Safe Drinking Water for All - Containing Arsenic Contamination: An NGO Initiative
Courtsey: Daily Star July 16, (www.dailystarnews.com).
The author is working with the "NGO Forum for Safe Drinking Water Supply and Sanitation", an NGO working on environmental issues.
by Sanchia Nishat Chowdhury
More than 90 per cent of the people of Bangladesh get their drinking water from the million plus tube-wells that were installed for the anti-diarrhoea campaign to reduce water borne diseases. Now several are dispensing arsenic laced water with the result that many people are no showing signs of arsenic related diseases. This situation has accelerated in the past two years to a degree such that currently 44 districts of the 64 in Bangladesh are affected by arsenic, and 220,000 people, as of June 1998 are supposedly at risk.
Arsenic is a metalloid substance that is commonly found in ground water, and is being spread through the use of deep tube-wells, which have been targeted as the origin of chronic arseniasis. The shallow tube-well waters in some areas of Chandpur, Barisal, Jessore, and Kushtia are heavily contaminated with arsenic ranging from 0.01mg to 3.0 mg per litre. The waters of 56 per cent of tube-wells are above the World Health Organization maximum tolerable limit of 0.05 mg/1. In these areas, the intensely contaminated tube-wells have been sealed by the Department of Public Health Engineering without giving them an alternate safe drinking water facility.
Concerned organizations have, over the years, encouraged the use of pump technologies for safe ground water access. The rationale being this emphasis was that ground water was affordable, and close to the community. Groundwater was also safe from pollutants and biological contamination. However, the start of the Green Revolution in the 1970s, saw the demand for excessive amounts of water for agricultural use to feed the growing population.
This, in turn, meant an increase in the installation of tube-wells, both power and hand driven, and enormous quantities of water were being drawn out from various underground sources. While the amount of water being lifted for drinking purposes is recharged naturally, the recent intensive pumping out of water for other uses has brought the underground arsenic into the tube-wells and pumps. Noted specialists have expressed their opinion regarding the cause and effect of the arsenic laced water being spread through the ground water, via tube-wells and pumps, emphasizing the severity of the contamination.
Since the threat of arsenic is still relatively new, the community is unaware of the arsenic situation and the threat it poses. They refuse to believe in the presence of arsenic, because most have not yet been afflicted with the symptoms of arseniasis. The only people cognizant of this vital information are at a loss what to do. A programme of information dissemination has yet to be undertaken, and steps to inform the people, and take measures to combat the situation, are only in the beginning stages. Those whose drinking supply have been tested and know of the arsenic contents turn a blind eye to it.
While there is no substitute remedy available, the people have no choice but to drink the contaminated water. In most cases, there is no availability of safe water. Few eat fresh fruits and vegetables in the hope that the nutrition will lessen their susceptibility to arsenic diseases. But most of the poor folk in the villages cannot even utilize this measure.
Until an alternate is suggested, the people will continue to drink arsenic laced water. NGO Forum, in its principle role of advocating for safe water, is embroiled in the middle of this dynamic issue. It has been targeted as the country's chief patron of the NGOs dealing in water supply and sanitation. Its programme of encouraging the installation and use of tube-wells, and pumps for safe water which are dispensing the contaminated water, has come under public scrutiny.
The Forum faces the dilemma of whether to seal off the tube-wells, thus exposing millions of people to the risks and hazards of diarrhoea from unsafe water, or to implement a system of purification, yet unknown, the technology for which may both be impractical and expensive for the rural masses. Over the past decade the people were taught not to drink pond water, which was very harmful and unsanitary. The installation and use of tube-wells were enforced. Habituating the people to drink tube-well water was the result of a long and arduous process, getting them to change once again may take another decade which would prove to be too long.
NGO Forum is attempting to deal with the situation, the best it can. It is supporting its partner NGOs in undertaking the biennial testing and inspection if its tube-wells, and where arsenic levels exceed the WHO safety levels of 0.05mg/1, the targeted tube-wells, are marked. In addition, testing is also undertaken during the installation of new tube-wells, and where there is a probable risk of arsenic contamination, plans for installation are abandoned.
Marking the tube-wells was a more viable alternative than a complete seal-off, for, while these wells cannot be used for drinking or cooking, they can be used for other purposes. However, this also poses a problem. Almost 100 per cent use of tube-well water is for drinking and cooking purposes. These is little effect of telling the people not to use their chief source of water for internal use, while at the same time not being able to suggest the substitute. It is this search for substitute methods of obtaining water which is hindering the Forum and its partners' work.
In its role of familiarizing the rural folk with the arsenic situation, NGO Forum has incorporated arsenic issues in its regularly conducted training courses' agenda. These courses benefit not only the partner NGOs, but also the community people, and it is encouraged that these people further disseminate the information among the relevant persons. The training course provides valuable information about the arsenic compound, its spread, effects, and possible prevention. Problems arise because most arsenic symptoms are confused with malnutrition, and it is further true that most older people, 40 years and above, deficient in Vitamins A, C, and E are most susceptible to arsenic related diseases.
In most regions of the country, an effective combative programme has still to be undertaken. NGO Forum, declares that "the strategy of telling all the NGOs to seal off their tube-wells is too drastic a measure. All the tube-wells are not supplying arsenic, and until an alternative is found, sealing off all the tube-wells is too extreme a step. There is still not widely accepted belief as to the root cause of arsenic pollution. There is even much doubt as to the currently publiszed information about the arsenic situation. Hence, so far, NGO Forum will abide by its stand of merely testing and marking the affected tube-wells, and at the same time, continue its research into the cause and solution of this situation.
NGO Forum's present initiatives in tackling the arsenic situation are immediate and temporary measures. It is also working with different, more permanent, surface water treatment methods, such as pond sand filtration system, rain-water harvesting, and others, which are safe from arsenic. These treatment methods are currently being undertaken in the coastal areas, and the areas heavily affected by arsenic.
The type of treatment required depends on the physical, chemical and biological characteristics of the raw water. Turbidity, fetidity, and pungency may be some of the physical characteristics of pond water, due to the decaying of excess organic matter, living algae and other microscopic orgnism. It may also contain other contaminants of air, water, and land. The pond sand filter is a very simple and low cost technology, which is appropriate for purifying pond water in the coastal belt.
Filtration is a process of water purification in which water from a sedimentation tank is allowed to pass through a bed of filtering media, usually sand and khoa, and the filtrate is collected in a storage tank through an under-drain system. The filter media is very efficient in removing colour, odour, turbidity, Iron, and manganes. The PSF system ensures, that
a) the filtered water will be safe to drink,
b) the water will be clear and clean,
c) the iron content will be at a minimum,
d) the salinity will be minimal,
e) the water will be palatable, and
f) the water will be suitable for domestic use.
The rain-water harvesting system is also another viable alternative to the arsenic situation. Such rain water collection systems have been used since ancient times and evidence of roof catchment systems date back to early Roman times. The technology also has a long history in Asia, where rainwater collection practices can been traced back almost 2000 years in Thailand. The world's largest rainwater tank is probably the Yerebatan Sarayi in Istanbul Turkey. It measures 140m by 70m and has a capacity of 80,000 cubic meters.
In Bangladesh, traditional rain water collection have been used in the coastal regions and Hill Tract areas from many years. People used large earthen pots to store rain water and use in the dry spells. The problems with ground and surface water supplies such as salinity, contamination, etc. have lead to the development of the rain water harvesting system.
The two major components in a rain water harvesting system are the "catchment" and the "storage". Roof tops are most commonly used as the catchment. The rain water from C I sheet or thatched roof is collected into a suitable storage or tank by means of a gutter system. A gutter is a device to work as an inlet structure for collecting the water which runs off the sloped or horizontal roof surface. Conventional gutters are normally used along the length of the roof, and clamped to the edge with a wire rope. The rain water harvesting system is affordable, reliable and easily constructed. It provides water which is clean and of good quality.
Although NGO Forum plays an apex role in spreading the use of safe drinking water, and water supply, it should not be left alone in this field of maintaining the existing safe water coverage. All the sectoral organizations working in this capacity should be encouraged to contribute in ensuring safe water. It is imperative that immediate steps be taken to research into the causes of water pollution, and ways of alternate safe water technologies. The writer works for NGO Forum for Safe Drinking Water Supply and Sanitation
