Clean Drinking Water: A Rare Commodity
By Allan Weatherall
According to a 1999 report of the Secretary General of the UN on global water resources, the world is facing a worsening series of local and regional water quantity and quality problems in the years ahead. The countries which will be worst effected are those which lack the necessary financial resources for sustainable development and management of water resources. The 2006 drought in Australia has shown that even developed countries are not immune from the economic ravages of water shortages and effective planning is required to ensure that long term supply of water is guaranteed.
Today more than one-fifth of the world’s population do not have access to safe drinking water and it is estimated that at any one time half of the people in developing countries suffer from water and food related diseases. The World Health Organisation estimates that five million people die each year from diseases caused by unsafe drinking water.
Surprisingly, water contamination can be a bigger problem in regions where rainfall is plentiful. Excessive rain often causes pit latrines to overflow into water supplies which are used for domestic purposes. Micro-organisms found in human and animal wastes contain a wide range of bacteria, viruses, protozoa and other disease-causing organisms. But even in highly developed countries, run-off from fertilisers and detergents is causing excessive algae growth and leading to a decline in water quality. High nitrate levels in drinking water decrease the oxygen carrying capacity of haemoglobin in blood, which can threaten the health of infants. A UN study says that nitrate pollution will likely be one of the most pressing water quality problems in the coming decade.
Underground water currently supplies 30 percent of the world’s population and is the main or only source of water for rural dwellers in many parts of the world. For more than 20 years tube wells have been a cheap and effective way of avoiding outbreaks of diarrhoea and cholera. But the alarming problem of underground water contamination is now emerging. Heavy metals are found naturally in soil and water, but increased worldwide production and use by industry have released large amounts into the environment and are filtering into the underground water table. Babar Kabir, a hydrologist with the World Bank, estimates that 18 million Bangladeshis are now affected by arsenic from underground water, with some estimates that more than 50 million people are at risk.
In addition to the problem of contamination, underground water supplies are being heavily overused and water levels have dropped by tens of metres in some regions. This makes it difficult and expensive for people to access the water. When water levels drop, many people are forced to use lower quality underground water sources, some of which contain natural contaminants, increasing their risk of disease.
The World Bank has estimated that about $600 billion needs to be invested worldwide to repair and improve existing water delivery systems. It is estimated that about half of the available drinking water in existing systems is lost due to leakage, illegal hookups and vandalism. The UN Secretary’s report on global water resources stated that to provide universal [water] coverage only in the urban areas of the most needy regions (ie: Africa, Latin America and South-east Asia) $54 billion would be needed. The report went on to say that “There is no sign this amount of funding will be made available in the near future in the form of reallocation of internal government spending in nations, or in development assistance from abroad.”
Given these numerous problems — the growing problem of underground water contamination; the over utilisation underground water resources; the prohibitive cost of major water infrastructure; the contamination of rivers and reservoirs from chemical pollutants — it is now critical for the world’s governments and development organisations to rethink their approach to water supply.
Rainwater harvesting in the developing world is yet an untapped and unexplored field. If the economic and political resolve can be found to explore new and simple technologies, and to implement affordable rainwater harvesting systems on a wide scale, millions of lives could be saved and untold human suffering prevented. In non-industrial regions the cleanest water is always that which falls freely from the sky — rain. The natural water cycle is very effective in screening out contaminants and making water fit for human consumption. The widespread utilisation of rainwater can relieve demand on underground delivery systems and make the cleanest water in the world available to the poorest people in the world.
Saturday, November 25, 2006 printer friendly version | 12127 reads
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