[00:00:00] Bridget Scanlon: Welcome to the Water Resources Podcast. I am Bridget Scanlon. In this podcast, we discuss water challenges with leading experts, including topics on extreme climate events, over exploitation, and potential solutions towards more sustainable management. It's my pleasure to welcome Laurence Gill to the Water Resources Podcast.
Laurence, thank you so much for joining me today. Laurence is a professor in Environmental Engineering in the School of Engineering at Trinity College in Dublin. I attended Trinity College in the late seventies where I studied geology. We're both in the museum building. He went up one stairs and I went up the other side to geology.
So it's really fun to talk with you today about water issues in Ireland. Laurence, maybe you can give our listeners an idea of what type of issues you will be covering today and related to your research.
[00:00:58] Laurence Gill: Yeah, thanks Bridget. I describe myself as an environmental engineer, which I think kind of means I get involved in quite a lot of different research projects.
Certainly, since I started in academia, I've had quite a sort of omnivorous diet, looking at both air pollution, water pollution, hydrology, hydrogeology type aspects. I suppose my research tends to focus more on field studies, where we collect instruments and collect a lot of data in the field, and then we obviously bring samples back to the lab, analyze them, and then we develop a lot of mathematical models as well, which we then use to get further insights into the processes.
I suppose my career, for the first seven or eight years, I worked in industry in the UK designing wastewater treatment processes. So that's what my background was when I first moved into academia. But through the study of more diffuse sources of contaminants, particularly septic tanks, in catchments, rural catchments, I soon got more interested in how contaminants move through the soil down into the aquifers, got more involved in hydrogeology, groundwater engineering, etc.
And I've moved in quite a few different directions en route through academia, so just following different interests, I guess.
[00:02:10] Bridget Scanlon: Yeah. Well, thanks. I really enjoyed reading many of your papers and particularly enjoyed the papers on air quality and whether you should ride your bike or you'd be exposed to more pollutants or take the bus and all of those practical aspects and really fun.
But today we're going to focus on water issues. And thank you. I'd like to talk about water pollution and linkage to agricultural sector and wastewater management. You mentioned septic tanks, also flooding issues, which are a big issue for Ireland and linkages between water and energy. And last but not least, is to discuss how you've been able to link science with the arts through your music and that program, which is fascinating.
So I guess first, let's talk a little bit about the general background of water issues in Ireland. I mean, most people think it's a pretty wet country, it just seems to never stop raining and people ask me when they should go to Ireland and I say, well, you never know. You've just experienced a month of fairly dry weather and today it's lashing rain, you said.
[00:03:12] Laurence Gill: Yeah. It certainly is, yeah. But yeah, I mean, the whole of June was incredible. I think it was barely a drop of rain, but now, now it is, it's making up for it today. I can tell you that.
[00:03:20] Bridget Scanlon: And so when I look up background information, I mean, 85,000 kilometers of mapped rivers, 12, 000 lakes. Most people use surface water as their source of drinking water for 80% of the population, I think, and 20% on groundwater.
So when I was doing my studies in the U.S. early on, I studied karst hydrology and that's water and limestones and stuff because I thought I would go back to Ireland at that point and 40% of Ireland is karst systems. So, looking at the Environmental Protection Agency report about water quality issues, they mentioned that about 40% of the rivers have high nitrogen levels, and rivers and groundwater in the southeastern part of Ireland are under high pressure from intensive agriculture.
Maybe you can describe that a little bit, Laurence.
[00:04:13] Laurence Gill: Yeah, so to give this a background to some of the legislation in Ireland, as part of the EU, we're very much working to something known as the Water Framework Directive, which came into force in 2000s. And basically, what it was asking was that all EU countries that every river, lake, transitional water estuaries and groundwater should get to what is known as a good status, that's good ecological status and chemical status by the year 2027, which seemed quite a long way away in 2000, but of course that's just around the corner now. As, as you mentioned in Ireland, for example, in terms of the water and the rivers, still 40% of the rivers are less than good status. And we've only got a few years to go.
So, realistically, this is, it's not going to happen at all. All the water bodies are going to get to good status, but there's, there's been this kind of structured approach setting up river basin management plans on these six year cycles to try to target sources of pollution and improve the, the status, I mean, a lot of the, a lot of the focus has been on nutrients and a lot of really the majority, I believe of the nutrients going into the aquatic environment is coming from a few sources of agriculture. So I got a crop trees. It's a big industry in Ireland. I suppose one of the things that's differentiates Ireland from many other EU countries is we don't have this legacy of heavy industrial pollution that a lot of, countries like UK or Germany, for example, have so that, there's not, from a research perspective, there's not much to study from that perspective, but it's much more my focus and a lot of other researchers here is on the more diffuse sources of pollution from human wastewater treatment plants as well, but particularly from agriculture and whether it's from fertilizers being put onto the land or from, animals on the land, their feces, et cetera.
[00:06:08] Bridget Scanlon: And so when I was looking at the European Water Framework Directive, it's a good status in terms of ecological status and water quality. I didn't see mention of water quantity, but do they consider water scarcity issues also?
[00:06:25] Laurence Gill: They certainly do things like, from a groundwater, I work quite a lot on, groundwater-fed ecosystems like wetlands and fens, turloughs, et cetera. And from that perspective, the quantity is certainly taken into account, that that's keeping the ecosystem alive.
But you're right. Yeah, in terms of the rivers and lakes, I'm not so sure that is, it's not something that I work on actually, but I don't think that is taken into account so much. It's more the chemical quality and then the ecological quality.
[00:06:49] Bridget Scanlon: Right, right. And what's nice about the European Framework Directive is they talk about just scoping out the issues in the first phase and trying to figure out what the extent of the problem is looking at approaches to mitigate the problem. And then the third phase is evaluating the success of those strategies. I think that's a really nice, logical step by step approach then to evaluate these problems. So you mentioned, the linkage between nutrients and nitrogen and phosphorus issues in the surface water and groundwater, and primarily sourced from agriculture.
But looking at the exports from Ireland, 12 billion dollars, I think in 2020 or 21, 2020, 80% of those exports are agricultural products. And it's interesting that, so that's like almost 10 billion is agricultural products. And as you say, we're, we're not a big industrial country. And interesting also is that three and a half billion to the UK must be a little bit difficult these days with Brexit.
So I assume, the farm lobby is pretty strong in Ireland. It's pretty powerful politically. And so, and then on the agricultural side, they're promoting expansion of agriculture, Food Harvest program in 2020 and Food Wise program in 2025. So on the one hand, you have this push to expand agriculture, more intensive, more cattle, more fertilizer applications on the other side from the environmental point of view, then you're trying to deal with the aspect. So it seemed like there's kind of a disconnect there in what's being promoted from the agricultural side and then what you're trying to deal with on the environmental side.
[00:08:31] Laurence Gill: Yeah, I mean, there's definitely a tension between the agricultural industry etc. and the environmental protection. It is a very strong lobby, the agricultural community, and there's some very, very strong, rural politicians, I mean, rural politics in Ireland is, it's quite, quite a thing. And. , as I work a lot on these diffuse sources of pollution, this quite, it takes quite a while to kind of understand some of the dynamics that are going, I've lived in cities all my life, but , the thing, what is important to people in rural communities and as I guess we'll come on to talk about in a minute, a good percentage of population of Ireland lives in rural, semi-rural kind type of environment and agriculture supplies a lot of jobs, so that, that is very powerful. And, and also agriculture and the Department of Agriculture funds a lot of research, which is kind of pro agriculture as it were, but trying to make things better.
But equally, there's a lot of research funded by the Environmental Protection Agency, which I tend to get my funding from, and , there definitely, there's no doubt about it, there has been conflicts and different interpretations, let's put it that way of the same data that are coming out, which makes it interesting, but I mean, there's no doubt about it that the agricultural community , have been changing and are trying to do things in a more sustainable environmental manner.
But at the same time, they don't want to reduce their outputs. And as you say, if anything, they, they've been increasing the intensity of farming, but I mean, there are clever ways to increase the intensity and maybe not increase the environmental pollution, but that's, that's what's going on at the moment.
There's various different angles of research and that are looking into these types of things. But, from the water perspective, our rivers still aren't good and haven't really improved that much over the last few years, despite a lot of effort into so called programs and measures that have been set up by these individual river basin management plans that are set up in six year cycles to try to target, bespoke plans for different catchments to try to target pollution and improve the matter.
But so, I mean, so far it's been pretty minor, I think, the successes.
[00:10:40] Bridget Scanlon: Right. And I mean we've been hearing a lot in the Netherlands and surrounding countries about impacts of intensive agriculture on environmental quality there. So, I think it's similar issues here. And I grew up in a farm in Kerry in Southwest Ireland, and they kept the cattle indoors in the winter.
And then there was land application of manure in the spring. And so those sorts of things, but it seems like most of the farmers these days have degrees in agriculture. So it's much more sophisticated operation and there are a lot of regulations that they're trying to abide by. So I think they're trying to improve.
So you mentioned, maybe it hasn't improved that much. I mean, are they doing riparian buffers next to the stream to try
[00:11:22] Laurence Gill: Yeah. I mean, there's a lot of, I mean, I think another issue in Ireland and maybe say people in the States. wouldn't appreciate is the size of, there's lots of very, very small farms, people with cattle, 20 cattle, 50, 40 cattle.
It's that scale, and lots of them. So I suppose it makes it a bit more difficult to regulate when you've got so many different people that need to be contacted, et cetera. But, as the younger generation are coming through, there's no doubt about it. They're much more environmentally focused, et cetera.
And, and yeah, riparian buffer strips are a big tool. that's been introduced with various degrees of success is that over the years to try to improve the discharge quality and stuff. Nutrients begin, yeah, directly into rivers. I mean, forestry is another, is another issue that has been targeted.
We have very little natural forest, but there's a lot of coniferous, kind of sitka spruce type forestry that's, industrial forestry. And there's been quite a lot of work on the pollution from that particular sediments. And then, how to improve that. So, I mean, certainly the last 20 years, I mean, a lot of research and activity in trying to understand the pollution and pollution pathways and, and then actions following from that.
[00:12:35] Bridget Scanlon: Right, right. And when you mentioned the size of farms and people here in Texas, where I live now ask me, well, what size was your farm? , I'm embarrassed to say, well, it was like 70 acres and they just think, oh my gosh, that's just like your backyard, ?
[00:12:52] Laurence Gill: Yeah. I mean, like on one level, from a biodiversity level, it means there's a lot more hedgerows, et cetera, but from a regulation, it does make it kind of trickier. I think with so many individuals with small farms to deal with.
[00:13:06] Bridget Scanlon: So another aspect of pollution that you do a lot of and which benefited and leveraged from your work in the UK, your early career there is looking at wastewater and I guess considering the population of the Republic, about 5 million. and maybe another 2 million from Northern Ireland. Much of the area being rural, you mentioned earlier that a third of the people rely on on-site wastewater treatment. And the centralized water treatment is mostly secondary treatment, but then onsite treatment and how well that works and what that is contributing to groundwater quality. Maybe you can describe that a little bit.
I think Ireland was fined by the EU for E. coli early on, for some of their discharges and stuff. So maybe you can describe that a little bit. Laurence.
[00:13:56] Laurence Gill: Yeah, so when I first came to work in academia, because I've been working in these large scale waste water treatment plants, and that was my interest, there was a project by the EPA on septic tanks, and there wasn't much else in terms of research funding available, and I applied for it, and I thought, well, septic tank, sounds a bit boring, and but actually, the more you get into it, how the effluent goes down through the soil, through the unsaturated zone, down into the groundwater.
I mean, it just opened up this whole world of interest, et cetera. And, so I mean, Ireland is, is incredible in terms of the geology, the diversity of geology and, and, and the soils, due to previous periods of glaciation, et cetera. So it's just endless, the sort of fascination in terms of the different permutations of what can happen.
But about one third of the population in Ireland uses some form of onsite wastewater treatment. And the majority of those, probably 85% is septic tanks. And then the effluent goes into the ground. And so I, I spend a lot of time researching how it should go into the ground, how it should be spread out evenly for different soil types, such that as it percolates down through the soil, you get treatment of potentially pathogenic bacteria and nutrients, et cetera. And also trying to minimize greenhouse gas emissions is something we've been looking at, a lot more recently, looking particularly more at the microbial diversity of what's going on in the soil and how we can kind of tweak that to minimize greenhouse gas emissions and also optimize the pollutant removal capacity of soils.
So there's a couple of issues, one of the main issues really in Ireland is low permeability subsoils, particularly up in the northern half of the country. So that the last period of glaciation left, left kind of heavy boulder clay across a lot of the country, which is very, very low permeability. So what that means is a lot of this land can't even take the rainfall, let alone this additional wastewater that's been discharged into it, so means a lot of the effluent, goes through very shallow pathways, probably directly into a lot of streams into watercourses without being treated. I mean, the soil itself, if you get unsaturated, one meter of unsaturated soil with reasonable permeability, it can be, really excellent treatment medium. So if it's done correctly, it's a very effective, very sustainable form of sanitation. But in low permeability scenarios, we have to sort of rethink it. We've been doing a lot of work recently trying to enhance evapotranspiration using like willow trees, for example, as a concept to lower the load on the soil.
And then in some other parts of the country, we got too fast, particularly down in Southeast, it's potentially too fast. And that can lead to think particularly things like nitrate pollution in the groundwater underneath. So, I sort of ignored it, I guess, when I was younger, but I mean, it's estimated about 3 billion people on the planet use some form of onsite sanitation.
So, the more work I do into this, the more I think, I mean, first of all, it's fascinating. and it's, trying to use passive treatment nature based type solutions, as much as possible in this very kind of dispersed environment where there's, there's very little regulation.
Your average person doesn't spend ages maintaining their septic tank. So these types of things have to be very kind of robust, et cetera. So it's a very interesting area of study. And then that very much led on to looking at contaminant pathways through, if you find, say, groundwater has been contaminated, where has the contamination come from?
Has it come from agriculture or has it come from human wastewater? So the human wastewater is... as a source of contamination is more worrying from a disease perspective, because most diseases we catch come by kind of humans. I mean, there are some that cross species, but most of the big ones come directly from human efforts.
So we've done quite a lot of work looking at, contaminant pathways from septic tanks versus agriculture, and then various types of risk analysis on those at a kind of catchment level, etc. And how can we mitigate that impacts? so just, in terms of the, I know you said the statistic that 80% of people in I in Ireland use surface water, which is, I mean, there's no, that, that, that's true.
It's, it's kind of disproportionately affected I think that because Dublin is by far and away the largest city and Dublin, we are right next to the Wicklow Mountains here. So there's big reservoirs effectively up there that supply the whole of Dublin with surface water. But in rural areas, the use of groundwater particularly kind of single wells for individual houses is much higher, in rural areas.
[00:18:31] Bridget Scanlon: Yeah, I know. Growing up, we had our own well, but then we, after a while, maybe when, 10, 15 years, we linked up with more of a centralized system, but we still had the well as backup. So you, you also do research and trying to fingerprint the source of contamination.
Maybe you can describe that a little bit. You mentioned human and animal sources and, I read sometimes about cryptosporidium outbreaks in West Ireland or different regions and, so maybe you can describe that a little bit.
[00:19:02] Laurence Gill: Yeah, so the sort of traditional measures of pollution is to say, somebody suspects their well, their private well, is polluted, they might take a water sample and they test it for E. coli or sometimes ammonia or nitrate. And that can certainly give you an indication that there might be some sort of fecal contamination, but what it doesn't do, it doesn't tell you where it's coming from because mammals and birds produce E. coli and produce nitrogenous waste. So, what we've been trying to do over the years is to look at more specific compounds that we can say, look, that must have come from humans and therefore not from agriculture or vice versa.
Some things we've looked at are things like caffeine, pharmaceuticals, which are obviously synthetic, artificial sweeteners that, are used in food stuffs and drinks instead of sugar because they don't break down very, very readily in the environment. Another thing is fecal sterols. So when we break down cholesterol in a body, we break it down to certain byproducts. Whereas a pig, for example, breaks it down to different byproducts and then a cow breaks it down to a different byproduct. So by looking at these kind of ratios of these degradation compounds, we have some, you can say that that must come from human effluent, et cetera.
Another one for, for fluorescent whitening compounds. These are used in detergents and just quite easy to monitor for. So again, we've used those in different situations, some of these better or worse. I mean, the problem about things like caffeine, pharmaceuticals, artificial sweeteners are that they're costly, that they're expensive to analyze for, and it's quite costly and you need very specific machines.
But something more recently, I'm quite excited about is the sort of, the sort of rise and ease of medical biological techniques like DNA sequencing, et cetera. We're starting to do a lot more work looking at very specific microorganisms that we know must come from a human versus from a cow or a chicken or something.
So that there's a bacteroides species of bacteria. Some are very specific to humans, some are specific to cows. And then more recently at the moment we're doing trials today actually, where we're, we're dosing Tabasco sauce into septic tanks fields. So when you eat peppers, there's a virus called a pepper mottle virus that infects peppers, peppers that we eat and it's totally harmless to humans, but humans, but it goes through us. So we're starting to use this as a tracer. So if you pick up the pepper, it must come from some sort of human food source, etc. And the aim is to see how, when it goes down to the soil, does it get bound up in the soil? Or, or is it more mobile and makes its way down into the groundwater, etc.
And then we hope maybe you can use that as some form of tracer. So we do a lot of research on this type of aspects, specific compounds? How do they break down as they're coming down through the soil? How persistent are they in relation to maybe more pathogenic forms of pathogenic organisms that we're really worried about?
[00:21:54] Bridget Scanlon: Yeah, it's funny, people ask, do you drink coffee or not? But maybe even without explicitly drinking coffee, maybe drinking it in the water and you were getting the caffeine in the water. So that's extremely interesting because I mean in order to treat the problem or deal with the problem then it's important to understand the source and then it may be that your septic tank is too close to your well or or maybe need to be locate the well in a different place to avoid the pollution.
You mentioned earlier the water governance aspects and the European Union and the Water Framework Directive that was established in about 2000. And then the Irish Environmental Protection Agency was created in the early 90s, 93 after passing the Act in 92. And then also Irish Water was created in, in 2013, Uisce Éireann.
And then in that time period, they were talking about charging for water, and I can remember the uproar there was. Maybe you can describe that a little bit, what Uisce Éireann, or Irish Water, is, and, and what they were trying to accomplish and how that has evolved.
[00:23:07] Laurence Gill: Yeah. So it seemed like a good idea at the time. Every county local authority had their own, they dealt with their own wastewater and drinking water. So, they had their own engineers and et cetera, dealing with that. And, some of these, these counties are very small by international standards.
So, I think it made sense to get it, to centralize this expertise, et cetera, to take over the running of the centralized water and wastewater treatment works. And when it was set up, the idea was to charge people for water, as happens in most other countries, really. And in the urban areas, they went around putting in water meters, which again, seemed like a very sensible thing to do, to be able to quantify how much water people use.
[00:23:50] Laurence Gill: And then one of the key things was to be able to identify leaks and then to notify people, well, either Irish Water themselves didn't know about the leaks or to identify, tell people on their land on in their property that there's leaking. Can you do something about it? But it was, I think it's fair to say it was kind of poorly introduced in that it was just it was just seen as an additional tax. It was an additional tax. There was no extra money people would have to, to, to spend on water without seeing the benefit on the other side. Because I mean like we all pay for water, obviously we pay, it's via central taxation, but it's not a direct cost. So I think, I think about six months, nine months, they did charge for water, but there's marches, demonstrations, all, and it was very contentious.
But in the end they rolled back on it. So we have Irish Water and we have all the water meters, which are still being read, which are very useful from a data perspective. But we're not getting charged directly for water. So, there is this, there is this kind of misguided notion with some people that sort of, water is free and should be free.
I mean, it's not free. I mean, there's a massive infrastructure to produce water coming into your tap. And also just as important, more importantly from my perspective, the waste water. So, when you flush your toilet, how it gets treated, et cetera. And that wasn't sold very, that wasn't explained very well, I don't think at all at the time.
But anyway, that happens, so we don't pay directly for water, and it means, really it means it's still very underfunded, I believe, the water sector in Ireland.
[00:25:14] Bridget Scanlon: I was looking up some of the aspects related to that, and it seemed like they were going to provide above a certain baseline amount for free, 80 litres per day for free per person, that would be 20 gallons per day, and then above that then they would be charging maybe
5 cents per liter or 2 cents per gallon, but I do remember that one of my siblings in Wicklow installed a well at that time because she had a fairly large family and so was concerned that, all the showers, et cetera, so it was an interesting time, but it's nice that you have the legacy now of all these water meters and then you can quantify how much water people are using and, and changes in demand.
So that's important data to have.
[00:25:58] Laurence Gill: I mean, it also, I mean, at the time, there was a lot of debates about rural versus urban living, because, people with centralized facilities would have to pay for water. Whereas people in the country, like you say, with wells didn't, and then there's other debates about, oh, how much money people are spending on roads versus water.
So it opened up a whole kind of can of worms in the country, really about, proportionality of taxation. What do we pay for? And, when we live in different places. So yeah, it was quite contentious. And, and it's interesting. I mean, for example, in Denmark, if you, if you live in the country with septic tanks, you have to pay a fee to the government tax to discharge your effluent into the soil and because it's deemed as a, a form of potential pollution and that led to a lot of people just designing closed basin evapotranspiration willow treatment systems for not from the perspective that they that we have, where we have low permeability soils and it won't work.
But they did it from a financial perspective, just so that, so they, they argue, well, there's no discharge into the soil. whereas now we're using these types of basins to, in areas where the soil is, is too, too low permeability to take the effluent. Yeah, I
[00:27:06] Bridget Scanlon: I mean, there, there's a lot of discussion these days about a sort of vulnerability and, and water access and water being a basic human right.
And we had a National Academy discussion maybe about a year ago, and they were pushing forward Ireland having free water being very advanced.
[00:27:25] Laurence Gill: Yeah, I mean, of course, it is definitely a human right. And, I think South Africa was one of the first countries that introduced this, this certain amount for free.
And then this kind of rising scale, as you use more and more, you get charged proportionately. And, of course you don't want people cutting back from the amount of water they use from a health perspective, but at the same time, you want people to feel that you can't just leave taps running non stop and it doesn't matter. So I think there's a balance there somewhere.
[00:27:50] Bridget Scanlon: So we've talked a lot about water quality issues and linkages to agriculture and wastewater and onsite wastewater treatment systems, but another big issue in Ireland in terms of water is flooding. I mean, everybody thinks of Ireland's... being a very wet country and that's why it's so green.
But one of the issues with that then is flooding. And I was just looking at the Irish times and they said one of the headlines just recently was Tralee was hit by biblical flash flooding a few weeks ago in June. And then, various years where you had a lot of flooding, maybe you can describe that a little bit Laurence and, and what they are doing to try to alleviate some of these issues.
[00:28:31] Laurence Gill: Yeah, so, I mean, it seems, I guess, alongside a lot of other places in Europe and probably the world, that frequency of severe flooding is increasing and, it's been attributed to changes in the climate, etc.
So, I guess, in Ireland, the two main sources of flooding is fluvial flooding, particularly from some of these very low permeability type catchments, very fast runoff off the soils that is probably what was going on down in Tralee.
And then groundwater flooding, which is something I work on a lot. So I, again, kind of a legacy for me from working in industry in the UK, I used to do a lot of modeling of sewer networks. When I first came here, one of your academics here had was working on karst systems and, we had this idea that we could model these, these underground conduits using the same principles as, pipe networks because you, unlike most kind groundwater systems that, you get turbulent flows through these, the, these pipes.
So I started to work on mathematical modeling of some of these systems that are out in the west. So we have a karst as you say, across probably half the country, but some more recognizable areas of karst are certainly in, in the west. A lot, a lot of our karst is underlain by quite low level, lowland karst and underlain by quite heavy deposits of soils.
It's not maybe as spectacular as some places you might see in Europe or America, but we do have places like the Burren, which are, you have the more kind of classical karst scenery, but the lowland nature of a lot of our karst systems means that we do get quite a lot of ground with flooding where the water level come to the surface from, from these karst systems and floods the lands.
Now, the, the flooding, the speed of flooding is much slower. The rise, if you like, of the flood waters much lower than the sort of more fluvial flash floods that you get. But it, but it, it hangs around a lot, lot longer. So from a kind of damage perspective, it's more insidious, I guess.
In quite a lot of karst areas, due to this lowland nature, we have these lakes, these ephemeral lakes, which are known as turloughs. So turlough in Irish means dry lake. So in the summertime, it's like a field, like an empty kind of bow shaped field, and, cattle graze in it, etc. But in the wintertime, the system underneath, becomes over pressurized, if you like, and...surcharges up into the basin and creates these lakes and then there's turloughs and these things bounce up and down according to the rainfall. And, and when we first started doing this, we were looking at the ecology because you get very unique vegetation that can sort of tolerate these fluctuating conditions, flooding conditions.
But of course, under really extreme rainfall, everybody knows where these turloughs are, and , you wouldn't build a house in the middle of a turlough because it would flood every year. But in extreme conditions, these go beyond their normal boundaries and create groundwater flooding.
And this seems to have been getting worse over the last 20 or 30 years in some areas. So there's a particular area in South Galway with some very big conduits underneath the ground, very big cave systems and many, many turloughs at the surface that we've been studying for. Well, I've been studying for 20 years, but it's been going on a long time.
And we're using these models that we've developed now to develop flood alleviation systems. So once you get to certain levels, having these overland bypass channels to take the water down to the sea more quickly to sort of take the top off the flood such that you, the area isn't flooded for sort of two months at a time.
I mean, this has been going on for quite a long time. It looks like we're getting closer and closer to this and getting past planning permission, et cetera, and actually being built. , we don't want to interrupt the ecology. We do want the systems to flood and have the same kind of ecology. But in these really extreme periods, we don't want to be flooding the people's houses and railway lines, etc.
So it's a very interesting project. And then there's all issues about taking floodwaters directly down into the bay and how that impacts on the aquatic life in the marine. So trying to, we're having to model the marine environment as well. So it's all very interesting. So there's two agencies.
There's one, the OPW Officer Public Works that looks more at that. Well, they're involved in floods or flood risk assessments for rivers and groundwater. And then the Geological Survey of Ireland, they specifically more on the groundwater side. And, over the last many years, they've been coming up with flood risk assessments for different parts of the country, designating some lands as what one in a hundred years, this might flood once in 50 years, this might flood, et cetera. But the karst systems are so kind of specific that, you need, it's very difficult to have a kind of generic model for them, I think.
[00:33:03] Bridget Scanlon: Right. Well, you definitely see the linkage between groundwater and surface water in those areas. I mean, oftentimes, we manage those systems separately and they're very siloed. But I mean, in that system that you just described with the water table rising and then creating this ephemeral lake, you can see that the groundwater and surface water highly connected. And then with the karst system, it's kind of like an underground river system.
And so it's easy for people to understand how groundwater is somewhat similar to surface water. So these are nice examples. And yes, I mean, it's nice that you're maintaining the ecosystems and stuff, but then also dealing with the excessive flooding and trying to drain that off and then considering potential impacts on the coastal waters.
So there's a lot of discussion these days on energy issues in Europe and with the war in Ukraine and shortages and all of that sort of thing. But in Ireland, you were describing some of the linkages between groundwater and energy with the example in Trinity of those heat pump wells that are installed in front of the museum building.
Maybe you can describe that a little bit,
[00:34:12] Laurence Gill: Laurence. Yeah, so I mean, in terms of say, the picture of renewable energy here, the main thing has been wind energy over the last 20 years. So that represents about 30% of the electricity and there's more plans for wind turbines out and, deeper offshore, etc.
But, really, It only targets the electricity produced electricity, but in terms of the heat sector, the vast majority of our energy is from gas and oil and some extent coal. We used to burn some peat as well, which I guess we can come on to in a minute, but that's been phased out. So there's a sort of nascent interest that's now building in terms of geothermal energy in Ireland, which I'm starting to get, I'm starting to get very interested in and as are other others. And, I think realistically for most of Ireland, we're talking about quite low entropy type systems, shallow, shallow, geo, so we don't have hot rocks close to the surface like they might do in the States or Italy, although possibly some potential up in, in the North of Ireland. But, I think in general we're talking about relatively shallow, maybe down to a kilometer or shallower type systems. And it's just starting to be looked at more seriously in a few large scale projects for sort of more district heating type approaches are being, starting to be constructed and designed. So here in, in Trinity, there's a, Trinity is a very old university, 1592 it was set up. And there's certain areas that you think would be hallowed ground and never be touched, but, just outside, which there's a little square outside my building that Bridget knows very well and, it's been dug up over the last two years and they've drilled 22 wells, geothermal wells down to 180 meters. And then these, these are now going to be heating two, quite two big accommodation blocks, old accommodation blocks that have only just been switched on literally a few weeks ago, even in the summer.
So we haven't really tested them yet, but that's the idea. So it's, it's great. We get some data and I'm interested in modeling that groundwater side of that. And also, in the more kind of suburban areas, we've got tight amount of land, can we realistically use some of these shallow geothermal type ground source heat pumps as a concept?
There's quite a few people use them out in more rural locations where they have, bigger gardens or areas, et cetera, but it's something I think is an increasing amount of activity in the next. a few years. Right.
[00:36:39] Bridget Scanlon: And so maybe you can describe that a little bit. I mean, so you, is it a closed loop system intrinsically then that's planned?
And do they put the water on the ground then? And then the ground heated in the winter then, and then circulated in the buildings then to heat the buildings in the winter?
[00:36:54] Laurence Gill: Yeah, no, it's a closed loop system. So you're not using the direct water from under, underground. So there's a heating fluid goes down into the ground, which picks up the heat, the heat from the groundwater and comes back up. And then that goes through a heat exchanger, which transfers the heat into the water that then goes into the radiator system in the building.
Now, in some scenarios, you're going to build a so called open loop system where it loops it, where you're actually taking the water itself, from the ground water up, take, extracting the heat.
And then you have to inject that back down somewhere else, the cold water, obviously away from the source where you're picking up the hot water. So it depends on the nature of the groundwater as to which is more effective and which should be used, I think. And
[00:37:40] Bridget Scanlon: theoretically, you could use that also for air conditioning if it gets too hot in the summer, is that correct?
[00:37:45] Laurence Gill: Yeah, yeah. Not normally a problem here in Ireland. Well, you never know. Yeah, I mean, it's interesting because again, I see things from a sort of Northern European perspective and we always worry about our main energy uses in the winter for heating, but of course, in other countries, it's, maybe in Texas, I don't know, air conditioning is one of the main energy and uses in hot weather. Right?
[00:38:10] Bridget Scanlon: Right. And so there's a lot of discussion then about energy sources and that has been changing in Ireland, as you mentioned, increasing wind energy. And some of the statistics I was looking at almost 50% still relying on natural gas and some electricity power plants based on oil. And, but in recent years, then they've been closing down the power plants that were using turf for ESB closing down these and one slated Edenderry, I guess, is slated to be phased out this year. So maybe you can describe that a little bit, but people can still go to a bog and cut their own turf and, and store that turf for household heating, but not any industrial uses. Is that correct?
[00:38:53] Laurence Gill: Yeah. so in Ireland, particularly in the Midlands. We have these a lot where we used to have a lot of raised bogs that, developed over 10, 000 years of accumulation of the moss, the sphagnum moss growing. And I think from about 1940s, I mean, and people have used that in rural locations that they cut the turf, dry it out and burn it. It's not amazingly efficient as a heat source, but it's there and it's available.
But then a state company was set up called to industrially harvest these.
I think it was providing up to about 40% of the electricity in Ireland. But I mean, the last 10, 15 years, it's been down at about 8% of the electricity, natural gas and oil have been by far and away the major suppliers of electricity. It's been, it's been deemed to be not great from a climate perspective and also from an ecological perspective.
But I mean, there's vast tracts now of the Midlands are just these blank, excavated peatlands with almost no vegetation growing on them. So last year, the government decided to stop all industrial harvesting, and then they've set up a scheme known as PCAS, Peatlands Climate Action Scheme to try to reverse this and, and bring these, to try to get these peatlands to start to grow again, basically to rewet the peatlands so that they start to, the sphagnum, the moss starts to grow again, starts to lock in carbon, which is a very slow process, but also, start to generate proper natural bogs with all the biodiversity benefits.
So this company Bord na Mona are now calling themselves a climate solutions company. And, they have this extensive scheme to rewet all these thousands of hectares of excavated peatlands, and we're now starting to do a lot of research into this as to how, how do you hold the water back, you can do it by blocking drains, etc.
But what is the optimum conditions for the sphagnum to grow? So you can't dry out too much in the winter, otherwise it will die, and , equally can't be flooded too deep in summer, can't dry out in the summer, and can't be too deep in the winter. So there's this kind of sweet spot that's needed to try to regenerate this.
This type, this vegetation, once it gets established, it to an extent creates its own kinda microhydrology. But in the first, 10 to 20 years, it's gonna be tricky to, to get, get this segment to grow. So, so, I work a lot on this kind of ecohydrology and it is very interesting, trying, trying to, trying to get the right hydrological conditions and then, from the model in model what's going on and then, tweaking it, et cetera, tweaking the different levels to try to optimize this.
[00:41:45] Bridget Scanlon: And does this provide work also for some of the people that are working in the local communities? So that, that's an interesting aspect also.
[00:41:52] Laurence Gill: Yeah. So, I mean, I think the government is spending a lot of money on this rewetting of the bogs and, certainly is helping, from an environmental sustainability perspective.
But I think it's also, It's also about the local economy because again in the Midlands, a high number of people are involved in this industrial harvesting of the peatlands, directly employed by Bord na Mona and then all the subsidiary companies that provide machinery, etc. And so suddenly stopping that, we put a lot of people out of work.
So now these people are employed in reverse, using the same machinery, but to build bunds and block drains, et cetera. And it provides employment over maybe a short, relatively short period, but at least it kind of softens that blow if you like in, in these communities in the Midlands.
[00:42:40] Bridget Scanlon: So we've talked a lot about hydrology issues and I was extremely impressed with your program trying to combine science with the arts through music and the Inception Horizon and also watched the performance in the museum building I guess the day before lockdown and then the film and the karst performance in Slovenia in a cave.
Maybe you can describe that a little bit Laurence, it's extremely impressive. And what motivated you to do that? And how is it?
[00:43:11] Laurence Gill: Yeah, well, I suppose it all comes, I mean, I play a lot of music in my spare time. I mean, a lot of it's kind of traditional music, not just Irish music, but I play lots of French, Italian and music is very important to me and I sing in a choir, etc.
But it's always struck me that you can hear a piece of music that you hadn't heard since you were sort of five years old and straight away you can remember the tune or the words. It comes straight back to where it's. I give a lot of lectures to students and I can guarantee two minutes after they walk out of the lecture they can't remember a thing I've said.
So I've always been interested in coming to somehow combine music and other forms of art to help people to understand certain concepts, scientific concepts, or, or any concepts really. And, and this was working with karst idea, can we somehow write some piece of music that mimics the rain falling onto the land, how it percolates down, maybe through the soil, through the epikarst, down into the conduits, getting faster and faster, more and more kind of joining up together and eventually coming out in a spring somewhere.
And I, as I say, I sing in a choir as well. And the person who runs the choir, the artistic director, got quite excited about this. And so she took some of my words and composed this piece of music called Inception Horizon. I took the whole choir and we went down some caves in the Burren, not tourist caves, proper caving caves.
And it was about two years of sort of building up to this and writing, I was writing the lyrics and she was writing the music. And again, that the pace of the music somehow, it kind of drops, the pitch drops, mimicking the water dropping as you come through the system. And then it speeds up as the flow is getting more and more combined.
And so we had this thing in the music, this amazing building that I work in the museum building, just. We'd arranged this event, a public perception event on cast. So it wasn't just this piece of music. There was, we had poets speaking, we had scientists, geologists, etc. giving talks. We had different visuals, different projections onto the wall, onto the stone.
And it was lucky because it was literally the day before we shut the whole country shut down. Covid had just, there's just been a few cases. It was the last day and anyway, so we had this big event and the culmination of this was given, given the world premiere of this choral piece of music, which went down really well.
And then we always planned to sing this in a cave as well somewhere. And originally we were going to do it in Ireland, but then because lockdown changed everything for a couple of years, but I worked out with people in Slovenia, Slovenia is one of the centers of kind of research into karst, they have this so called classical karst in a generic karst in the Balkans and, and they got very keen about the idea, could the choir come across and sing a piece of music.
So we all went over there in this September, last September to perform the piece, which is amazing in these spectacular caves.
And then the other thing we did was there's a UNESCO Futures Festival where we had the the recording of us singing the music and then I took a cameraman into some of these caves in the Burren and we captured footage and we put together a film that kind of cut between us singing in our posh clothing in the Museum Building and then the underground scenario working our way through the cast and system following the flow of the water in time with the music.
And so we submitted that into this competition and it came third overall, which was great in the people's popular choice. So, It's been really interesting, but it's, I mean, it has been effective, it's definitely got more people interested in understanding how water flows underneath the ground in these systems.
And, I'm involved in some other kind of art science type collaborations now on the back of that. And, it's apart from being enjoyable, I think it is worthwhile from an educational perspective.
[00:47:01] Bridget Scanlon: Right. And, I think the UN last year had the main issue was they focused on groundwater and tied with making the invisible visible. And I think certainly karst helps us understand some types of groundwater systems. And then I really admire how you have been able to bring these two things together, science and the arts. And we will include links to these various things on the website so people can access them and listen and watch.
[00:47:29] Bridget Scanlon: So you've been working for a couple of decades now, and you've been trying to deal with the challenges with water. How, how do you see the future evolving? Are you optimistic about the future and think they'll be able to cope with all the increasing climate extremes and things like that, or.
[00:47:48] Laurence Gill: I mean I'm quite optimistic as a person anyway.
I think, there's much more knowledge and information and tools available, tools in terms of analyzing contaminants or mathematical tools or, computing power. I mean, it's, it's unbelievable the speed of change I think in technology, et cetera, over the last 20 years. I mean, maybe people would say it has been for the last hundred years, I guess, but certainly since I've been in research, what we know now.
It is incredible. So, if we have knowledge and we have tools to be able to do it, I guess the final part of the puzzle is convincing people who have control of the money to put resources into solving these problems. But I am an engineer at heart and I believe we can solve, probably we create a lot of problems, of course, environmentally, but I think we have the ability to solve a lot of these things.
I mean, it is slow. I mean, environmental processes are, as we've seen in the rivers, there's big lags in the system. So, that is problematic. I think politically sometimes that you don't necessarily see the results. Very quickly, we have a big project at the moment, trying to date groundwater in Ireland and really it's all about nitrates because there's been a lot of work in trying to reduce nitrates in groundwater and yet it seems to be reducing.
So, how long is the groundwater hanging around there before it gets flushed out, et cetera. But I mean, just for the knowledge and the tool, I mean, we, we have much better insights. And also the more you realize you don't know, of course, so I feel fairly optimistic, but undoubtedly there's big challenges and of course, the predictions for Ireland as a lot of places is more intense storms in the winter and less rainfall in the summer.
So you've got droughts on one side and floods on the other, but, once we have an awareness of that, we can try to mitigate these, some of the consequences of that. Well,
[00:49:35] Bridget Scanlon: Well I agree with you. And I think you use satellite data a lot for looking at the bogs and, and, and how they're changing over time.
So we have a lot of new tools and, and like talking to engineers because they're solution focused and it's not just all crises and, but trying to come up with appropriate solutions. I really admire your work and appreciate all that you're doing. I look forward to visiting Trinity in August and hope we can get together.
And our guest today is Laurence Gill, who is a professor in Engineering at Trinity College, Dublin. Thank you so much, Laurence, for discussing these issues. You have a good day. Thanks for it.
