Wednesday, October 23, 2019
Availability of Drinking Water
INTRODUCTION Drinking water or potable water is water of sufficiently high quality that it can be consumed or used without risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually consumed or used in food preparation. Clean drinking water has yet to be completely recognized as a basic human right. While water plays a vital role in every aspect of life, some do not realize the gravity of the shrinking clean water sources. When unclean water is consumed, it can cause serious illnesses, sometimes leading to death. According to statistics provided by the World Health Organization (WHO), about 1. 1 billion of the world's 6 billion people do not have access to clean drinking water sources. Drinking Water is essential to the survival of all organisms,water has always been an important and life-sustaining drink to humans. Excluding fat, water composes approximately 70% of the human body by mass. It is a crucial component of metabolic processes and serves as a solvent for many bodily solutes. Health authorities have historically suggested at least eight glasses, eight fluid ounces each (168 ml), of water per day (64 fluid ounces, or 1. 89 litres),and the British Dietetic Association recommends 1. 8 litres. The United States Environmental Protection Agency has determined that the average adult actually ingests 2. 0 litres per day. 70% of the Earth's surface is covered by water. Water is available almost everywhere if proper methods are used to get it. Sources where water may be obtained include: ground sources such as groundwater, hyporheic zones and aquifers. precipitation which includes rain, hail, snow, fog, etc. urface water such as rivers, streams, glaciers biological sources such as plants. the sea through desalination Access to safe water can be measured by the number of people who have a reasonable means of getting sufficient water that is safe for drinking. Availability of safe drinking water is an indicator of the health of a country. A developed country will be more efficient in collecting, cleaning and distributing water to consumers. It is a sad fact but is true that ninety percent of urban sewage in the developing world is discharged into rivers and other water bodies. In the developing world, millions of residents lack a source of safe drinking water near their homes. People get safe drinking water from various sources such as household connection, borehole, protected dug well, public standpipe etc. But the Question that arises is : â⬠Does everyone has safe drinking water available? â⬠Availability of drinking water scenario in India is very Bad as compared to other countries like USA, England, China etc. as can be observed from the underlying table: Countries Amount Finland:100% Australia:100% Netherlands:100% Norway:100% Sweden:100% Switzerland:100% United Kingdom:100% United States:100% Russia:99% Bangladesh:97% Albania:97% Egypt:97% Pakistan:90% Nepal:88% Brazil:87% South Africa:86% India:84% A detailed analysis can be seen in the graph shown : Paste this map over here.. http://www. mapsofworld. com/thematic-maps/safe-drinking-water. htm The availability of Drinking Water is hampered and altered depending upon various factors such as, Drinking Water pollution, Wastage, Demand supply ratios, Treatment methods etc. INDIAN STANDARD SPECIFICATIONS FOR DRINKING WATER Indian Standards has set various limits over different chemical and physical properties of Water, in order to label it as Safe and Drinking Water, a sample of water, lying in the permissible range set as per IS, is safe for drinking. Following are the IS Specifications for Drinking Water : S. NO. Parameter Requirement desirable Limit Remarks 1. Color 5 May be extended up to 50 if toxic substances are suspected 2. Turbidity 10 May be relaxed up to 25 in the absence of alternate 3. pH 6. 5 to 8. 5 May be relaxed up to 9. 2 in the absence of alternate 4. Total hardness 300 May be extended up to 600 5. Calcium as Ca 75 May be extended up to 200 . Magnesium as Mg 30 May be extended up to 100 7. Copper as Cu 0. 05 May be relaxed up to 1. 5 8. Iron 0. 3 May be extended up to1 9. Manganese 0. 1 May be extended up to0. 5 10. Chlorides 250 May be extended up to1000 11. Sulphates 150 May be extended up to 400 12. Nitrates 45 No relaxation 13. Fluoride 0. 6 to 1. 2 If the limit is below 0. 6, wa ter should Be rejected, Max. Limit is extended to 1. 5 14. Phenols 0. 001 May be relaxed up to 0. 002 15. Mercury 0. 001 No relaxation 16. Cadmium 0. 01 No relaxation 17. Selenium 0. 01 No relaxation 18. Arsenic 0. 05 No relaxation 19. Cyanide 0. 05 No relaxation 20. Lead 0. 1 No relaxation 21. Zinc 5. 0 May be relaxed up to 10. 0 22. Anionic detergents (MBAS) 0. 2 May be relaxed up to 1 23. Chromium 0. 05 No relaxation 24. Poly nuclear aromatic Hydrocarbons ââ¬â ââ¬â 25. Mineral oil 0. 01 May be relaxed up to 0. 03 26. Residual free chlorine 0. 2 Applicable only when water is chlorinated 27. Pesticides Absent ââ¬â 28. Radioactive ââ¬â ââ¬â REQUIREMENT V/s. AVAILABILITY Water. If you've got it, you probably take it for granted. But a quick scan of the globe ââ¬â and a chat with the tiny group of researchers who are obsessed by fresh water ââ¬â both indicate that water shortages are looming. And they aren't necessarily in the future, either. You don't miss your water, an old blues sage wisely said, 'til your well runs dry. Down here on planet Earth, the well is starting to run dry. We've seen projections that three billion people ââ¬â half of today's population ââ¬â will be short of water in 2025. The Earth has a finite supply of fresh water, stored in aquifers, surface waters and the atmosphere. Sometimes oceans are mistaken for available water, but the amount of energy needed to convert saline water to potable water is prohibitive today, explaining why only a very small fraction of the world's water supply derives from desalination. The Millennium Development Goal of halving the proportion of people without access to safe drinking water between 1990 and 2015 is a target we are aiming for. Although some countries still face enormous challenges. Rural communities are the furthest from meeting the 2015 MDGs drinking water target. Globally only 27% of the rural population has water piped directly to their home and 24% rely on unimproved sources. Of the 884 million people without access to an improved water source, 746 million people (84%) live in rural areas. Sub-Saharan Africa has made the least progress in improved water sources since 1990, improving only 9% to 2006. In contrast, the Eastern Asian region saw a dramatic drop from 45% to 9% reliance on unimproved water in the same time period. The shortage of water in our country is slowly affecting the lives of people as well as the environment around them. Some of the major issues that need urgent attention are: â⬠¢ As a result of excessive extraction of ground water to meet agriculture, industrial and domestic demands, drinking water is not available during the ritical summer months in many parts of the country. â⬠¢ About 10 per cent of the rural and urban population does not have access to regular safe drinking water and many more are threatened. Most of them depend on unsafe water sources to meet their daily needs. Moreover, water shortages in cities and villages have led to large volumes of water being collected and transported over great distances by tankers and pipelines. â⬠¢ Chemical contaminants namely fluoride, arsenic and selenium pose a very serious health hazard in the country. It is estimated that about 70 million people in 20 states are at risk due to excess fluoride and around 10 million people are at risk due to excess arsenic in ground water. Apart from this, increase in the concentration of chloride, TDS, nitrate, iron in ground water is of great concern for a sustainable drinking water programme. All these need to be tackled holistically. With over extraction of groundwater the concentration of chemicals is increasing regularly. â⬠¢ Ingress of seawater into coastal aquifers as a result of over-extraction of ground water has made water supplies more saline, unsuitable for drinking and irrigation. Pollution of ground and surface waters from agrochemicals (fertilizers and pesticides) and from industry poses a major environmental health hazard, with potentially significant costs to the country. The World Bank has estimated that the total cost of environmental, damage in India amounts to US$9. 7 billion annually, or 4. 5 per cent of the gross domestic product. Of this, 59 per cent results from the health impacts of water pollution (World Bank 1995). DRINKING WATER POLLUTION Availability of drinking water is largely affected by its pollution, which has been leading and will lead to a decrease in its availability in the coming future. Drinking water pollution is a bigger problem than most people realize. While drinking water filters and bottled water has become a staple in our society, most consumers still use unfiltered drinking water for cooking, filling pet water bowls and bottles, and for mixing powdered drink mixes. Drinking water pollution is a big enough problem within our country to warrant the same vigilance as we give other health hazards. There are numerous sources that pile up into serious contamination potential for all drinking water. Whether your water is coming from a well on your property or if you are using ââ¬Å"filteredâ⬠city water sources, the chances that you have a problem with drinking water pollution is quite high. Groundwater testing has shown that in any given area throughout the country as many as 200 variable contaminants have been detected. Long term exposure can create numerous health problems, including lead poisoning. While not every single contaminant is destined to cause a serious health problem or even any health problem at all, you can not count on your local contaminants to be harmless. Agriculture practices are one of the largest sources of groundwater contaminants. The chemical used in controlling bugs and other chemically based treatments run directly into the groundwater supply. Pesticides and poisonous agricultural raw waste can contaminate more than 40% of the surrounding groundwater. Ingress of seawater into coastal aquifers as a result of over-extraction of ground water has made water supplies more saline, unsuitable for drinking and irrigation. Pollution of ground and surface waters from agrochemicals (fertilizers and pesticides) and from industry poses a major environmental health hazard, with potentially significant costs to the country. Another major contributor to drinking water pollution is urban run off. Another human based contribution that needs to be controlled at the source in order to save our drinking water supply. When rain washes urban trash, chemicals, and pollutants from the structures and roadways of populated areas, there is no way for the water to filter itself on its way to the groundwater. Everything from basic trash, cigarette butts, antifreeze, motor oil, gasoline, pesticides, and other daily use products are all contributing factors in groundwater contamination caused by urban run off. Practicing safer disposal practices of automobile chemicals, putting together trash clean up projects, and using environmentally safe household products can help cut down on urban run off pollutants. Lead is one of the most concerning urban run off pollutants, as lead poisoning can cause learning problems, chronic emotional and health issues, and is non-reversible. Drinking lead contaminated water is a serious health problem. Water Treatment Water treatment is the process of removing undesirable chemicals, materials, and biological contaminants from raw water. The goal is to produce water fit for a specific purpose. Most water is purified for human consumption (drinking water) but water purification may also be designed for a variety of other purposes, including meeting the requirements of medical, pharmacology, chemical and industrial applications. It is important to take measures to make available water of desirable quality at the consumer end. That leads to protection of the treated water during conveyance and distribution after treatment. It is common practice to have residual disinfectants in the treated water in order to kill any bacteriological contamination after water treatment. Processes for treatment of drinking water: The combination of following processes is used for municipal drinking water treatment worldwide: Pre-treatment: It consists or removal of large debris such as sticks, leaves, trash and other large particles which may interfere with subsequent purification steps. It also includes treatment of water with soda-ash to remove hardness or chlorine to minimize the growth of fouling organisms on the pipe-work and tanks. pH adjustment: Distilled water has a pH of 7. If the water is acidic, lime, soda ash, or sodium hydroxide is added to raise the pH. Acid (HCl or H2SO4) may be added to basic waters in some circumstances to lower the pH. Making the water slightly basic ensures that coagulation and flocculation processes work effectively and also helps to minimize the risk of lead being dissolved from lead pipes and lead solder in pipe fittings. Flocculation: It is a process which removes any turbidity or color so that the water is clear and colorless and is done by causing a precipitate to form in the water which can be removed using simple physical methods. Coagulants / flocculating agents that may be used include: Iron (III) hydroxide Aluminium hydroxide PolyDADMAC Sedimentation: Water exiting the flocculation basin may enter the sedimentation basin, also called a settling basin. The dimensions of the tank are chosen such that it can lead to maximum particles settling down. As particles settle to the bottom of the basin, a layer of sludge is formed on the floor of the tank. This layer of sludge must be removed and treated accordingly. Filtration: After separating most floc, the water is filtered as the final step to remove remaining suspended particles and unsettled floc. Different types of filters are: Rapid sand filters Slow sand filters Lava filters Disinfection: It is accomplished both by filtering out harmful microbes and also by adding disinfectant chemicals in the last step in purifying drinking water. Different types of disinfections are: Chlorine disinfection Chlorine Dioxide Disinfection Ozone disinfection Ultraviolet disinfection Hydrogen peroxide disinfection Various portable methods of disinfection Solar water disinfection Biological processes are also employed in the treatment of wastewater and these processes may include, for example, aerated lagoons, activated sludge etc. There is no unique solution (selection of processes) for any type of water. Also, it is difficult to standardize the solution in the form of processes for water from different sources. Selection of any of the following methods depends on the scale of the plant and quality of the water. Wastage/Conservation of Water Water is needed for our survival. It is the most important resource for us. So its high time for us to realize this and start conserving water. So we need awareness among people so that each individual puts effort at their level and contribute to the larger cause on the whole. Saving the earth from such a crisis would not be possible without the efforts of each individual. People can start at home by not letting their taps open and by not spilling the drinking water. People should not let their taps run when its not needed. It is important for them to realize that millions of people don't even get access to drinking water. Government needs to implement stricter laws to avoid wastage of water during distribution. Higher fines can be imposed on people who waste water and higher incentives can be given to those conserving water. Recycled water can be used for gardening, washing etc. Due to the current water crisis. Only during times of shortage, do we take emergency measures; saving water should be followed even when there is surplus. If not for the current water shortage, not many would have taken notice of such occasions. During the time when we used to get good rainfall, we never conserved water. A large city needs billions of litres of drinking water every day to service the needs. We will have to make alternate water sources like rainwater harvesting, dig wells and bore wells for our use. The civic corporation should take the initiative to check the broken water pipelines. Such networks rupture occasionally which result in wastage of water every day and should repair it. There should be a specific limit for using water, every society should strictly abide by it should be enforced by societyââ¬â¢s office bearers. Due to leakage to existing drinking water pipelines, every day millions of litres of drinking water is going waste. If wastage is stopped the drinking water supply will improve to some extent. The supply of drinking water is not increasing according to demand. As a result, drinking water scarcity is arising. Urban Water Supply Even though the rate of urbanisation in India is among the lowest in the world, the nation has more than 250 million city-dwellers. Experts predict that this number will rise even further, and by 2020, about 50 per cent of India's population will be living in cities. This is going to put further pressure on the already strained centralised water supply systems of urban areas. The urban water supply and sanitation sector in the country is suffering from inadequate levels of service, an increasing demand-supply gap, poor sanitary conditions and deteriorating financial and technical performance. According to Central Public Health Engineering Organisation (CPHEEO) estimates, as on 31 March 2000, 88 per cent of urban population has access to a potable water supply. But this supply is highly erratic and unreliable. Transmission and distribution networks are old and poorly maintained, and generally of a poor quality. Consequently physical losses are typically high, ranging from 25 to over 50 per cent. Low pressures and intermittent supplies allow back siphoning, which results in contamination of water in the distribution network. Water is typically available for only 2-8 hours a day in most Indian cities. The situation is even worse in summer when water is available only for a few minutes, sometimes not at all. A Stress Situation According to a World Bank study, of the 27 Asian cities with populations of over 1,000,000, Chennai and Delhi are ranked as the worst performing metropolitan cities in terms of hours of water availability per day, while Mumbai is ranked as second worst performer and Calcutta fourth worst (Source: Background Paper ââ¬â International Conference on New Perspectives on Water for Urban & Rural India ââ¬â 18-19 September, 2001, New Delhi. ) In most cities, centralised water supply systems depend on surface water sources like rivers and lakes. Chennai, for instance, has to bring in water from a distance of 200 km whereas Bangalore gets its water from the Cauvery river, which is 95 km away. Where surface water sources fail to meet the rising demand, groundwater reserves are being tapped, often to unsustainable levels. Delhi: The nation's capital is perpetually in the grip of a water crisis, more so during the dry season, when the situation gets particularly worse. As the demand-supply gap widens, more groundwater is being exploited. Of the water supplied by the municipality, approximately 11 per cent comes from groundwater reserves and remaining from the Yamuna river. It is, however, difficult to establish the total quantity of groundwater extracted because a large number of tubewells (owned by individuals, industries and bottled water companies) remain unregistered. In Delhi approximately 13 per cent (Source: Zerah. , M Helene, 2000, Water ââ¬â Unreliable Supply in Delhi, French Research Institute of India) households do not receive water every day and in Rajkot, Gujarat, water availability in April 2000 was only for 30 minutes every alternate day. Rural Water Supply The rural population of India comprises more than 700 million people residing in about 1. 42 million habitations spread over 15 diverse ecological regions. It is true that providing drinking water to such a large population is an enormous challenge. Our country is also characterised by non-uniformity in level of awareness, socio-economic development, education, poverty, practices and rituals which add to the complexity of providing water. Dependence on the state has meant that with the cost of water supply being high and cost recovery being poor, the financial sustainability of water schemes has run aground, and repairs and maintenance is abysmal. With people having no interest in using water carefully, the sustainability of water has itself become questionable. There are serious problems with government drinking water supply schemes. Despite government efforts, the number of ââ¬Ëproblem villages' does not seem to go down, The government has indeed invested heavily on water resources development, which focussed on large-scale irrigation development for increasing green revolution-style agriculture production and drinking water supply programmes. Yet, a large part of the country remains drought-prone. This is because no specific effort has been made to drought-proof rainfed areas which suffer from high rainfall variability from year to year. Role of Government Ministry of Water Resources, Ministry of Urban Development and Poverty Alleviation, Ministry of Rural Development, Ministry of Environment and Forest and Ministry of Health and Family Welfare all have got a different roles to play to provide drinking water of adequate quantity and potable quality to meet the health needs of the community. All of them are involved and play their respective roles to provide quality water and its management. Roles of different agencies are listed below: â⬠¢ Ministry of Water Resources: The Central Ground Water Board is monitoring both quantitative and qualitative data with regard to ground water. Apart from this CGWB has developed ground water maps concerning various qualitative issues. â⬠¢ Ministry of Urban Development and Poverty Alleviation: Working through various Urban Bodies, the Ministry is involved in monitoring drinking water quality in the urban agglomerations. There are quite a few Water Boards especially in Metro Cities who are equipped to take up the job, but not all urban bodies keep watch of the quality of water being provided on regular basis. â⬠¢ Ministry of Rural Development: Department of Drinking Water in the Ministry is working through State public Health Engineering Departments or Water oards are monitoring the drinking water quality in the rural areas of the country. Almost all the districts do have WQ laboratory. Though WQ is generally tested during installation, follow up testing is not done on regular basis. The department in certain places is initiating community involvement for WQ testing including ââ¬Å"Catchments Approachâ⬠. â⬠¢ Ministry of Environment and Forests: Working through Central Pollution Control Board, the Ministry is involved in monitoring water quality of main rivers and big water bodies. Most of these water sources are being used for drinking water purposes. So CPCB itself or through State Pollution Control Boards is having a watch on raw water quality. â⬠¢ Ministry of Health: So far the Ministry had been playing a limited role with regard to drinking water surveillance in some selected areas. But with the inclusion of drinking water under food category, MoH will be playing a significant role. Also Indian government enforced National water policy in 2002 and water pollution act( prevention and control) 1975 for maintaining water quantity and quality. CONCLUSIONS It takes the cooperation and the education of everyone to help clean up our biggest drinking water threats. The more environmentally friendly everyone becomes, the closer we get to finding cleaner drinking water and protecting our natural environment. Industrial and personal responsibility for our environment is the first and most significant step toward clean drinking water in the country in every community. According to a 2007 World Health Organization report, 1. 1 billion people lack access to an improved drinking water supply, 88% of the 4 billion annual cases of diarrhea disease are attributed to unsafe water and inadequate sanitation and hygiene, and 1. million people die from diarrheal diseases each year. The WHO estimates that 94% of these diarrheal cases are preventable through modifications to the environment, including access to safe water. Simple techniques for treating water at home, such as chlorination, filters, and solar disinfection, and storing it in safe containers could save a huge number of lives each year. Reducing deaths from waterborne diseases is a major public hea lth goal in developing countries.
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