 So, slowly and slowly what may happen suppose you have a stationary water table this plume which is coming out of the leachate in the form of the leachate from the landfill will settle over which I have shown like a mountain or a purple color you agree there is no movement of the water table. So, whatever leachates are coming out they form a stack. If I rotate this figure by 180 degree what is going to happen? This becomes a stack of a stack or a chimney and the chimney is throwing out all the pollutants in the atmosphere the problem remains same what has changed the media through which the transport is taking place agreed rest of the concepts are same. So, for me landfills are equivalent to a chimney or a stack through which a lot of unwanted materials are coming out of different attributes. So, the density of this system is going to be different their viscosity is going to be different because the temperatures are different density and viscosity are going to be a function of time their toxicity is going to be so much that this soil mass may not remain as what it used to be earlier. The chances are that the soil mass might get eaten up and hence the porosity the density and the attributes of the soil mass are also changing see these are height of complications. Now, this is a system where nothing remains constant I hope you are getting a feel of this is this ok and then the question is quantify this phenomena and give the answer is more realistic another question would be the whole process is going to be time dependent I hope you will appreciate this could be short lived it could be long lived there could be a process which might be occurring within few hours at the same time there might be few chemicals which might take their time to get activated over a period of time is this ok. And I was thinking like how will we proceed like we can forget about proceeding first thing is assimilation of an idea that these problems exist the first thing is to realize that yes there are issues in your mind and we should do something that itself is half journey done I am sure 99.9999 recurring populace of the country is not aware of what is happening including the geotechnical engineers which are being churned out from the institutions you agree. Sir can you please discuss the effect of Lechirle in the hard rock where you found a barrier there. Wait, wait, wait hold on everything will follow but as I said in the previous lecture rocks are very stable why? Combatness. So you really cannot disturb them so easily they are grandparents you keep on telling anything either they are deaf or dumb or they do not hear or they do not want they are not interested in anything clear passive materials mostly and hence beautiful depositories to deposit your waste good analogy ok particularly if it is a sound rock granite basalt this is what they try to investigate at what depth it is available in what form and these are the repositories repository is the word which is used to dispose high intensity atomic waste in the formations this is ok this is what you have been asking. So we are still talking about the most vulnerable species soils the offsprings clear it answers your question yes I know this takes time to understand what is happening yes anything. Sir the place where we dispose the byproducts also we can make impermeable chambers. Everything comes at a cost I have to see the repercussions of each and everything I have to evaluate each process I want everything in writing you write what you want then the analysis of that statement is this there are five situations which I will create out of this one situation would cost you this one will cost you this one will cost you this now you tell me what you want to do so with the moment the guide takes one now let us say we will start the engineering and for doing the engineering I have to diagnose again clear and once I am scientifically satisfied then I will go ahead with the execution I think this is what I have been describing about the spread of contaminants in the geo environment and remember geo environment is something beneath the ground beneath the ground surface constituting of soils, rocks, groundwater and the entire geo microbiosphere so geo microbiosphere so once I say that this is the sphere which is located beneath the ground everything comes in the picture flora fauna, geomaterials, soils, rocks, groundwater now suppose and I think I have answered your question for me that if what about the rocks if rocks are intact igneous in nature I need not to be bothered much and I am sure you will agree with me the more deeper I go I will find a place where the hard rocks which are intact are available nature has done great justice with us unfortunately we have been exploring only up to few meters from the surface and we say what to do go deep in anything you get the answer to your question so normally the waste disposal it as is at greater depths it could be kilometers deep also and whenever you get a chance please visit these are the repositories where beautiful laboratories have been developed hundreds of meter deep inside the ground homes like this where people observe everything and these are the guys who are running the whole country look at the second situation the second situation is the one where the stationary water table is moving now the situation is if I do not want to allow the spread of this contaminants you know contaminant transport up to infinite domain what I have to do suppose I have another industry of premises over here and because of my activities the contaminants might reach their premises because when they operate their tube wells when they withdraw water for drinking they will realize you know all these species are coming and if they analyze and they come to know that this is what you are producing in the nearby the MA file issued against you this is what is going on right now clear so you have to be very careful so what you want to do answer to your question I would like to confine this contain it so I can create a containment or a barrier by putting a sheet pile or by grouting the entire area clear those going to be expensive but this is the only solution nobody can negotiate with you and then you have the concepts of how to create barriers how to create you know deep grouts suppose the water table is moving now what is going to happen the entire plume is going to migrate so my question is which one is a better situation the first one which I showed where the water table is pregnant and the entire plume gets takes a form of a volcano or this one where the where the plume is moving from one place to another place so it is again a very dicey question so slowly and slowly what will happen if you have contained yourself also and the more and more leachers are filling the space in the geo bio micro biogeosphere what is going to happen now you cannot even use the water because every time you drill a bowl or a tube well what you are going to get whatever you have disposed there so not a very good situation you are sitting on a wall can be careful this you cannot afford why because the neighbors are going to complain so what should be done is a big question so I think now I have said the stage right for you to understand that most of these situations do not have clear cut answers did you ever feel this type of problem when you are solving a problem to compute bearing capacity of foundations you said well up to third decimal place the answer is 10.43 tons per meter square you are so confident now what is happening you are shaky why because even if you are writing something and reporting something you have to take care of all these unseen forces which are going to get affected by your statements so what we are supposed to do in this case we are supposed to find out the extent of migration of contaminant so most of the establishment when you visit like nuclear power plants or atomic power plants or thermal power plants you know there is a zone of influence they call it I do not know how many of you have visited such type of establishments when you start approaching them there is a warning zone no rehabilitation within this limit mostly atomic establishments have a limit of few tens of kilometers why answer comes from here so if I am dumping a waste over here if I have the waste disposal facility over here I am going to this analysis up to certain extent in distance domain and time domain you might have done these type of analysis where we call as time domain analysis and distance domain analysis clear so extent both in terms of time and space after 25 years how this activity is going to influence the settlements villages clear second thing is beyond 25 kilometer whether there is any influence of this activity or not both ways I can look at the second one is intensity of the activities and their concentration temperature chemical concentration radioactive concentration microbial concentration and so on now if you do this this is what EIA is because of my activities how I am influencing and how much I am influencing in how much time the geo and environment is a big question yes shall we adopt some ground improvement techniques so that they do not come into I wish life I wish life was so simple here you are not aware where the plumes are existing can you see through clear it is very difficult so then you have to evolve techniques which can detect the plume itself first imagine close your eyes and imagine you know when this type of plumes are getting formed then the 3d and what is the depth what is the extent xyz t so that part you have to imagine first yes if you can definitely go ahead with the remediation so first is diagnosis understand the problem diagnose it well third is start giving I will talk about that now this is what is the requirement you have to do modeling so when you do modeling you want to predict how the transport of contaminants is taking place and what is their fate whether they become more aggressive after certain time half life of an isotope you must have studied in your 10 plus 2 physics is it not so if the radioactive waste is there radio nucleates are there they might get fused they might show fission they might create daughter elements what those daughter elements are going to do what the parent element is going to do this is the fate of the system so a species of the contaminant how it is going to be in domain of xyz and t is a big question which and everybody is trying to work on and having done this I will ask you a question well very good you have done a lot of study a lot of analysis you have come out with the recommendation can you validate it and once you validate it I am ready to appoint you as a consultant I am ready to spend the money which you are asking for so both the things go together creation of hypothesis development of the mathematical models and followed by recommendations so this is where the importance of the following becomes very important first thing is you have to create a theory theory is because of this activity something is getting adversely affected how we should come out of the situation do the lapters what you are saying is I will take out samples bring them to the laboratory understand the material what type of soils are these sandy soil spread is going to be more clay soil spread is going to be less extend lateral stand extend vertical extend and so on I will do field test also to make sure that the type of data which I am getting from the laboratory is correct alright based on these two data lab and field I will create empirical relationships so most of the geomechanics relationship you must have seen are empirical in nature Cc equal to this this multiplied by LL minus 20 and so on clear what are those equations empirical relationships but they are better than having nothing in the hand then because the computer age you will like to put all the information in computer application artificial intelligence the whole of information technology and so on we will discuss about this later on and then ultimately what will happen having done all these models I would like to define a factor of safety I am giving a solution what is the guarantee the person is spending money how comfortable he or she could be at the end of the day so this is nothing but the factor of safety and what is factor of safety my judgment my experience of the past and how conveniently I can handle the situation is the factor of safety that is the application of the acquired knowledge and knowledge could be either based on your own experiences or by reading or by hearing whatever so I hope this concept is clear to you based on today's lecture that what environmental geomechanics guys are at this is part clear and what our activities and what we are supposed to do so once we have understood our role things become more streamlined we will discuss about this