 So, what are the hazardous waste the source is USEPA I am sure you must be aware of what is USEPA United States Environmental Pollution Agency and if you go to the website you should go once and try to see what these guys are doing and you will get a lot of ideas you know what you as a citizen of a democratic country can do major sources industrial activity and hazardous waste poses a significant problem and threat to the environment and health of the Pono and Flora in combination with other materials or alone. These are the four categories of the hazardous waste which normally we talk about and this is as per EPA 1980 type 1, type 2, type 3, type 4, aqueous inorganic, aqueous organic, organic and then hazardous sludge is slurry than solids. So, these are the very wide criteria which has been used to classify the hazardous waste. Now, I am sure from my discussion until now you must have realized that hazardous waste is posing a big challenge and hazardicity comes because of the attributes which we have discussed today, is it not? So, pathogenic activity, radioactivity, inflammability, you know explosive nature, it could be irritant, it could be getting decomposed easily, it could be non decomposable, it could be having odor in it, it could be infectious. So, all these things are adjectives right now, are you getting this point, infectious. Now, somebody asked me a question, how infectious the material is, is there scale from 0 to 10? Like in your soil classification system, you have numbers, Cu, C, C, PL, L, L, you know, PI, shrinkage limit and all, so all this has been quantified, but I am sure there must have been a time where everything would have been a philosophy and then people started working on this and they generated a lot of data and then they showed that bring a soil from anywhere in the world, it follows these indices, it follows these norms, rules. So, I hope I have conveyed the message to you that most of these things are still in the descriptive form, they do not have number assigned to them, so where the research has to be done is to quantify these effects, so if somebody says explosivity of the material, what is the explosion index, which has to do with the chemistry of the material, composition of the material and so on, environmental conditions, what pressure, what temperature, what wind velocity, you know, this might happen. So, hazardous waste is the one which is having major sources of industrial activity and this poses significant help or hazard associated with the environment, there is something known as the concept of the concentration, so hazard associated with the waste is not only due to its presence but also due to its concentration and this is where we talk about a term which is known as, you know, hazardicity and toxicity, when concentration of the contaminants in a system go beyond permissible limits, they become toxic and as long as they remain within the permissible limits, they are hazardous, so given a chance which one you will prefer, hazardicity or toxicity or which one you will think of negotiating with, I will prefer hazardicity because toxicity is something which has gone beyond a certain numbers, certain limits, the question is who sets these limits, pollution control boards, clear or the agencies which are doing statistical analysis, so if these type of industries are running in this area and this type of sludge is being disposed of what type of diseases prevail in the nearby, you know, township, clear and then if I make a model out of this, sometimes when you get chance please check on net biodiversity analysis, so there was a time when geotechnical mean has never talked about these terms, I hope you can realize bio is something which geotechnical mean has never bothered about and diversity also we never bothered about but I am sure now these are the terms which are becoming contemporary in our practice of the subject. So biodiversity talks about what I discussed just now, there is an industrial activity and I would like to know what is the influence of this industrial activity in the surroundings and these surroundings could be x, y, z, t, you remember, long, long back we discussed all these things. So this is where based on the statistical models and the agencies, environmental agencies, the numbers which they describe become guidelines or permissible limits and anything beyond that becomes toxic, unwanted and less than that is hazardicity. So this is what I have written here, hazardous material in a very dilute form may be harmless even though in its concentrated form it may become very toxic, most of the medicines is a good example, you know they are toxic, particularly you overdose but if you dilute them they are curative as well as hazardous also, so there might be some side effect but they might be curing your disease. So as such detection of a hazardous material in the ground does not necessarily indicate a significant problem, I can live with the hazardicity but not with toxicity. These are the very, very conceptual things but very abstract thinking, so as I said what you need to do is you have to quantify these statements, prepare guidelines, help pollution control boards, make society better, okay. So let me continue with this sources of hazardous waste, nuclear power plants, municipal solid waste landfills, chemical and primary metal industries, paint and dye manufacturing industries, mining industries, paper and pulp industries, most of the geotechnical engineers who are dealing with environmental geomechanics are very closely associated with these industries. Nuclear power plant I have discussed quite in details, MSW also I have given you some idea, chemical and primary metal industries. You can understand that ultimately a sludge is an issue, paint and dye manufacturing, read on internet that how these industries got affected because of the NGT order or maybe Supreme Court's order or High Court's order. So these are the topics in which the judiciary gets involved directly with the issues. Why? Because they are controlling the laws of the land. And one law of the land also is that behave in a manner that nobody else gets affected because of your activities. You ever wonder what paper and pulp industry is doing here in this list because paper and pulp industry produces lot of sludge. The more and more you wash the paper with acids and different chemicals you produce lot of sludge. And the sediments which come out of the paper and pulp industry are equivalent to the silt which is normally used in geotechnical engineering construction or for different infrastructure activities. I have discussed a lot about the mining industry also, alright. Similarly battery and fuel cell industry. So I am sure nickel cobalt, bismuth, cadmium, these are the heavy elements which are causing a big problem to the present day safeguarding of the geo-runment. As far as the gadgets are concerned, yes these are required and they are fulfilling the requirements. Leather industry, I am sure you must have come across that the leather is also a big issue. Particularly the type of leachates it produces and the contamination which it causes of the geo-runment. It is a big list, alright. Electroplating. So the more and more electroplating you do the spent fluid. The spent fluid is the one from which you have taken out the metals. So when you are doing electroplating and then the question is where to throw it, where to dispose it. It becomes a leaker of certain anions or cations when you do electroplating. So when you do electroplating basically cations go on to the electrodes, your bangles and all whatever you are trying to electroplate that will become a cathode on which cations will go and get deposited. So all anions remain in the solution and hence solution becomes a very concentrated anionic solution chloride anion that is said. So most of the industries are facing this problem that after the processing has been done the sludge which comes out of very high anionic concentration what to do with it and then they approach you to solve this problem. Are you realizing? So the concentrations would be 30,000 ppm, 50,000 ppm, extremely high concentrations. You are supposed to give a solution to these issues. It becomes interdisciplinary work now. Lather industry like in Kanpur, Tenerife are there. Sir is there any subsequent like significant improvement in their work right now after so many of since they are near the Ganga river that is why I am only asking about the Tenerife specifically. Correct. So you are quite knowledgeable, you are aware, you are aware of what is the situation. There is a central leather research institute also in the country. Let us go to the webpage and see what they are doing, where it is located, check it and visit their website and see what type of innovative things they are doing into the leather industry because leather brings lot of foreign revenues to a country apart from the revenues which local market also provides. Lather industries you must be aware of, there were so many judgments given by the courts on closure of the textile industry. Why? Jaipur is a good example, where the quota print used to be, you know dye printing used to be the main issue and it contaminates the ground water extremely. So there was a third, the way the leather industry was banned, similarly dyeing industry was also banned. But for a environmental geotechnologies this should not be a solution to a problem, banning is not a solution. What should have been done? Solution should have been provided, correct? So that nothing untoward happens to the geoenvironment. Now this is where the engineering is, you take a specific case and solve this problem and say this is the solution which I am giving to the society. Hospitals and pharmaceutical companies, I hope you can realize is a big challenge how to deal with the hospital waste, bio waste. The cancerous cells which are removed in the hospitals, who knows where to dispose and how incinerate them, correct? So these are the challenges pharmaceutical companies, the sludge which they are producing and which they are disposing. So these are good examples of hazardous waste. You can add on to this list, this list is never ending. Some of the examples of heavy metals I have written over here and how do they influence and what form they are obtained in different gadgets, utility items I have listed over here. So lead mercury, arsenic, cadmium, tins, zinc, chromium, copper, beryllium, strontium, these are the heavy metals which are checked or which are tested in drinking water and the sludge which are being disposed of. And on the right hand side I have shown, you know, what are the potential utility items where you might be having this. So somewhere you must have read few years back that the kids in India are not supposed to get exposed to the toys from a certain country, you came across these type of things very good. So you are aware of what is happening, so somebody must be forming these rules and regulations, is it not? Long long back there was a case against a company which used to make shoes. So imagine your bare foot is always in contact with the sole of the leather and if these soles are made up of PVC, what is going to happen as a scientist how would you analyze this problem, it is a contact mechanics problem. So you have a high chloride concentration in the PVC which is migrating into the blood vessels in your body. So non biodegradable synthetic organics, you know chlorinated hydrocarbons and in what form they are available I have written over here, lead is dioxins, mercury DDT, capone is arsenic, cadmium mirax, PCB boards which you have in your electronic gadgets, they have tin and it is leachable, zinc, carbon tetrachloride, benzene, chromium and different type of polyvinyl chlorides which might be having beryllium and strontium. So once you enter into this realm you have to understand that complete diagnostics of the soils where these type of manufacturing activities are being taken up has to be done, if they are contaminated you have to clean them up and if there is a potential of contamination you have to stop it alright and then this becomes a big issue for the nation and the society. Is the scope becoming clear that what are your activities and this is where you have to use advanced instrumentation tools to detect what the facts are ok. So moving on to a real life example some of you were very eager to know what is happening in the world and I will share my experiences with a project which I did long back at NTPC Corba, I am sure you must be aware of what is happening at Corba, NTPC is the main unit over there and they produce lot of electricity for the country. But when they produce electricity for the country at the same time they are producing lot of fly ash also and it is a big question that how to deal with this fly ash in a better way. Now what I am going to talk about here is not the fly ash but the coal which is used to run these 4 units of NTPC and I was involved by an Australian company here which were running the coal washel. So if you see from a distance this is the NTPC plant and lot of emissions are taking place in the environment and of course they may say that everything is safe because now they might have put back filters in the or the dust collection systems to clean up the emissions. I intentionally took this photograph I wanted to show you this is a railway bridge through which a railway you know wagons are moving, the train is moving and in the background if you see that there is a big hill which have been created by human activities and these hills are several in numbers in the Raipur Corba regions because these are the mining over burdens which we were discussing long time back. This could be the stack of the coal which is unused which is not of the good grade to get incinerated easily you know we were talking about the calorific value of the coal hardness of the coal alright. So if the coal is not of good quality there is no point in taking the industry because it cannot be incinerated it will not provide you proper energy. So one of the concerns is that the height of these hillocks which are manmade is increasing and we have discussed this in details. This is how they store the washery residues these are coal residues which have been stacked multi layer system and the mandate given to me was how to utilize these materials because unless you create a storage space the coal which is coming out of the open cast mining cannot be you know generated. So these are the residues from a closer picture you will realize that I am quite at a height or it must be about 35-40 meter high where these type of road system is created to bring the coal residues after washing and to stack them over here so this becomes a multi-tier system. This is a typical open cast mine this is one typical manmade mountain over burden which has been created at a quite distance from the mine and if you see from this point onward this is the ground and from here the cutting has started and this is the first seam of the coal and so on you have created ventures of the coal and this is how the coal is extracted it is a co-open cast mining. We are doing a project right now at Bhanegaon in Nagpur it is a very challenging project which I was discussing yesterday in the discussion that the more deeper you go the big issue is how to stabilize the slopes of the granular material which could be 40-50 meter high and unless you stabilize this mining operation cannot be done. There are several challenges so as I said long back it is not only the mining and engineers domain it is mostly geotechnical engineers domain and they give you all sorts of guidelines and we are trying to work on this problem. But from this the biggest issue is this being a sedimentary deposit and the river bodies of the surface water being very nearby this water discharges into the mines and hence it becomes very difficult to do the stability analysis of the cuts because of the excess seepage. There is another close look of how the benches have been created how the coal is being taken out and imagine what my intention was at one side you are doing mining you are going extra deep inside the ground on the other side you are creating mountains of overburden material both are hazardous but mining has to be done for the sustenance of the nation how long we will be bringing coal from other countries and you are losing a lot of foreign exchange. So incidentally what I have shown over here is that this is the agricultural land and then idea was to utilize the millions of tons of the coal residues to create some infrastructure. It is a good example of how coal residues get stacked at the coal washery unit washing of coal is a chemical process sometimes you have to wash it with acids sometimes you might have to treat it with different type of steam curing sometimes you have to give a treatment of different chemicals to get rid of impurities in the coal and so on. One thing you should realize is that today's geotechnical engineering is not mastering only one subject because then the problems become very very limited and scope of your activities becomes absolutely limited instead what society wants and looks up at you is they want a solution of the problem. So you have to learn in the process lot of subjects and their concepts so that you can give a good solution. So you have to learn lot of chemical processes why coal is a residue you know you have to ask these type of question when you go to the sites and meet people before you can solve the problem because ultimately the question is how to utilize this material which is of no use to the washery. So unless I have created a similarity between this material and the natural aggregates which are existing I cannot go ahead with the solution. This is how it looks is Dr. Nidu one of my PhD scholars who is a faculty now at IIT Chennai and the next one is Dr. Kohle who is now a faculty member at University of Carbondale close to Chicago. So these are the people who are associated with this project and this gives you a very clear idea about you know the washery somewhere here you are stacking the coal residue and this is the road which I was talking about to take the material to create a second plant of the storage. The huge areas like there will be in few acres of land and heights would be this level itself is about 20 meters and then each of the flights would be 10, 10, 15, 15 meters and so on. Imagine the magnitude of the problem this is one of the coal washeries in the country. I hope you can realize now the magnitude of the problem. Had it been a soil embankment I would not have bothered much about it but this is carbon material is it not. The chances of this material catching fire during summers are tremendous. Again formation is taking place because coal so flash point is there organic material and you are stacking it like this it is a hazard to store this material in your premises clear it could be inflammable and hope you can realize from the size of this car what is the height of the slope we were talking about. Now the question is what you are going to do with this material another beautiful picture of how do they manage the storage areas and how do they create further storage of the materials. You have to learn all these things management of the heaps of industrial by products and the waste material which is coming out. Another picture I wanted to show the manmade system like coal washery residues on which your Dr. Kole is standing. In the background you can see the manmade helox over burden when you remove the top soil and you stack it somewhere and look at the whole area this is a plain area near Korba but it looks like a very hilly terrain because most of these are made up by mining activities. I hope the statement of the problem is clear to you and the importance of the problem is clear to you. Now if geotechnical engineers cannot solve this problem who else will be solving this is a big question. Only thing is the material has got changed you have been doing slope stability analysis of silty traditional material C5 type of soils or sandy soils clear here the material has been changed the rest of the problem remains same there is another view. So this is just to tell you what the solution was. If you see this is the valley of the land you know this is the existing ground level and this is the formation level for the railway track which they wanted to construct. So in nutshell they just wanted to create a railway siding so that the operations become simple but soil is not available in the nearby area and what you have is the industrial byproduct and now the question is can I use this industrial byproduct which happens to be coal washery residue to create an embankment on which railways can fly. So if you re-analyze these results you will see that the height of the filling which was required to get this gradient of the formation for railways to fly was about 16 meters huge height clear. And in the process we consumed about 6 to 10 million tons of the residues is a substantial amount. So the rest of the things are simple I mean you do slope stability analysis but the question is from where you will get parameters you were discussing sometime back somebody asked what software is being used. So software could be the same but the question is now the soil has been replaced by the coal residues. So you have to perform all the tests on coal residues to get their fundamental properties unit weight density compaction, flakiness alright and then water absorption capacity, impact durability and so on alright you have done all these tests. Apart from all the series of the conventional test what you have to think about is ignitability it may it may get ignited because of fire migration of methane gas into it degradation of the material. Soils are less prone to degradation as compared to the organic matters like coal alright. So I am sure you must be realizing now the conventional subject has been topped with lot of interesting questions how would you model the material properties. Then substitute those properties and give a solution. So this is the first cross section which I tried to work on but what I realize is that if I have to cut off the coal residues which are encased over here I have to use lot of native soil and as I said native soil is not available because no villager is going to give you the soil for creating embankment they lose the land that too fertile land. So this did not work out. So what we did we kept on increasing the volume of the coal residues which can be packed in the embankment and reduce the cover of the native soil. But still you know people are greedy. So when they saw that this type of solution work they said why do not you increase the CR volumes and reduce the native soil further but I am sure now you will realize that this is a railway track. So most of the impact loading is going to come on the coal residues and they are fragile materials as compared to soil. So if there is no sufficient cover what is going to happen there will be impact induced degradation of the material you must have studied in your transportation engineering course. So you have to provide proper cushion so that the CR does not degrade because of the railway impact but there has to be a sufficient amount of native soil cover so that the free supply of oxygen to coal residues gets cut off otherwise what will happen they will degrade very fast and there is something known as you know methane formation because of the composition of the coal. So these are the challenges I hope you are realizing those are problem is very simple but when you have to start doing this from the point 0 it becomes challenging. So this I did in very early career and from here I learnt all these adjectives which I use now in my professional career degradability, durability, clear applicability of the material. So all these series started when we were working on this problem of course the client was very happy when I gave him this final solution that you can use so much volume of the material in the as an embankment followed by a very thin layer of the soil which is required to make a good embankment. So I hope you can realize that this is how the engineering can be done and when you are giving a solution what changes is the way of looking at the material. So similarly I remember I did another project near Valar Pradham in Kerala where I did lot of things. So my material got changed but I created a complete bypass for the entire Cochin city and this entire material came from the sea. Now this is the engineering and technology which cannot be taught in one day. So you have to sit down, you have to learn, analyze and then think of a solution.