Episode 10: Water Blindness
Beneath our feet, at the end of our roads, or hidden out of sight, there’s a whole world of water and waste! Managing this is key to human health, from tackling the increasing levels of chemicals entering our water systems, to meeting demands for development. Professor John Williams tells us how Portsmouth is rethinking systems, all whilst creating innovative new approaches to our environment and economy.
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People switch off on water... in this country. We have a disconnect. In lower-income countries, people have a much greater connection with the environment because they're in contact with it more.
Narrator: You're listening to Life Solved from the University of Portsmouth. In this series, we hear about world-changing research from the brilliant minds at work here in Portsmouth. We also find out how that work is making a vital impact on human life.
Narrator: This time, John Worsey is speaking to Professor John Williams. As an expert in environmental technology, Professor Williams is fascinated by the blind spot many of us have to how we use and dispose of water in daily life.
John Williams: I think it's people's awareness. People switch off with water. It's something people have switched off and we have a disconnect. So it's quite interesting. In lower-income countries, people have a much greater connection with the environment because they're in contact with it more.
John Worsey: Yes.
Narrator: Professor Williams is working with scientists across the board to study, experiment with and dream up smarter ways of handling water usage sustainably. Whether that's in the way we build houses in towns or how we design our world to integrate with the environment and weather.
Narrator: John works with chemists, biologists, geographers and a host of different disciplines in order to do his research.
John Williams: My area of research is around water engineering, particularly water quality. The main applications of that would be wastewater treatment and sustainable drainage.
Narrator: John specialised in finding ways of getting clean and safe water to and from our homes and workplaces. But all of this means we need to have a firm understanding of the whole environmental cycle. For that reason, he's very aware of how it's all connected and on very different scales.
John Williams: Hydrology is something I've always had an interest in and I think that's probably why I ended up working in wastewater treatment in the beginning. The sustainable drainage is a similar motivation in that it's using natural processes to bring about improvements in water quality, which has knock-on implications for the general water environment, quality of rivers, the habitat provided by rivers. 90% of what I've done has been about technologies. It's been about improving technologies to give water quality improvements with either lower energy or lower inputs of chemical plant or chemicals. So looking at making wastewater treatment more sustainable, completing cycles around nutrients and how we can do this in ways which are appropriate to the conditions we find ourselves. For example, small rural wastewater treatment works have very different drivers in terms of what technologies are suitable for them, as opposed to large centralised works which are very highly automated and very highly controlled, process controlled. So it's, yeah, the low intensity end of the wastewater treatment is probably where we spent most of my emphasis.
Narrator: Firstly, let's talk about wastewater. It's a topic many of us might like to flush away, but that's half the problem. Have you ever thought about where everything you pour down the plughole goes? John told us how FOG – that's fats, oils and greases – and other items can cause a problem in the unseen world beneath our streets.
John Williams: We've also done quite a lot of work around understanding how wastewater systems are abused by the public. So, for example, quite often put pharmaceuticals down toilets when they shouldn't or we have by-products of pharmaceuticals in people's wastes. And these, of course, enter into the wastewater works and can end up either in rivers or through the separation of sewage solids or going back to agricultural land. So did a lot of work modelling those. Also people, I think through a lack of understanding, they abuse sewer systems by putting things down there they shouldn't. Physical objects – classic at the moment is the cotton buds, which are a particular problem. We put sewage through the screens either as a first stage or before storms are discharged and end on a cotton bud passes through a six mill screen. So cotton buds, wet wipes, the classic. And we've also done work on fats, oils and greases. We looked at the mechanisms formation, so either through poor kitchen practises, pouring it straight down or inadequate grease control in commercial kitchens, these enter the sewage system and actually undergo quite complex biochemical transformations in the sewers and get deposited. These white deposits – people have seen a lot of the fat berg television at the moment. And actually these are often simplistically described as some sort of just fat, which is solidified. But actually, in the sewers, they react with calcium and other cations in there and form soaps. So these deposits are soaponified because, of course, most of the fats going down the drain are these days are liquid fat with the diets people have. We've looked at the chemical and physical properties of FOG deposits and how that might inform their management.
Narrator: The truth is, our sewer systems and wastewater processing technology can't keep up with the rate at which unhelpful chemicals and substances are passing through it.
John Williams: We're returning these biologically active compounds back to the environment. Some of the impacts are well documented, such as the feminisation of male fish in rivers. Others, only just starting to understand. I'm not an ecotoxicologist, but we've looked at this in collaboration with companies like AstraZeneca to really understand which wastewater treatment processes are most effective at removing particular chemicals.
John Williams: We've got work going on at the moment around the issue of microplastics with a PhD student who's developing automated methods to enumerate microplastics in wastewater. So, again, we can understand fate: where they end up, what the level of the problem is, and also whether these compounds are vehicles for transmission of other compounds or other pathogens.
John Williams: I mean, a lot of them come from sources such as washing. I mean, I think there's been quite a few mentions in the paper about fleeces, washing sort of synthetic products with fibres in...
John Worsey: Tiny things that come off...
John Williams: to microfibers. Yeah.
John Worsey: Right.
John Williams: A whole range of sources say this it's completely ubiquitous all around us. We're in a sea. Beyond the combined sewers we were speaking of, yeah, 50, 60 years ago, we changed over to building towns with separate sewage systems. So that gets over a lot of the issues around the combined sewer overflows. But then we've created other problems because these the runoff from towns A comes off at a much faster rate. We get more runoff from urban development than from natural fields. So that causes flooding issues. Also, surfaces such as roads and other urban surfaces collect a whole cocktail of pollutants from hydrocarbons, heavy metals. You can imagine in a city, everything which gets dropped on the pavement, which isn't picked up.
John Worsey: Yeah.
John Williams: Dog droppings or... Everything gets washed off and so this causes pollution.
Narrator: And what about older sewerage systems? There's a problem for towns that were built before separate sewerage systems were incorporated into designs. The impact on the environment is plain. Bet you didn't think you were getting a history lesson on this today.
John Williams: If you think of somewhere like Portsmouth, Victorian cities like Portsmouth, they were constructed with combined sewers. So in Portsmouth, London, old cities, we have surface drainage mixing with our waste, which causes all sorts of engineering difficulties, particularly when we have storm events. And of course, the system has a finite capacity.
John Worsey: Right.
John Williams: And we get something overspills called combined sewer overflows. So in that situation, you can get diluted sewage discharged into watercourses or the sea during storm events, for example, like Portsmouth. And of course companies like Southern Water are doing lots of work to try and disconnect as many surface water sources as possible to manage that, that discharge. That discharge also has other implications, this is the sorts of campaigns you see from surface against sewage and so on about cotton buds on beaches. Most of those are from combined sewer overflows, which you pass through, as I said before, six mil screens and the cotton buds pass then go on through. So people putting these plastic objects down the drain, which shouldn't be there in the first place, primarily because of the flush and forget mentality. They don't understand what the infrastructure is designed for, where the environmental releases from the infrastructure are. The screenings from sewage works, well, contain everything you can think of and more.
John Williams: Quite a gruesome story. I was at a sewage works with a group of students recently, and one of them after my lecture describing what can end up on the screens, ask the process scientist who is showing this round, what's the worst thing you found on the screens? After seconds thought, he said, fingers.
John Worsey: Oh my gosh.
John Williams: So I told my little boy and it made him cry.
Narrator: It might take you a while to flush and forget that story. But John's team's work in this area reveals just how interconnected our forgotten sewer systems are with our environments and our economies. They work with businesses large and small on solving problems. He told us about the team's goal to develop technology that's not only effective in cleaning up wastewater, but which is able to do so in a sustainable and low energy way.
John Williams: We research a whole range of issues related to mainly sewage treatment. We have a specialism around looking at low impact technologies, sustainable technologies. So, for example, we've done a lot of work with constructed wetlands using reed beds for wastewater treatment in the UK, Egypt, South America. And these are technologies which don't have the same intensity of energy use or the same intensity mechanical plant. So they have applications in rural locations, maybe in the UK and also in less developed countries where infrastructure is not around to support more energy intensive, chemically intensive activities. Though we also work with a range of companies who produce wastewater treatment plants in developing new technologies, which may have sort of broader applications.
Narrator: Later on, we'll get to the ways in which you might not have realised drainage and wastewater management is a hot topic for our economy – be it in housebuilding or the service charges you pay on your home. But first, John told us about an experiment he and the team did with an environmentally friendly and affordable water cleaning solution.
John Williams: Well, reeds are just incredible for environmental engineering purposes. First of all. First of all, they're incredibly tough and resilient, but more importantly, they can grow in flooded conditions. So they can grow hydroponically in gravel. This predominantly because they have a mechanism to transfer oxygen from their leaves down through into their roots. If you put your house plant and you just flooded it and left it flooded, eventually, depending on the species it will die. But reeds modify their root zones. In fact, the early reed beds were called the root zone method when they first came into this country, because this means the roots become as well is something keeping the reeds alive, very intensive sites of microbial activity. So if you plant it into a swamp which could have no oxygen in, anoxic or anaerobic, the reed roots will be oxidised. And usually, that's conditions which promote the breakdown of organic compounds. So we've used reeds hydroponically for wastewater treatment. We've also used them for remediation of contaminated sites. So we've worked on, for example, some contaminated lagoons near Portsmouth, which the Ministry of Defence had polluted with fire training runoff to look at how reeds grow in them. And we've had reeds growing in what we believe are UK record levels of pollution for sediments in terms of hydrocarbons – petrolium hydrocarbons. Of course, in SUDs, we get a lot of runoff, especially highways containing hydrocarbons. And we have looked quite extensively at how plants, including reeds, can be used in sustainable drainage to mitigate these pollutants. At our field station, we have a swale. We've constructed a 10 metre long grass ditch effectively, which we've been putting down samples of simulated storm events to look at the fate of these.
Narrator: When John talks about SUDs, he means sustainable drainage. The problem is, that with plenty of major towns and cities running on creaking old sewer and drainage networks, and the residents never having given it much thought, the innovative kind of solution shown in the reed experiment can seem like a distant concept. Oh, and one more explainer for you here. When John talks about predevelopment hydrology, he means what naturally happened to water in an area before houses were built there.
John Williams: Not all developments have sustainable drainage at the minute. But this is technologies which avoid piped systems by either, by mimicking predevelopment hydrology, which either infiltrates the rain into the ground, as it would have done before development, or if we've got an impermeable catchment, stores it and releases it at a rate similar to the greenfield runoff rate. And when that's done in systems, vegetated systems such as grass swales, wetlands and ponds, this water gets exposed to a whole range of treatment mechanisms. So it filters out, oxidises and removes lots of these pollutants. So planning policy, the government environment 25 year plan, all sorts of guidance says that all new developments should have sustainable drainage, mainly since the government decided not to enact some of the issues in the 2010, Flood and Water Management Act.
Narrator: And the plot thickens when there's a debate over exactly who's responsible for managing and updating these essential systems.
John Williams: We're in a little bit of an impasse about the long term management of these systems, the adoption of these systems, who's looking after them. So we're currently just finishing a Natural Environment Research Council Green Infrastructure Innovation Grant, which is looking at how we can maybe help developers understand some of the benefits of sustainable drainage early in the master planning stage.
John Williams: So sustainable drainage is about mimicking the predevelopment hydrology so that you're either infiltrating or storing that. Now, this comes in a range of forms. What's the balance basically between evapotranspiration, what goes back up through the plants what gets pooled on the surface, what infiltrates into the ground and what comes off as runoff. And one of the key parameters there is how permeable the catchment is. So in a chalk catchment, a lot of it would soak into the ground. On a clay catchment, most of it would flow off the surface, but it will flow off the surface at a rate which is held up by its passage over the roughness of the vegetation. So you build a conventional development, you build impermeable surfaces, you reduce infiltration, you create more runoff...
John Worsey: Take it away.
John Williams: And it comes off the surface at a faster rate because the surface is smoother. So there's this camp of, say, companies who build hard engineering underground storage tanks or oversight's sewers, for example, the Thames Tideway Tunnel were massive engineering project in London to store the water, mechanical and civil engineering devices. But there's another camp, I won't call them a fundamentalist, but there are people in the SUDs community who say if it doesn't have source control, that water is dealt with, is close to the ground as it falls and doesn't go through a treatment train of a series of different processes, preferably vegetated, then it shouldn't be called sustainable drainage. So we have a little bit of a fractionated community.
Narrator: Perhaps now you're starting to look at your local urban landscape in a different light. And even if there's debate in sustainable development community, it looks like there's a whole heap of expertise and multidisciplinary science going into the conversation. One thing that plays a big role in decision making is how the land in an area is going to be used – do you go for a wild and rural wetland system or hide it away underground? There are multiple benefits to putting open space wetlands and ponds into new housing developments, as John explained.
John Williams: A) you've got first of all, obviously flood control benefits, but then you've got a water quality improvement as it passes through. So improving river water quality and downstream habitat. Within the development, one thing we found people like is the fact that there's habitat within the development. People value having wildlife within their housing development, although we, of course, have to be slightly wary from an engineering context that these some of these systems, especially for pollutants which are not biodegradable, for example, heavy metals, they will accumulate in there. So we do need to manage them. So we need to think about that. And also, having green space proves the amenity of the urban design, encourages people to be more active as health benefits, air quality benefits, the multiple benefits can probably go on and on. So those are more easily realised than an underground storage tank. But the underground storage tank, you could probably stick a car park on top and you haven't lost any development area. So it's this trade off between these two. Our interest in this is really come about from our initial working constructed wetlands for wastewater treatment. We became involved when the Newbury bypass was built in the 90s. We were looking at the water quality improvements that the ponds, which were built along the bypass along with the porous tarmac were giving, and then we moved on to housing developments, very much more water quality perspective and from a hydrology perspective, looking at the technical aspects of it. But more recently, we've moved over to trying to look at the economic and social aspects by developing some multidisciplinary teams of their colleagues.
Narrator: The other deciding factor, is just how these wastewater and drainage systems will be funded in the future. That's where the cost of sustainable drainage solutions become an important part of John's research.
John Williams: We delivered by hand 3000 surveys to residents living on estates with sustainable drainage to understand their perceptions of the technology, the benefits and the problems. We looked at the planning process and how SUDs can facilitate planning. And also looking at what's the relationship between having, especially green infrastructure SUDs, what effect that has on maybe house prices or sales of houses. The main issues is, of course, if you put in a nice vegetated system and some green space in a development to store water or a wetland or a pond, you've actually removed some of the area of that development, which could have houses built on it.
John Williams: Traditional piped drainage, the design of that is based around one key factor, which is to get the water away from where it falls as quickly as you can. So road drainage, you don't want ponding on roads, housing developments, you don't want flooding. So that's basically how the design calculations are, how big a pipe do I need to get away? So that causes the downstream problems of flooding and pollution.
Narrator: As John discovered, there was no one size fits all answer for every local council in development. Different local needs and resources, both natural and financial, all play a role in making decisions about developing SUDs.
John Williams: Some local authorities would adopt some sort of SUDs, others won't. So we have a difference between locations, between water company areas. So it's very unclear to a developer how their SUDs, if they include them, will be with they obviously want to sell the houses, then leave the development and not have an ongoing responsibility for maintaining the drainage system.
John Worsey: Yeah, that makes sense.
John Williams: And some of this actually means the residents pay a service charge.
John Worsey: Right.
John Williams: So some of the sites we've been using as case studies, residents are paying, some of them object quite strongly to this that they're paying £200 a year to maintain ditches – it's what they describe it to the local papers. So this was just in response to our observations that policy and costs and economics and all these things were the limiting factor, not the technology.
Narrator: John was keen to find the answer for smaller, less-resourced waterworks – this didn't necessarily mean building brand new SUDs for an area. He worked with the local water network to look at how small scale sewage works might get an affordable, sustainable makeover.
John Williams: Well, our biggest project at the moment is probably still in progress, which is a collaboration with Southern Water, where we're specifically looking at the challenges they face at small sewage works. We have more and more stringent discharge standards being put on small sewage works to comply with legislation such as Water Framework Directive, particularly around nutrients, particularly around phosphorus. And the technologies which we typically use at these small sites, well, they have very high requirements for chemicals and the chemical dosing, which requires a large infrastructure on site, it requires energy, it requires chemical storage, it requires a potable water supply for emergency showers, for health and safety requirements and also some operational control. This, if it was expanded out to the hundreds of small sites treating a few hundred people, would, a) be very, very expensive and b) probably not environmentally optimal. There could be, well there are, we know, other ways this can be done, which would be, shall we say, more sustainable, but also more economical. And so looking at passive systems, using maybe reed beds, supplemented with media, which can remove the phosphorus, would allow these small sites. Some of them don't have electricity, some of them don't have water supplies, some of them at the end of very windy paths where it's difficult to get chemical tankers in. So in these situations, having a passive system which operates just under the gravity would be very attractive and just requires position every few years. So. So, yeah, it's about coming up with a better way of doing something for across a range of indicators than what we're we would do if we just applied the technology we used on larger sites. Working with natural processes, sometimes we have to modify them or intensify them. But yeah, working with natural processes.
Narrator: It's pretty good to know that where we may not be aware of the challenges facing our everyday resources, there's often a brilliant team of scientists coming up with ideas like this to keep our world going round – and in ever better ways. But how does Professor Williams think our water blindness needs to change in order to make the biggest difference?
John Williams: I think a lot of the problems are just down to public awareness. Particularly in this country, because of the structure of our authorities and the structure of water companies. So in areas where you, countries where you have maybe more decision making at the municipal scale and there's often more debate about what new technologies should be used to manage the water environment, people tend to be more aware. So in terms of SUDs, I think it's people's awareness. People switch off at water, it's something people have switched off in this country. We have a disconnect. So it's quite interesting, in lower income countries, people have a much greater connection with the environment because they're in contact with it more. And using resources more directly. Whereas in the UK, there's this barrier. So developers who might be looking at adoption involving a service charge, people might want to emphasise that aspect of it, there's yutes living here or something. And also looking at this idea of cues to care. It turns out that a lot of the literature around public perceptions of green infrastructure is people say they like natural things, but when they look at they really don't. They like to see trimmed edges of lawns, they like to see things looking neat. So I think we're currently looking at developing some some some guidance around how you might make, even if you wanted something to be as natural as possible, you might make it look like there's a definite cue to it's being cared for. And even if you don't want to get in there and cut down the vegetation in the middle, at least trim the grass around the edge, and then people might be much more accepting of that. So we've probably moved into areas of psychology now, about people's perception of the urban poor around them. But that's some interesting ideas coming out of that research. People quite like the idea that they've got something which is giving good drainage and water quality and other benefits. But a lot of those benefits are actually off-site. It's the quality of the local river or downstream flooding rather than what's happening in the development.
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