Ten Million Hand Pumps
From the 1970s, aid agencies and the Bangladeshi government moved a country off pond water and onto hand-pumped tubewells, and deaths from waterborne disease fell steeply. Then, in 1993, the water turned out to contain arsenic — not from any spill, but from the sediment the delta is made of.
In villages across the delta the spout of a hand pump is painted, and the colour is the whole of the public health message. Green means the water tested below the national limit for arsenic. Red means it did not, and that the household should walk to somebody else's pump. Much of the paint went on between 1999 and 2005 and a good deal of it has since flaked, faded or been painted over, and a well that tested green two decades ago has not necessarily stayed green.
The pumps themselves were the great public health success of the late twentieth century in Bangladesh, and then they were the great public health disaster, and both descriptions are accurate. Very little else in development has reversed itself so completely, so fast, using exactly the same infrastructure.
The switch that worked
From the 1970s UNICEF and the Department of Public Health Engineering pushed shallow hand-pumped tubewells across rural Bangladesh, for an entirely sound reason. People were drinking from ponds, ditches and rivers, and that water carried cholera, typhoid and the rest of the diarrhoeal catalogue that was then killing very large numbers of Bangladeshi children. Groundwater fifteen or thirty metres down was pathogen-free. The programme was cheap, it was popular, and it was copied everywhere. Within two decades there were something on the order of ten million tubewells in the country, and the great majority of them had been sunk not by any agency but privately, by families and village drillers who had seen the idea and could afford the pipe. Child mortality from waterborne infection fell steeply. That part never stopped being true.
What was in the water
Arsenic was confirmed in Bangladeshi tubewell water in 1993, some years after it had turned up across the border in West Bengal. It is geogenic — it comes out of the Himalaya in the sediment the rivers have been laying down here for millennia, and it dissolves into the groundwater where conditions are chemically reducing, which they are through much of the shallow delta aquifer. There was no spill and no culprit. It also has no colour, no taste and no smell, which is why it went unnoticed for twenty years while the wells were being celebrated. The national survey carried out by the British Geological Survey with the DPHE found that of 3,534 tubewells sampled across the country, 46 per cent exceeded the World Health Organization guideline of 10 micrograms per litre and 27 per cent exceeded Bangladesh's own standard of 50. The harm is chronic rather than acute: skin lesions after years, then raised rates of cancers of the skin, bladder and lung, and cardiovascular disease. An article in the Bulletin of the World Health Organization in 2000 called it the largest mass poisoning of a population in history, and the phrase has stuck because nobody has produced a better one.
Nobody poisoned Bangladesh. The arsenic was already there; what the twentieth century added was ten million ways to drink it.
Red and green
The response was a national screening campaign that tested roughly five million wells and painted the spouts. As a first move it was the right one — it is fast, it needs no literacy, and it tells a household something actionable on the day. As a permanent system it has obvious holes. Wells are re-sunk and new ones are drilled constantly, by families, without anybody testing them. Arsenic concentration in a single well can change over time. A red well in a hamlet where the nearest green one is a fifteen-minute walk away, along a bund that goes under water for three months of the year, past a household you are not on speaking terms with, gets used. And the deeper wells that solve the problem properly — below about 150 metres, into older sediment that is not releasing arsenic — cost far more than a family sinks on its own, which turns the fix into a question of who gets one.
The case that was struck out
One attempt to find somebody legally responsible reached the House of Lords. The British Geological Survey had carried out a hydrochemical reconnaissance in Bangladesh in 1992, funded by British aid, as part of a project concerned with irrigation and fish farming rather than drinking water. It tested groundwater for a long list of elements and did not test for arsenic. Mr Sutradhar, who had arsenical poisoning, argued that the report had induced the Bangladeshi authorities not to act. On 5 July 2006 the Lords struck the claim out, holding that BGS owed him no duty of care: it had no control over Bangladesh's water supply and had never assumed responsibility for it. The judgment is about proximity in the law of negligence and it decides nothing at all about whether testing for arsenic would have been a sensible thing to do in 1992. It does mark the outer limit of what litigation was ever going to deliver here.
Twenty million
Human Rights Watch reported in 2016 that around 20 million people in Bangladesh were still drinking water above the national standard, and made a second, sharper allegation: that the deep tubewells intended as the remedy were being allocated through local political patronage rather than by where the contamination was. A paper published the same year in the Journal of Water, Sanitation and Hygiene for Development — van Geen and colleagues, working across 915 intermediate and deep wells in a single 180-square-kilometre block — found the same pattern of inequitable allocation, and noted that the households able to divert a public well onto their own land tended to be the ones with a claim on somebody. Neither finding is a reason to romanticise what came before. The alternative to a contaminated tubewell is not clean water; it is the pond, and the pond kills children faster than arsenic kills adults. What Bangladesh is left with is not a crisis with an end date but a maintenance obligation without one — retesting millions of privately owned wells, indefinitely, in a country of 170-odd million people where anybody with a few thousand taka can drill another. For a visitor, none of this is a personal risk. Bottled and filtered water is sold on every corner and the cost of avoiding the problem entirely is trivial, which is precisely the difference between the visitor and the household whose pump is the wrong colour.