water conservation a global concernDocument Transcript
2ndInternational Conference on Emerging Trends in Engineering & Technology, April12-13, 2013College of Engineering, Teerthanker Mahaveer University.1WATER CONSERVATION: A GLOBAL CONCERNPriyank Gupta1, Mohd. Danish1, Javed Alam2, Mohd. Muzammil3Water is a basic necessity for life on the globe. It is used for many purposes in one way or other such as for drinking,irrigation, recreation, and generation of electricity, industrial and commercial purposes etc. Its careless use hasresulted in the depletion of its good quality and also quantity. The total volume of water on Earth is about 1.4 billionkm3. The volume of freshwater resources is around 35 million km3. Out of these fresh water resources, about 24million km3is in the form of ice and permanent snow cover in mountainous regions. Around 30% of the world’sfreshwater are stored underground in the form of groundwater. This constitutes about 97% of all the freshwater thatis potentially available for human use. Freshwater lakes and rivers contain an estimated 0.3% of the world’s freshwater. The Earth’s atmosphere contains approximately 13,000 km3of water. The total freshwater supply forecosystem and humans is about 200,000 km3of water which is less than 1% of all freshwater resources. Amongvarious continents, Asia has the worse position with 36% of the available fresh water reserves, with over 60% of theworld population where water is a scarce commodity. As the population is increasing at an exponential rate andfresh water reserves are depleting so this resource need to be conserved for our future generations. This paperpresents various ways and means of water conservation adopted in various countries so far with a focus on India.Keywords: Water Conservation, Rainwater Harvesting, Grey Water, Water Resource1. IntroductionIn most regions of Asia and the Pacific, wateravailability has rapidly decreased. While Asia has theworld’s highest rate of increase of water withdrawal,water availability per capita ranks as least in the world4,200m3/capita per year. In 2025, water availability percapita in the region will be between 15 and 35 percentless than that of 1950  as shown in Fig. 1. In SouthAsia, which has the lowest level of water resources percapita, water availability per capita has alreadydecreased by almost 70 percent since 1950. Other subregions have also experienced drops in wateravailability per capita, with North Asia having lost 60percent and Southeast Asia 55 percent since 1950. It iswell-known that Iran and Afghanistan suffer chronicwater shortages. The Pacific countries also experiencewater shortages despite good rainfall because of thelack of appropriate investment and technology for waterstorage. At the same time, more than half of thepopulation in the region lacks access to adequate1. M.Tech. Students, Zakir Hussain College of Engineering &Technology, Aligarh Muslim University, Aligarh, India.Email:firstname.lastname@example.org,Email:email@example.com. Associate Prof., Department of Civil Engineering, ZakirHussain College of Engineering & Technology, AligarhMuslim University, Aligarh, India. E-mail:firstname.lastname@example.org. Prof. , Department of Civil Engineering, Zakir HussainCollege of Engineering & Technology, Aligarh MuslimUniversity, Aligarh, India. E-mail: email@example.com systems Water scarcity impacts, foodavailability, human health, livelihoods and alsoeconomic development. It is said that the poor are themost vulnerable to the impact of this water crisis. For aregion which is home to about 60 percent of world’spopulation and about 70 percent of the world’s poor, theconservation and environmentally-sound, use offreshwater resources is the crucial element for socio-economic development and poverty alleviation.Reflecting the importance of sound water managementin the promotion of sustainable development in theregion, recent international and regional conferenceshighlight freshwater issues as a priority area forachieving sustainable development.MinisterialFig.1 Decline in Water Resource Per Capita (1950-2025)
2ndInternational Conference on Emerging Trends in Engineering & Technology, April12-13, 2013College of Engineering, Teerthanker Mahaveer University.2Conference on Environment and Development in Asiaand the Pacific (MCED) in 2000 identified conservationand integrated management of freshwater resources asone of the eight priority areas for the region. The High-level Regional Meeting for the World Summit onSustainable Development held in Phnom Penh inNovember 2001 also paid special attention to freshwaterresource management as one of the key issues forsustainable development in the region. The MinisterialDeclaration issued at the International Conference onFreshwater held at Bonn in December 2001 also made acall to the Secretary General of the UN to strengthen thecoordination and coherence of activities within the UNsystem on water issues in an inclusive manner. How canthe needs of the increasing population of Asia and thePacific are fully met without sacrificing thesustainability of the region’s finite and vulnerablefreshwater resource.In the Asia-Pacific region where about 70 percent of theworld’s poor live, the needs of the poor should beprimarily reflected in water development andmanagement policies. The region’s water policy shouldbe linked closely with poverty alleviation policy.2. Global Water AvailableThe total volume of water on Earth is about 1.4 billionkm3. The volume of freshwater resources is around 35million km3, or about 2.5% of the total volume. Out ofthese fresh water resources, about 24 million km3or70% is in the form of ice and permanent snow cover inmountainous regions, the Antarctica and Arctic regions.Around 30% of the world’s freshwater is storedunderground in the form of groundwater. Thisconstitutes about 97% of all the freshwater that ispotentially available for human use. Freshwater lakesand rivers contain an estimated 105000 km3or around0.3% of the world’s fresh water. The Earth’satmosphere contains approximately 13,000 km3ofwater. The total freshwater supply for ecosystem andhumans is about 200,000 km3of water which is lessthan 1% of all freshwater resources .Among various continents, Asia has 36% of theavailable fresh water reserves, with over 60% of theworld population where water is a scarce commodity. Infact compared to Asia, Africa is in a better situation,where 13% of the population has access to 11 % of thefresh water reserves. Australia have plenty of water with1 % population owning 5% of the fresh water reserves,followed by North and Central America, with 8%population and 15% water reserves and South Americawith 6% global population and 26% fresh waterreserves. Since generations, the pattern of water use indifferent countries is mostly dependent on their culture,lifestyle and industrial development, as availability ofwater was not a serious concern .3. WATER RESOURCES IN INDIAIndia receives a fair amount of rainfall well distributedover 5-6 months in the year. The average annual rainfallin the country is 1170 mm with a wide range between100 mm in desert areas of Rajasthan to 10000 mm inCherapunji. The total available sweet water in thecountry is 4000 billion m3per annum. Out of this, over1047 billion m3water is lost due to evaporation,transpiration and runoff, reducing the available water to1953 billion m3and the usable water to 1123 billion m3.It is disturbing to note that only 18% of the rainwater isused effectively while 48% enters the river and most ofwhich reaches the ocean. Out of the total usable water,728 billion m3is contributed from surface water and395 billion m3is contributed by replenish able groundwater. Against the above supply, the water consumedduring the year 2006 in India was 829 billion m3whichis likely to increase to 1093 billion m3 in 2025 and 1047billion m3 in 2050, as estimated by the Government ofIndia (2009).Table 1. Per Capita Water Availability in India(source: Government of India 2009)YearPopulation(million)Per CapitaWateravailability(m3/year)1951 361 51771955 395 47321991 846 22092001 1027 18202025 1394 13412050 1640 11404. Need For Water ConservationDue to the changing scenario and various initiativestaken by Government of India and other countriespeople now came to know the importance of water andconcern about the fresh water resources. As we knowthe population is increasing at an exponential rate andfresh water reserves are depleting by the same rate sothis resource need to be conserved for our future
2ndInternational Conference on Emerging Trends in Engineering & Technology, April12-13, 2013College of Engineering, Teerthanker Mahaveer University.3generations. As can be seen in above table, the percapita water availability in 1951 was 5177 m3per yearwhen the total population was only 361 million. In2001, as the population increased to 1027 million, theper capita water availability reduced drastically to 1820m3per year. By 2025, the per capita water availabilitywill further dropdown to 1341 m3and to 1140 m3in2050. As the water available within the country varieswidely as a result of rainfall, ground water reserve andproximity to river basins, most of the Indian States willhave reached the water stress condition by 2020 andwater scarcity condition by 2025. This paper is relatedto various methods available for its conservation andproper use.5. Methods For Water ConservationThere are several methods available for waterconservation, some of which are -5.1. Grey Water ReuseIt is water generated from bathroom sinks, showers, andwashing machines. It is not water that has come intocontact with faeces, toilet. Grey water may containtraces of dirt, food, grease, hair, and certain householdcleaning products. While grey water may appear“dirty,” it is a safe and can be used as source ofirrigation water in a yard (as shown in fig. 2). If releasedinto rivers, lakes, or estuaries, the nutrients in greywater become pollutants, but to plants, they are valuablefertilizer. Not only it helps in saving water and reusingit, keeps it out of the sewer or septic system, so it helpsin reducing the chance that it will pollute local waterbodies. We can easily use grey water by connecting itthrough pipe directly outside and use it to water ourplants or fruit trees. Grey water can be used directly onvegetables as long as it doesnt touch edible parts of theplants. In any grey water system, it is advised not to usewater which contains bleach, dye, bath salts, cleanser,shampoo with unpronounceable ingredients, and noproducts containing boron, which is toxic to plants. It iscrucial to use all biodegradable soaps whose ingredientsdo not harm plants. Most of the powdered detergent,and a few liquid detergent, is sodium based, which cankeep seeds from sprouting and destroy the structure ofclay soils so we have to choose salt-free liquid soaps.While using these products, we have to make sure thatthese products must not contain substances toxic tohumans, including parabens, stearalkonium chloride,phenoxyethanol, polyethelene glycol (PEG), andsynthetic fragrances.Fig. 2 Grey Water Reuse Experimental Setup5.1.1.Basic Grey water GuidelinesThere are certain guidelines to use grey water which aredifferent from fresh water and are as follows-Never store grey water (more than 24 hours)because the nutrients in it will start to breakdown, creating bad odours.Water discharge system should be designed insuch a way that grey water containingpathogens (human faeces) should be allowed toget soaked separately and should not beavailable for drinking purpose for animals andhumans.Do not allow pooling of grey water as it is thebreeding place for moquitoes which can lead toseveral diseases.Our grey water system should be as simple aspossible because simple systems last longer,require less maintenance, require less energyand cost less money.Septic water should be discharged separately.
2ndInternational Conference on Emerging Trends in Engineering & Technology, April12-13, 2013College of Engineering, Teerthanker Mahaveer University.45.1.2. Types of Simple SystemsFrom the Washing Machine –Washingmachines are a very good source of grey wateras each washing machine has an internal pumpthat automatically pumps out the water whichcan be connected directly to water our plants.From the Shower-Showers are a great source ofgrey water they usually produce a lot ofrelatively clean water. To have a simple,effective shower system we require a gravity-based system (no pump). If our yard is locateduphill from the house, then we require apumped system.If the volume of grey water produced is more than weneed for irrigation, a constructed wetland can beincorporated into your system to "ecologically dispose"of some of the grey water. Wetlands absorb nutrientsand filter particles from grey water, enabling it to bestored or sent through a properly designed dripirrigation system (a sand filter and pump will also beneeded- this costs more money) .5.2. Rainwater harvestingRainwater harvesting is an effective way to deal withwater crisis as it provides a method to store rainwaterfrom households, factories, schools and offices toovercome their problems of irregular and inadequatewater supply or water supply of poor quality. Thisprocess involves storing rainwater that falls within one’spremises and re-using it after basic treatment. There arecertain simple instruments which are easily available todivert the rainwater towards existing underground tanksor terrace fitted tanks and then supplied to the taps. Thiswater is then treated by using certain purificationtechniques and this treated rainwater is safe not just forcleaning and washing but also for cooking and personalconsumption.We know that water is very precious resource for thesurvival of humans, animals, plants etc. A large amountof water goes waste into gutters during monsoon season.We can collect the rain water into the tanks and preventit from flowing into drains and being wasted. It ispracticed on the large scale in the metropolitan cities.Rain water harvesting comprises of storage of water andwater recharging through the technical process. In thelong run, rainwater harvesting will replenish the India’srapidly depleting ground water levels, and lead to watersecurity and sustainability.5.2.1. Methods of Rainwater HarvestingBroadly there are two ways of harvesting rainwaterSurface runoff harvestingRoof top rainwater harvesting5.2.2.Surface Runoff HarvestingIn urban area rainwater flows away as surface runoff.This runoff could be caught and used for rechargingaquifers by adopting appropriate methods.5.2.3.Roof top rainwater harvesting (RTRWH)In rooftop harvesting, the roof becomes the catchments(as shown in fig. 3), and the rainwater is collected fromthe roof of the building. It can either be stored in a tankor diverted to artificial recharge system. This method isless expensive and very effective and if implementedproperly helps in maintaining the ground water level ofthe area.Fig. 3 Roof top rainwater harvesting (source:MPPCB)5.2.4.Methods of Roof Top Rainwater Harvesting188.8.131.52. Storage of Direct useIn this method rain water collected from the roof of thebuilding is diverted to a storage tank. The storage tankhas to be designed according to the water requirements,rainfall and catchment availability. Each drainpipeshould have mesh filter at mouth and first flush devicefollowed by filtration system before connecting to thestorage tank. It is advisable that each tank should haveexcess water over flow system. Excess water could bediverted to recharge system. Water from storage tankcan be used for secondary purposes such as washing andgardening etc. This is the most cost effective way ofrainwater harvesting. The main advantage of collectingand using the rainwater during rainy season is not onlyto save water from conventional sources, but also tosave energy incurred on transportation and distributionof water at the doorstep. This also conserves
2ndInternational Conference on Emerging Trends in Engineering & Technology, April12-13, 2013College of Engineering, Teerthanker Mahaveer University.5groundwater, if it is being extracted to meet the demandwhen rains are on.184.108.40.206. Recharging ground water aquifersGround water aquifers can be recharged by variouskinds of structures to ensure percolation of rainwater inthe ground instead of draining away from the surface.Commonly used recharging methods are:Recharging of bore wellsRecharging of dug wellsRecharge pitsRecharge TrenchesSoak ways or Recharge ShaftsPercolation TanksRecharging from Roads5.2.5.Benefits of Rainwater HarvestingRainwater harvesting is one of the best methodsavailable for water conservation first of all it increaseswater security as it meets the water demands during lowdischarge periods especially during summer and it alsohelps to meet water requirements especially in the areaswhich do not have sufficient water resources. It helps inimproving the quality of the ground water andincreasing the ground water level. It reduces the loss oftop layer of the soil. If we capture the water directly weneed not to depend much on the water storage dams. Itis the good solution to the increasing water crises. Rainwater harvesting reduces the flooding on roads andfurther prevents it from contamination.6. Simple Ways for Water ConservationThere are many effective ways to conserve water in andaround your home, apartment, villa, office etc.Following are simple ways for water conservation .When washing dishes by hand, don’t let thewater run while rinsing. Fill one sink with washwater and the other with rinse water.Run your clothes washer and dishwasher onlywhen they are full. You can save up to 1,000gallons a month.Install covers on pools and spas and check forleaks around your pumps.Monitor your water bill for unusually high use.Your bill and water meter are tools that can helpyou discover leaks.Encourage your family to keep looking for newways to conserve water in and around yourhome.Housing Society or Apartment ownersassociation must adopt rainwater harvesting.Turning the water off while you lather the soapcan save as many as 5 gallons of water eachtime you wash. Use one glass of water forbrushing teeth instead of running the tap.Use dual piping one pipe for drinking, bathingand utensil cleaning where other pipe will bringin rain water and treated water for toilet, lawnsetc.Shorten your shower by a minute or two andyou’ll save up to 150 gallons per month.Teach your children to turn off faucets tightlyafter each use.A water leak detector or water leak detectionsystem can alert you of any possible plumbingmalfunctions in your home or apartment. Evena small leakage can cause huge water losses.Wash your vehicle with bucket of water andsponge than using a hose.Toilet is one of the source wastes waterunnecessarily. Upgrade your toilet with newwater efficient models.A trained property manager can manage watersystems such as saving water in swimmingpool, proper management of waste water,detection of leakage etc.The practice of installing individual watermeters on multi-family apartment units andbilling based on actual consumption results inwater savings 8,000 gallons per year.Everyday water is wasted, while bathing andother activities, therefore all new buildingsshould implement the systems to collect andrecycle used water.One must check usage by maids and domesticservants, since it is these people who are theend users of the resource in apartments, villa,office etc.7. ConclusionFor India’s future generations to be ensured of a reliablewater supply, sustainable management practices must beimplemented to preserve the nation’s dwindlinggroundwater resources. For more than one billionpeople of India, though hidden from the naked eye,groundwater depletion is a real and serious issuedeserving of political and humanitarian attention. Thepresent study reviews and suggests the concept of usinggreywater and rainwater harvesting in various possiblefields and thus, making fresh water demand withincontrol. The use of these methods is in their initial stagein India. Though, various developed countries are
2ndInternational Conference on Emerging Trends in Engineering & Technology, April12-13, 2013College of Engineering, Teerthanker Mahaveer University.6already utilizing these new water potential after somepreliminary treatments depending upon the type of use.References Asian Development Bank, “Water for All: TheWater Policy of the Asian Development Bank” United Nations Environment Programme (UNEP). Hegde N. “Water scarcity and security in India”,BAIF-Indian Science Congress, 2012. greywateraction.org/content/about-greywater-reuse. http://www.mppcb.nic.in/RWH.htm http://www.commonfloor.com/guide/20-simple-ways-for-water-conservation-1857.html