging4) Where the sub-soil formation is not stable enough, the method of caisson driving (widely

used in bridge construction), may be used5) Where the self-sinking method is used, the first ring of the Dug Well should be robustly

fabricated with a cutting edge 6) To prevent sand boiling rings should be jointed together using cement mortar inside and

outside of rings and joint-less flexible PVC, floating pipe can be connected with the Tube Well. Iron rings, connected with concrete rings, can be used to hold this flexible pipe

7) To prevent accidents, during construction of the Dug Well, due to collapsing of side-soil and occasionally asphyxiation from carbon dioxide and methane gases - rope, ladder, Bosun’s chair etc should be kept at the site. No one should be allowed to work alone.

F. Water Quality

1) 30 cm (1') layer of brick chips are placed at the bottom of the well. 1.8 cm or 3/4'' chips are placed at the bottom in 10 cm (4'') layer, 1.3 cm (1/2'') chips are placed in next 10 cm (4'') and 2.5 cm (1'') chips are placed in the last 10 cm (4'').

2) Water parameters should be tested in the laboratory at least two times a year. These parameters should be: pH, color, turbidity, iron, manganese, chloride, total dissolved solids, total coliform (TC), fecal coliform (FC) and arsenic.

3) Well water is cleaned two times a year. For this 2 kg lime is thoroughly mixed with 35 L of water and then it is poured in the well. The well water is stirred and then kept unused for 3 to 4 days. After 3 days the well is unloaded. The well is then filled with fresh water seeping from the aquifer.

15

G. Maintenance.

The village must form a committee to be responsible for regular maintenance. Workers must be trained for this task. If maintenance is not regularly continued it is possible, even likely, that the coliform count will rise and the water become unsanitary. If all requirements are met, we have found that water is of good quality. However the requirement of testing [(3)] should not be omitted.

APPENDIX-2 A typical water supply network

as drawn and posted to supervise implementation

Figure 6

Electric pump

16

Electric pump

Overhead water tank

APPENDIX 3

Typical costs of different types of Dug Wellsexcluding DCH supervision

1 2 3 4 5 6 7 8 9Sl Type of Dug Wells Tap

Points Families Covered

Popul.Covered

Total Cost Per person Cost In:

Average Approx Approx. In Taka USD$

TakaCl.6/Cl5

USDCl.7/Cl.5

1 Improved New Dug Well+ Pipeline Network+ Water Tank(Steel) + Water Tower (Steel Column)

8 50 250 83,260.00 1388 333.00 5.5

2 Improved New Dug Well+ Pipeline Network+ Water Tank(Steel) + Water Tower (Brick Column)

8 50 250 92,760.00 1544 371.00 6.2

3 Improved New Dug Well+ Pipeline Network+ Water Tank(Steel) + Water Tower (RCC Column)

8 50 250 98,610.00 1643 394.44 6.5

4 Improved New Dug Well +Hand Tube Well 1 15 75 58754.00 979 783.00 13.05 Recondition Dug Well + Pipeline Network + Water

tank (Steel) + Water Tower (Steel Column)8 50 250 50,350.00 839 201.00 3.3

6 Recondition Dug Well + Pipeline Network + Water tank (Steel) + Water Tower (Brick Column)

8 50 250 72,070.00 1201 288.00 4.8

7 Recondition Dug Well + Pipeline Network + Water tank (Steel) + Water Tower (RCC Column)

8 50 250 70,220.00 1170 280.00 4.6

8 Recondition Dug Well + Hand Tube Well 1 15 75 31,394.00 523 418.50 7.0 Note:- 1. Calculated at the rate of 1USD = Tk. 60.00

The annual expense for maintaining a dug well is modest and should be borne by the village community. The best time for cleaning is the period between March and April. 2 kg of lime is thoroughly mixed with 35 l of water and then it is poured into the well. The well water is stirred and then kept unused for 3 to 4 days before use. (See Appendix 1) A typical cost breakdown is shown in the table below:

17

Table 4Mainenance Cost

Material Quantity Price Total Tk

Labor charge for cleaning 3 person 400 2000/=

Potash 100 gm 30/=

Lime 3 kg 10 30/=

Repairing and fixing broken, leaking and other damaged parts

1000/=

Total: 3060/= ($53.00) [Calculated at the rate of 1 $ = 58 Thaka ]

Annual Cost 60 Taka per family or 12.Taka per person = 20 cents per person

Typically families pay 10 –20 Taka per month (120-240 Taka per year) This usually includes a small stipend for the caretaker as chosen by the village Option Management Committee (OPC)and the electricity bill for the pump.

18

Cost of Measurements (per well)

At the present time the cost of the measurements is borne by DCH.

Cost of full 15 parameter (including Arsenic) test 5500/= Tk ($95) Performed Initially and when needed

Cost of Preliminary Clean India Test (Jal-Tara kit) $1Performed quarterly

Cost of coliform (FC) measurement is 400/= Tk. ($7) when indicated by Jal-Tara or other test (approximately annually) .

19

APPENDIX Table 5

Dhaka Community Hospital – Pilot Sanitary Dug Well Project - Pabna RegionDepartment of Environmental Research Laboratory Report

Data : Analysis of Arsenic & Bacteriological test in water samplesMethod of Analysis (Arsenic) : Silver Diethyldithiocarbamate MethodMethod of Analysis (Bacteriolocical) : Oxfam-Delagua Kit Method FC = Fecal Coliform per 100ml; TC = Total Coliform per

100mlDW Name Address Date of Fam

iliesPh As

conc.Cond. TDS Turb

.FC TC Date

Code of Install or Covered (ppm) (us) (ppm) (NTU) ofCaretaker Renovate WHO Guide Line Values 1996 First

Village Union Thana 6.5-8.5 0.01 850 1000 5 0 0 TestingDWH -1 Md. Anowar Master Maddhapara UBM - 01 TBC - 01 1999 Nov 12 7.0 <0.03 234 152 <5 0 1 20.06.01

DWH -2 Ramjan Ali Pramanik Ruppur UBR - 02 TBC - 01 1999 Dec 11 7.5 <0.03 212 138 <5 0 0 20.06.01DWH -3 Md. Akbar Hossain Ruppur UBR - 02 TBC - 01 1999 Nov 10 7.1 <0.03 241 157 <5 0 0 20.06.01DWH -4 Md. Tipu Sultan Kazipara UBM - 01 TBC - 01 1999 Dec 12 7.5 <0.03 265 172 <5 0 0 20.06.01DWH -5 Govt. Idara Bissanathpur UBJ - 03 TBC - 01 1999 Nov 15 7.2 <0.03 354 230 <5 0 2 20.06.01DWH -6 Md. Masum Master Sinduri UBJ - 03 TBC - 01 1999 Dec 14 7.0 <0.03 310 168 <5 0 1 20.06.01DWH -7 Md. Nasir Khan Sinduri UBJ - 03 TBC - 01 1999 Nov 13 7.1 <0.03 241 157 <5 0 0 20.06.01DWH -8 Md. Mirja Abdul Halim Aminpur UBJ - 03 TBC - 01 1999 Nov 10 7.2 <0.03 246 160 <5 0 0 20.06.01DWH -9 Md Jamal Hossain Aminpur UBJ - 03 TBC - 01 1999 Nov 15 7.0 <0.03 260 152 <5 0 1 20.06.01DWH -10 Md. Majnu Mia Aminpur UBJ - 03 TBC - 01 1999 Nov 12 7.1 <0.03 212 138 <5 0 1 20.06.01DWH -11 Md. Hanif Sheikh Kalikapur UBJ - 03 TBC - 01 1999 Nov 15 7.0 <0.03 350 228 <5 0 2 20.06.01DWH -12 Md. Ali Hossain Kalikapur UBJ - 03 TBC - 01 1999 Nov 14 7.0 <0.03 235 153 <5 0 1 20.06.01DWH -13 Md. Kader Mondal Kalikapur UBJ - 03 TBC - 01 1999 Nov 10 7.0 <0.03 215 140 <5 0 0 20.06.01DWH -14 Md. Samsur Hossain Nayabari UBJ - 03 TBC - 01 1999 Nov 14 7.2 <0.03 198 129 <5 0 1 20.06.01DWH -15 Md. Jabber Master Nayabari UBJ - 03 TBC - 01 1999 Dec 12 7.1 <0.03 263 171 <5 0 0 20.06.01DWH -16 Md. Abdur Rahman Tangbari UBJ - 03 TBC - 01 1999 Dec 10 7.4 <0.03 325 211 <5 0 3 20.06.01DWH -17 Md. Sohorab (Police) Tangbari UBJ - 03 TBC - 01 1999 Dec 13 7.0 <0.03 349 227 <5 0 0 20.06.01DWH -18 Md. Jahur Ali Tangbari UBJ - 03 TBC - 01 1999 Nov 13 6.9 <0.03 285 185 <5 0 3 20.06.01DWH -19 Md. Lutfor Rahman Tangbari UBJ - 03 TBC - 01 1999 Nov 15 7.0 <0.03 168 109 <5 0 0 20.06.01DWH -20 Md. Mojhar Sheikh Kabaskanda UBJ - 03 TBC - 01 1999 Dec 10 7.0 <0.03 365 237 <5 0 0 20.06.01DWH -21 Md. Sohorab Ali Kabaskanda UBJ - 03 TBC - 01 1999 Dec 15 7.0 <0.03 265 172 <5 0 0 20.06.01DWH -22 Md. Jalil Sheikh Kabaskanda UBJ - 03 TBC - 01 1999 Nov 10 6.9 <0.03 282 183 <5 0 1 20.06.01DWH -23 Md. Juran Mondol Kabaskanda UBJ - 03 TBC - 01 1999 Dec 13 6.8 <0.03 320 208 <5 0 2 20.06.01DWH -24 Md. Monnaf Sinduri UBJ - 03 TBC - 01 1999 Nov 12 7.0 <0.03 315 205 <5 0 0 20.06.01DWH -25 Md. Abdur Rajjak

MasterNatiabari UBJ - 03 TBC - 01 1999 Dec 15 7.0 <0.03 252 164 <5 0 0 20.06.01

DWH -26 Md. Sahadot Hossain Natiabari UBJ - 03 TBC - 01 1999 Nov 10 7.0 <0.03 346 225 <5 0 0 20.06.01DWH -27 Md. Rohmot Ali Rajnarayonp

urUBJ - 03 TBC - 01 1999 Nov 10 7.2 <0.03 292 190 <5 0 2 20.06.01

DWH -28 Md. Ali Saheb Rajnarayonpur

UBJ - 03 TBC - 01 1999 Nov 10 7.0 <0.03 304 198 <5 0 3 20.06.01

DWH -29 Md. Torab Ali Rajnarayonpur

UBJ - 03 TBC - 01 1999 Dec 11 7.1 <0.03 269 175 <5 0 1 20.06.01

DWH -30 Md. Sattar Sheikh Sibpur UBJ - 03 TBC - 01 1999 Nov 10 7.3 <0.03 214 139 <5 0 0 20.06.01DWH -31 Md. Ahmed Ali Sibpur UBJ - 03 TBC - 01 1999 Dec 9 7.2 <0.03 198 129 <5 0 0 20.06.01

20

DWH -32 Md. Mirza Ruhul Amin Aminpur UBJ - 03 TBC - 01 1999 Dec 15 7.0 <0.03 282 183 <5 0 2 20.06.01DWH -33 Md. Harun Uddin Aminpur UBJ - 03 TBC - 01 1999 Dec 12 7.0 <0.03 322 209 <5 0 1 20.06.01DWH -34 Md. Hosen Sheikh Aminpur UBJ - 03 TBC - 01 1999 Nov 14 7.5 <0.03 187 122 <5 0 1 20.06.01DWH -35 Imam Mirjapur Jame Mirzapur UBJ - 03 TBC - 01 1999 Nov 12 7.1 <0.03 189 189 <5 0 0 20.06.01DWH -36 Md. Motaleb Hossain

KhasAminpur UBJ - 03 TBC - 01 1999 Dec 11 7.2 <0.03 340 222 <5 0 2 20.06.01

DWH -37 Md. Chad Ali Kash Aminpur UBJ - 03 TBC - 01 1999 Nov 14 7.0 <0.03 241 157 <5 0 1 20.06.01DWH -38 Md. Akkas Ali Aminpur UBJ - 03 TBC - 01 1999 Nov 10 7.0 <0.03 342 222 <5 0 0 20.06.01DWH -39 Md. Sahabuddin

MasterRajnarayonpur

UBJ - 03 TBC - 01 1999 Nov 10 7.0 <0.03 305 198 <5 0 5 20.06.01

DWP -40 Mukul Malitha Ruppur UIP - 01 TIC - 02 2003 Jan 40 7.5 <0.03 202 131 <5 0 1 25.01.03

2

? Soignet, Steven L. and Peter Maslak, Zhu-Gang Wang, Suresh Jhanwar, Elizabeth Calleja, Laura J. Dardashti, Diane Corso, Anthony DeBlasio, Janice Gabrilove, David A. Scheinberg, Pier Paolo Pandolfi, Raymond P.Warrell, Jr.Complete Remission after Treatment of Acute Promyelocytic Leukemia with Arsenic Trioxide .The New England Journal of Medicine, Vol. 339, No. 19,November 5, 1998.3

? Pharmacy: a look back at the past and a vision for the future , Pharamceutical Society of Australia, available at: http://www.psa.org.au/ecms.cfm?id=433

4 E.A.C. Crouch and Richard Wilson, "Interspecies Comparison of Carcinogenic Potency," J. Tox. and Environ. Health, 5:1095-1118, 19795

? Venomous Earth Andrew A Meharg Macmillan publishers 208pp $29.95;L16.99 (2005)6

? Britsh Geological Survey 2000 report available on line at http://www.bgs.ac.uk/arsenic/:7

? Yu, Winston H., and Charles M. Harvey. Arsenic in groundwater in Bangladesh: A geostatistical and epidemiological framework for evaluating health effects and potential remediesWater Resources Research, 39(6), 1146, June 2003.8

? Report of British Geological Survey available at: http://www.bgs.ac.uk/arsenic/

9 Data from the National Arsenic mitigigation Information Center: Available at: http://www.bamwsp.org/Survey%20Results.htm10

? WASA report of 2003

11 National Policy Report

12 Hutchinson, J. (1888)Diseases of the skin: On some examples of Arsenic-keratosis of the skin and of Arsenic-Cancer. Transactions of the Pathological Society of London 39:352-363, 1888.

13 Hutchinson, J. 1887.Arsenic cancer.Br Med J, 2:1280-1281. 14 Neubauer, 0. 1947.

21

(MalithaparaDWP -41 Mrs.Salina Khatun Ruppur

(BiswasparaUIP - 01 TIC - 02 2003 Jan 37 7.0 <0.03 172 112 <5 0 3 25.01.03

DWP -42 Mrs.Samshunnahar Ruppur (Charabottala

UIP - 01 TIC - 02 2003 Jan 53 7.1 <0.03 198 127 <5 0 0 25.01.03

DWP -43 Mrs.Rashida Khatun Babulchara UIA - 02 TIC - 02 2003 Jan 48 7.1 <0.03 211 137 <5 0 1 25.01.03DWP -44 Md.Harunar Rashid Durgapur USA - 01 TSC - 03 2003 Jan 28 7.4 <0.03 222 144 <5 0 3 25.01.03DWP -45 Mrs.Samshunnahar Gopalpur USK - 01 TShC -

052003 Jan 20 7.0 <0.03 282 183 <5 0 2 25.01.03

DWP -46 Md.Abdul Momin Khan Sayedpur (Dangapara)

USA - 01 TSC - 03 2003 Jan 35 7.2 <0.03 298 194 <5 0 5 25.01.03

DWP -47 Md.Mojibur Rahman Ahmedpur USA - 01 TSC - 03 2003 Jan 32 7.3 <0.03 301 196 <5 0 0 25.01.03DWP -48 Md. Khorshed Alam Koromja UBK - 04 TBC - 01 2003 Jan 28 6.9 <0.03 314 204 <5 0 1 25.01.03DWP -49 Md.Mamunur Rashid Sayedpur

(Ujanpur)USA - 01 TSC - 03 2003 Jan 32 7.1 <0.03 382 248 <5 0 3 25.01.03

DWP -50 Md.Zinna Ahmedpur USA - 01 TSC - 03 2003 Jan 30 7.4 <0.03 203 132 <5 0 4 25.01.03DWP -51 Md.Azim Uddin Bhabanipur UBR - 02 TBC - 01 2003 Jan 28 7.4 <0.03 168 109 <5 0 1 25.01.03DWP -52 Md.Badsha Master Durgapur USA - 01 TSC - 03 2003 Jan 28 7.0 <0.03 321 209 <5 0 2 25.01.03DWP -53 Sree Nironjan Kumar Sagorkandi UBM - 01 TBC - 01 2003 Jan 35 7.1 <0.03 354 230 <5 0 0 25.01.03

Arsenical cancer; a review.Br J Cancer, 1:192-25115

? Tseng, W.P and H M Chu, S W How, J M Fong, C S Lin and S Yeh:Prevalance of skin cancer in an endemic area of chronic arsenicism in Taiwan .Journal of the National Cancer Institute, 40 (3):453-463, 1968.

16 Tseng, W.P.: Effects and dose response relationships of skin cancer and Blackfoot disease with arsenic. Environmental Health Perspectives, 19:109-119, 1977.17

? Saha KC, Arsenicosis in West Bengal: 2002 Sadananda Publishers 5/1, Mamanath Mazumdar Street Kolcata, 700009)18

? Chen, C.J., Y.C. Chuang, T.M. Lin, and H.Y. Wu. 1985.Malignant Neoplasms Among Residents of a Blackfoot Discase-Endemic Area in Taiwan:High-Arsenic Artesian Well Water and Cancers.Cancer Res, 45:5895-589919

? 6th Report on Arsenic Removal Plants: July 2004 Part B. Followup Study on 20 ARPs found to be functional in March 2004 School of Environmental Studies (SOES) Jadavpur University, Kolkata- 700032, IndiaWebsite: www.soesju.org 20

? Report of Groundwater Task Force Government of Bangladesh, Chairman Dr S.K.M.Abdullah. 2002.21

? WHO table of dug well recommendations http://www.who.int/water_sanitation_health/dwq/wsh0306tab8.pdf22

? Report of Bangladesh Arsenic Mitigation Water Supply Project http://www.bamwsp.org/news5.htm26

? The delagua coliform bacteria measuring kit from the Robens Centre, University of Surrey UKhttp://www.robenscentres.com/delagua/index.cfm27

? The Jal-Tara pollution measuring kit from Clean India in New Delhai Indiahttp://www.cleanindia.org/jaltarakit.htm

22

DWP -54 Md.Raton Chowdhuri Arifpur UPM - 04 TPC - 04 2003 Jan 15 7.3 <0.03 265 172 <5 0 7 25.01.03DWP-55 Md. Abdul Awal Bhabanipur UBR - 02 TBC - 01 2003 Jan 27 7.0 <0.03 312 203 <5 0 5 25.01.03DWP -56 Sree Sudha Ranjan Shagorkandi UBM - 01 TBC - 01 2003 Jan 26 7.2 <0.03 255 166 <5 0 8 25.01.03DWP -57 Md.Rabiul Islam Char Ruppur UIP - 01 TIC - 02 2004 Jan 24 7.3 <0.03 265 172 <5 0 2 28.01.04DWP -58 Md.Zahidul Haq Char Ruppur UIP - 01 TIC - 02 2004 Jan 25 7.0 <0.03 346 225 <5 0 1 28.01.04DWP -59 Md.Shahjahan Char Ruppur UIP - 01 TIC - 02 2004 Jan 25 7.3 <0.03 269 175 <5 0 4 28.01.04DWP -60 Md.Iddris Ali Arippur UPM - 04 TPC - 04 2004 Jan 39 7.0 <0.03 187 122 <5 0 2 28.01.04DWP -61 Md.Shamim Hossain Arippur UPM - 04 TPC - 04 2004 Jan 27 7.4 <0.03 340 221 <5 0 1 28.01.04DWP -62 Md.Mizanur Rahman Bishawnathp

urUBJ - 03 TBC - 01 2004 Jan 27 6.9 <0.03 241 157 <5 0 3 28.01.04

DWP -63 Mrs.Shahanara Lipi Dariapur USA - 01 TSC - 03 2004 Jan 25 7.1 <0.03 305 198 <5 0 4 28.01.04DWP -64 Md.Abul Raja Birahimpur USA - 01 TSC - 03 2004 Jan 28 7.3 <0.03 202 131 <5 0 0 28.01.04DWP -65 Md.Habibur Rahman Rajnaraynpur UBJ - 03 TBC - 01 2004 Jan 24 7.2 <0.03 211 137 <5 0 0 28.01.04DWP -66 Md.Raij Shikder Bhuya Para UBR - 02 TBC - 01 2004 Jan 25 7.2 <0.03 282 183 <5 0 5 28.01.04

23