 Now, the question is where do you dispose the industrial non hazardous waste? Somebody was talking about disposal of radioactive waste in ocean completely do not talk about this at all. The first is land disposal just throw it on the ground and forget about it which most of us are doing. Ocean disposal well there was a situation where this was being adopted. A better way would be encapsulate the waste in a matrix of concrete and those concrete units can be dispose of in some water body, but this also has been stopped particularly because of lot of environmentalists and the people who are more concerned about the aquatic life. Most of the projects where reclamation is involved they all go through litigation why you are disturbing the complete ecology and synergy of that locality. So, there is a very strong group of people who is against this type of development in the country incineration that is you reduce the weight of the waste volume of the waste another problem is you generate lot of ash. See what disposal is becoming a very big issue? What is the difference between Poway lake and Vihar lake? Well 20 percent of your answer is correct, but you are not sure that which side it is correct. What I understand and what I know is that Poway lake is a non drinkable water is a non portable water while Vihar lake water is being used for supply of water to the entire city. So, yes your guess is correct that is what I said 20 percent you are right. Oxidation ponds are particularly whenever you fly over whenever you are landing in Bombay, then you can see next time when you come to Vashi creek and then you start looking down you can see the aeration ponds or the lagoons at Mulun, Bandhup, Ghatkopar. They are the good example of aeration ponds for the entire city. Before disposing the sludge in the sea they are treating it there and then slowly and slowly they discharge the sludge into the sea lagoons we are talking about these are the same lagoons surface impoundments. So, this also becoming a very big issue in geotechnical engineering how to design lagoons you know. What are lagoons? Just now I give an example. Oxidation ponds are sort of a lagoons are nothing, but a structure is a open structure having some sort of an impoundment or attainment. So, you make a small small embankments so that water can be stored. So, a salt pan lagoon is the one where salt is being produced. If you are using this land for aeration of sludge it becomes aeration lagoon or surface impoundments. So, wherever you are impounding the sludge on the surface construction applications debris and so on. And then ultimately the resource recovery becomes a very important issue. How would you recover the precious metals or the material out of it? Sometime back there was a philosophy that radioactive waste can be stored in a space. So, some countries tried that also. You contain the entire waste in a satellite in a rocket and just show it up. So, lot of people have tried that in fact, but now there is a international agency which monitors the activities associated with atomic energy and its regulation all over the world which is known as IAEA international atomic energy agency. So, all the countries have to comply with the norms and the regulations which have been created by them. And if you do not comply you know what happens. Any examples which comes to your mind? Iraq war, NPTs the issues are you know at a very different level. If you do not comply this is what is going to happen. And let us talk about hazardous waste as per the US EPA that is United States Environmental Protection Agency. Their website is www.epa.gov. So, which classifies most of the industrial activities as the main source of generation of hazardous waste. And this type of waste poses significant threat to the environment and health in combination with other materials or alone. So, as per EPA what is EPA environmental protection agency. And in 1980 they came up with four classification schemes. The type one is aqueous inorganic type two is aqueous organic type 3 is organic and type 4 is hazardous sludge slurries and solids. So, this is a classification scheme which has been used for defining hazardous waste. Aqueous word is more important because otherwise it will be in a passive form. So, if you remove this aqueous form then this waste has to interact with water to become active. But organic substance does not require any liquid phase this cell will be quite active. And most of the sludges slurries and the solids which are contained in these sludges are classified in type 4. So, which one will be more you know intensive type 1 or type 4. The order of activity should be increasing from 1 to 4 or it should be decreasing from 1 to 4 does not matter what is your guess. Increasing order well I have no idea. So, aqueous inorganic substance would be passive or active just read EPA in 1980 and then find out. So, this is assignment for all of you. So, as we understood by this time that most of the hazardous waste are coming out of the industrial activity. They pose significant threat to the environment health in combination with other materials or alone. Now, what is the meaning of this hazard? This hazard is associated with waste is not only due to its presence, but also due to its concentration. So, hazardous material in a very dilute form may be harmless even though in its concentrated form it may be very toxic. So, this is a relationship between toxic and hazardous behavior or toxicity and hazardousity. As such detection of a hazardous material in the ground does not necessarily indicate a significant problem. So, most of time people are unnecessarily worried. So, this is a catch that in a very dilute form it may be harmless even though in its concentrated form it may be very toxic. So, that is why the best policy of disposal of waste is dilution, but you have to be very careful from where you are going to bring water. Water itself is becoming a very big scarcity is it not. So, there is no water available now and your generations definitely will face this. So, never underestimate water now. So, this is a very big problem. So, this is a recycling of water, rain water, harvesting and all those philosophies have you know come up. What are the sources of hazardous waste? The first is nuclear power plants. The second is municipal solid waste landfills, but remember we need more and more nuclear power nowadays is it not that is how the might of the nation is being decided. So, now we are in which group India G7, G9 or what we have joined a league of groups you know league of nations and on what basis check it out G11 just check out. So, this is where actually the whole country is now you know on a cross road. We experiment a lot with thermal power there was a time when everybody was talking about hydral power, but hydral power posed lot of challenges it was very difficult there were so many dams which are constructed in the river valleys in the hilly terrains and all. Then people switched over to power plants thermal power plants you know the problems associated with every thermal power plant. They produce electricity definitely, but they produce lot of other things which are unwanted and the amount of land which is required. So, this is where actually lot of discussions were going on whether India should go totally thermal power based or nuclear power based. So, if you want to be called as a developed nation the ideal situation should be that there should not be any thermal power plant in the country the entire electricity and power should be generated from nuclear power plants and that is where your role becomes very important. So, this will do this reactor scientist will do that, but who is going to tackle the byproduct that is where most of the geotechnical engineers are required. The second situation is municipal solid waste landfills, MSW landfills, chemical and primary metal industries. The Anklashwar in Gujarat is an example of how chemical industries have polluted the entire city and the entire region. Anklashwar is famous for most of the pharmaceutical companies. ONGC. ONGC earlier it was it was a hub of ONGC, but now it is known for some bad reasons and one of the reason says that the soil water is heavily polluted. Most of the chemical industries and pharmaceutical industries are located in Anklashwar. ONGC is in Mahesana by the way not Anklashwar. So, another culprit is paint and dye manufacturing industries. Zinc and lead tin which is integral part of the paint and dye. Anybody in the class from Jaipur or Rajasthan you might have heard sometime back that there was a ban on one industry which is very famous at in Jaipur. Jaipur was known for something marbles. Apart from that there was a Jaipur print you know they used to use a dye and they used to make those bed sheets particularly and because of this dye industry what happened to the water of the entire city. So, ultimately this was shifted out of Jaipur that and dye industry is dead no more because of dye manufacturing industries and the you know subsidiary units associated with this process of dyeing. Most of the mining industries they are associated with the hazardous waste we were talking about acid mines. So, that again is hazardous could be toxic also, but you think of the situation where most of the minerals have been taken out and heavy metals leached from them. So, this is where the mining industries and of course, milling milling milling tailings and the mineral tailings are also attributing a lot to this problem. Paper and pulp industries we have talked about what are the issues associated with paper and pulp. Badrachalam area is famous for this and in North India Roorkee that place Nipanagar and Roorkee area is quite famous for this. Another culprit is battery and fuel cell industry. So, present day society is now migrating from electricity to batteries. So, what is the component associated with battery manufacturing which is highly toxic and hazardous? What is the name of the batteries which you use in most of your electronic devices? Nickel. Nickel cadmium. Nickel cadmium. Nickel cadmium is the biggest culprit and electronic circuits zinc mercury. So, battery and fuel cell industry. So, they cause too much of hazardousity to the environment. Leather industry Kanpur is famous for this and in South India Mysore lot of tenon is produced out of this which was being disposed of in the river in the free water bodies. Electroplating is another example of the hazardous waste generation or the source of hazardous waste generation. Lot of assets are employed in electroplating process and lot of heavy metals you know are thrown directly into the form of the spent fuels, spent electrolytes. It can be a good research topic particularly those of you are interested like whenever you do electroplating what is that you utilize? Say suppose if you are doing silver or iron sorry silver or let us say gold electroplating. So, from the solution you are recovering all silver ions and gold ions and what is remaining in the solution in the form of spent ions is chlorides or where you are going to throw them. So, truly speaking the entire area becomes heavily contaminated chlorides and textile industries which is supposed to be quite hazardous waste because they use heavily either the cleaning process, starch and you know coloring process. So, these are the sources of the hazardous waste and last, but not the least which is becoming very significant nowadays is hospitals and pharmaceutical companies. See the requirement of presented society is that everybody wants to live close to the hospitals is it not and without realizing that what if the consequences are having hospitals next to your door. So, this is becoming a big challenge the hospital waste which could be of bio in nature bio waste how to tackle it and most of the pharmaceutical companies the type of waste which they are producing. So, some of the examples are heavy metal and the non biodegradable synthetic organics you need not to remember all this just for your general knowledge like lead is dioxin mercury is in DDT arsenic capon cadmium mirex these are all compounds tin PCB boards zinc is in carbon tetrachloride chromium benzene copper chloroform beryllium strontium PBC. So, I do not know whether you might have read this or not people were debating whether to use a certain what you say certain brand of shoes and chapels. Did you hear this case from 7, 8, 10 years back it was in very hot debate that the rubber souls leech out lot of they are made up of PBCs is it not. So, they will leech out beryllium strontium which are not good for skill a few years back there was a case where there was a ban on toys from certain country. So, why because in most of the polymers you have these heavy metals and which gets have a tendency to chew or to come in contact with directly. So, that is why there was a ban. So, everywhere they use the word leaching I mean anything which gets dissociated very easily from the waste form and it is free to get consumed either directly or indirectly all right. So, this I thought I will give you an example of NTPC corba. This is the power plant from a distance this is a railway line when you go to corba you will be passing through this you will find lot of mountains over here now which geological formation is this you are from nearby area and you are a geologist by profession sorry coal any other guess. So, let me give you a hint let me ask you a question whether this is manmade or this is natural this is manmade which looks like a hill ok. This is the over burden which has been dumped and lot of hills have been created in this region near Raipur corba and all that belt western coal fields are there all right. So, the more you dig out coal the more these type of mountains are going to be created this is a pure human activity from a near distance looks like this. So, these are the mounds of the over burden over burden is nothing, but the top soil which has to be removed before you dig the coal from the mines and it may range from 2 meters to 3 meters to 4 meters depending upon your luck and depending upon the circumstances. So, in order to get certain amount of coal you have to remove that top soil and that volume could be of this magnitude. So, these guys approach this and basically these are coal moisture residues look at this. So, whatever coal cannot be used in any form has to be stacked like this. So, there was a question that can we use this material for some good applications we did this project. So, this is open cast mine all right where they keep on removing the coal from the ground. There is another view of the mine you can see this much of the soil or the coal has already been removed and then this is how you keep on going deep up to almost 7 8 meters. During rains the water gets accumulated here and becomes a ideal candidate for acid mine drainage. So, the entire area has a big water scarcity first of all and second thing is whatever water is present is all contaminated with sulfuric acid and what not. Those who are staying here they are having a very tough time. So, the immediate application of this residues was to railways wanted to have siding and railway you know platforms for carrying the coal from the mines and then dumping it. So, this is one piece of the land this is one piece of the land and the there was a valley in between and this depth was almost 20 meters. It does not look like I did not take a good photograph somehow, but it is almost more than a kilometer long and 20 meter deep maximum. So, this is another view of how coal is being taken out from the mines and on the side you can see the coal residues which are of no use and they require some immediate. Now, this is the scenario. So, this is one of the mounds on which we are standing and you can see the ground how deep it is and there is a road in fact, on this mound which has been done. So, this is the another view of the coal residues this is from one mine remember there are may be at least 50 60 mines which are legal mines are about 50 60. So, this height would be about 40 meters this is how the contractor makes the roads. So, that the further level of dumping can be done and the mounds are increasing day by day. So, now, you can put your geotechnical engineering concepts earthquake rainfall instability. So, all it is a very good place to study geotechnical engineering. So, rains take place the water goes into the partially coal residues it leaches out and so on all it. So, this is another this is Dr. Naidu is standing here he had gone along with me and you can see the entire area these are the mounds you can see in the background of the coal residues ok. So, they are quite high in height about 40 50 meters these are manmade mountains is another view of the portion where you can very easily approachable with the help of a car. So, this is how 6 to 10 million tons of the coal residues was used for making one embankment and height of the embankment was almost 16 meter 20 meter depending upon the different changes. This is the topography of the side you have R L in terms of the ground level and in terms of the formation of the level. So, then what we did is we buried this coal residues used lot of native soil and made a carriage way for railways. So, these are the wheel load and this is where the entire stability analysis was done the idea was to maximize the application of coal residues. So, this becomes a very interesting problem, but the issue is that you will appreciate you will not get much native soil there because that land land is famous for giving coal not the soil. So, it is very difficult and you want to reduce the thickness of the top cover. So, then keep on reducing the cover of the native soil maximize the volume of the coal residues and then keep on doing the stability analysis. So, this was the ultimate design which was subject which was given to them. The height of the embankment you can see is about 16 meter and the width is about 45 meters. So, huge construction and, but now if you look at the from the other angle coal residues are going to be active material. So, we say it is a biodegradable material is it not. So, how you are going to make this system remain stable over a period of time. So, that this should not get disintegrated, otherwise you will find lot of corrugations and distresses on the surface. So, there was some treatment which was given to this coal by sprinkling basically lime solution or lime cement slurry cutting it off from the environment. So, that it does not get oxidized there is a very active system and this is how one job was completed. The challenge was to use the maximum amount of the coal residues I thought I will share this with you in the class ok. I hope you are appreciating now the applications of geotechnical engineering in the real life. These problems are mostly associated with the day to day practices of engineering. The irony of the situation is that power plant cannot be closed because it is a coal belt, but the more and more coal you extract from the ground you are dumping it on the surface and you are creating more and more manmade environment which is detrimental in the due course of time.