It is now widely recognized that the world is heading for a water crisis of unusual dimensions in the next 2 decades. Several countries, including parts of India and China, with a population of 1 billion people, would face absolute scarcity of water by 2025. By that time the population of the SAR (South Asia Region - Bangladesh, India, Nepal and Sri Lanka) will top 1.6 billion, with as many as 40% living in urban areas (a figure currently less than 25%). The demand for potable water is under pressure from different factors, including contamination, a matter of serious concern.
India has 23 metropolitan cities (with a population of over 1 million) and 5 mega cities (with a population of over 5 million). Less than half of urban India has access to a sewage disposal system. Most of the existing collection systems discharge directly to the receiving water without treatment. Garbage, domestic or otherwise, is directly dumped into water bodies or roadside, which often later be washed into streams and lakes. Little surprise then that a recent study by the Society for Clean Environment (SoCleen) showed that a significant percentage of water in many parts of Mumbai city was unpotable.
This vulnerable environment requires special attention and the solution of such complex and interdisciplinary problems call for an integrated water resources management approach. But there has been very little research into the hydrology of urban areas. In India, contamination is poorly studied, and remedies are even less understood.
Conventional treatment of drinking water consists of a combined process of screening, coagulation, sedimentation, filtration and disinfection. This process has been successfully used for many years. It has virtually eliminated outbreaks of water borne-diseases such as cholera and typhoid in developed countries. The Quality Criteria of Drinking Water, prescribed by the Indian Standards Institute (IS: 10500-1989) and the Indian Council of Medical Research are exacting and exhaustive. Besides detailed standards of physical and chemical quality, linked to numerological and other parameters like odour and colour, the standards of Bacteriological Quality in the Water Distribution System demand:
- Throughout the year, 95% of samples should not contain any coliform organisms in 100ml.
- No sample should contain E.Coli in 100 ml.
- No sample should contain more than 10 coliform organisms per 100 ml and
- Coliform organisms should not be detectable in 100 ml of any two consecutive samples.
But given water's many uses, not all water requires the same level of treatment. For example, water for gardening need not be treated to the same level as water for drinking. But experts believe (as said at the Vision 2025 : Jaipur Declaration on Water Quality Management, in April last year) that reducing standards for some uses and not others would entail greater risks. Supplying different varieties of water for different commercial uses or for different consumers would be much more expensive than supplying the same quality of water for all purposes.
Furthermore, freeing water from every agent that can cause any health disorder is an impossible standard that can never be reached in practice. The WHO has framed guidelines for levels of microbial contaminants and 128 chemicals that can be hazardous to human health. These guidelines are intended for use by national authorities as a basis for development of drinking water standards and regulations appropriate for their own socioeconomic and risk situations. The WHO Guidelines for Drinking-Water Quality is intended for use as a basis for the development of national standards in the context of local or national environmental, social, economic, and cultural conditions.
Some countries have gone beyond the WHO and set more rigorous national standards and regulations for all categories of microbiological, chemical and radiological contaminants and for physical characteristics, such as odour, taste and clarity. The principal objective of such standards and regulations is to reduce the quantity of contaminants in drinking water to levels that are both effective and efficient in protecting public health. Effectiveness is often a matter of technology; efficiency balances costs with benefits. Biological models, as well as simpler techniques such as the benchmark approach, are all for better use of data to determine safety and acceptable risk.
But most countries principally rely on assessments made by the WHO. India and Sri Lanka have adopted the WHO guidelines which, if strictly enforced, are adequate to ensure reasonably safe drinking water. The government is the supplier of water in these countries.
How well have the well-intentioned rules been met nationwide? A look at some different studies shows discouraging, even shocking results.
An undated study of all water supply schemes in Swajal villages in seven districts (Banda, Chitrakoot, Hamirpur, Jhansi, Jalaun, Lalitpur, and Mahoba) of the Bundelkhand region showed that some of the possible reasons for contamination of water were broken hand-pump platforms, poor drainage, unhygienic surroundings, the improper functioning of the chlorinator and so on.
The study by the Society for Clean Environment (SoCleen) in July 2003 showed that a significant percentage of water in many parts of Mumbai city was unpotable and contaminated with excessive bacterial pollution. The study was funded by the Mumbai Metropolitan Regional Development Authority (MMRDA). Besides siting an alarming number of samples unfit for drinking, the study found levels of bacterial contamination upto 20% in many of the municipal wards. Fecal coliform (bacteria found in excreta), an important indicator of water safety, was several hundred times higher than the norm. For example, samples from Chembur, Masjid, Parel-Dadar, Mulund and Jogeshwari touched 1600 fecal coliform (fc) per 100 ml of water. Safety norms in India set the limits at 10 fc per 100 ml. The WHO says that there should be no fecal coliform in drinking water.
Some studies are available from the southern state of Kerala. Sample surveys have shown that majority of wells in the State suffer from bacteriological, heavy metal, pesticide and bacterial contamination. Although several studies conducted by the Centre for Water Resources Development and Management (CWRDM) during 1994-1997 indicated chemical and biological contamination in ground and surface water sources, and random samples confirmed this, systematic data was absent in Kerala. A sample survey of groundwater sources conducted by the CWRDM in Palakkad district in 1977 showed that more than 50 per cent of the sample wells were biologically contaminated with high coliform density. Improper location of wells and nearness to pollution sources were observed to be the main reasons for the contamination. The study also showed presence of chemical pollutants such as chloride, fluoride, iron and nitrate in groundwater. Percentage of contaminated samples was found to be the highest in Kasaragod district followed by Thiruvananthapuram. Reports of analysis of water samples from Idukki district showed high concentrations of iron and coliforms. Studies on water quality of ten rivers of the State by the Kerala Water Authority showed chemical and biological contamination from agricultural discharge, domestic sewage and industrial effluents.
In Chennai, there have been sporadic news reports on water contamination in different parts of the city. This was brought to light more due to citizens complaints than any sustained checking system. It is worth noting that in these instances piped water had become visibly and irrefutably contaminated even to the naked eye. Residents of New Washermanpet and several stretches of the Tiruvottiyur High Road in North Chennai had been provided piped water with markedly grey colour and rust particles for more than two weeks in September this year, raising fears of high degree of contamination. The situation was likewise in the Wards 4 and 6 of the Chennai Corporation. The local Metrowater officials said the main reason for the coloured water supply was the flushing out operations undertaken at another pumping station. Confusion was reported even among Metrowater officials as to whether the contaminants were from flushing operations or other leaks. In May this year, citizens expressed outrage under the aegis of the Water Exnora (a civic movement headed by NGO Exnora International). Several city residents lodged complaints of contamination in piped supply, saying water was black in colour and gave off a foul smell.
The situation has been grave enough for sometime. A high-level international conference on water quality management was held in April 2002 in Jaipur. Sponsored by the International Life Sciences Institute, the Union Govt. of India and the Govt. of Rajasthan, UNICEF and the United States - Asia Environmental Partnership (US-AEP), it had 180 delegates from India and abroad.
And experts agree that monitoring and surveillance are the weakest links in the South Asia Region. Laboratory facilities for analysis of water quality are poorly equipped. Public health engineering departments, Central and State Ground Water Pollution Boards, Central Water Commissions, and other groups are all involved with assessing water quality. But shared responsibilities leave room for inefficiency, negligence, and delays. In addition, these groups seldom coordinate planning or future monitoring of water quality. These are surely murky waters.