From airplanes to reed beds: a modern airport's water management with Ian Waghorn at Gatwick Airport

[00:00:00] Piers Clark: Welcome to the Exec Exchange. 15 minute podcast in which a leader from the water sector shares a story to inspire, inform, and educate other water sector leaders from around the globe.
[00:00:11] Piers Clark: My name is Piers Clark and my guest today is Ian Waghorn, the principal environmental water engineer at Gatwick Airport. In fact, he is Mr. Water for Gatwick Airport.
[00:00:23] Piers Clark: Ian, brilliant to have you with us.
[00:00:25] Ian Waghorn: Really privileged to be here, Piers. And yeah, I'm a big fan of your podcast.
[00:00:29] Piers Clark: Now, we always start by trying to find out a little bit about our speaker. So tell me, what did you do before you were in the role you are in now? How did you get into this role?
[00:00:37] Ian Waghorn: I always feel like I've got a bit of imposter syndrome when it comes to the water industry 'cause my background, started as an apprenticeship in a mechanical services design. Went into mechanical contracting, so installations of air conditioning and that kind of thing for years and years. Ended up running my own business.
[00:00:55] Ian Waghorn: Moved on from that into facilities management particularly for British Airways at Gatwick Airport in 2004. Then I moved into basically working in construction handover for Gatwick Airport itself.
[00:01:09] Ian Waghorn: We were working on some big flood alleviation schemes, reservoirs and things like that. And the guy who was doing the role I'm doing now, went for early retirement. I was saying to him you can't leave 'cause nobody else knows all the stuff that you know about the airport, about the water. And he said, " Actually, you know quite a lot about it, Ian." He said, "why don't you go for the job?"
[00:01:31] Ian Waghorn: And I thought about it and I thought, yeah, that would be fantastic.
[00:01:34] Piers Clark: I love this idea, that it's like a king crowning a successor. You realize that means you get to choose your successor when at some point in the future you decide to move on to something new.
[00:01:45] Ian Waghorn: Absolutely. I will anoint him or her with some Gatwick water.
[00:01:50] Piers Clark: Now, when we met, you opened my eyes to just how complicated and extensive, the water management assets are that you've got on a modern day airport.
[00:02:02] Piers Clark: So can we now take a minute or two just talking about what assets you have to manage and if you can gimme some figures around usage and things like that so that the people listening to this get a sense of the scale.
[00:02:13] Ian Waghorn: Gatwick Airport itself is like a town. There's at least six and a half kilometers squared of catchment for surface water. So it's about the same size as Gibraltar.
[00:02:23] Ian Waghorn: But just in terms of mains water, we use about 750,000 cubic meters of water a year. We've got thousands of toilets, 40 million passengers a year coming through the airport.
[00:02:35] Ian Waghorn: But probably the biggest aspect is during the winter we have to de-ice aircraft so that it doesn't affect the aerodynamics as they take off. That deicer has to be non-corrosive. So we use something called monopropylene glycol to de-ice the aircraft. And it only really needs to be three degrees and approaching zero degree C before we actually apply the deicer. So a lot of deicer gets supplied.
[00:03:00] Ian Waghorn: The problem with that its then being washed into our drains by the rain. So we do a lot of work to try and manage that because we don't want that deicer going into the local rivers, the River Mole, which runs through and underneath even the airport.
[00:03:14] Piers Clark: Just before we talk a bit more about what you do with the deicer, so let's just pause for a second because Gatwick Airport is built essentially in a floodplain, and you've got a number of key strategic rivers as you've just mentioned, flowing through the area. One being the River Mole, which actually I suspect most international listeners won't have heard of, but you will have heard of the River Thames and the River Mole flows into the River Thames.
[00:03:39] Piers Clark: And I love that stat of you've got the same size as Gibraltar. That's a good statistic to have, same catchment footprint as Gibraltar.
[00:03:47] Piers Clark: Now, seasonally, you've got this deicer fluid and there's no question, there's no alternative. You can't use anything other than deicer fluid, I assume.
[00:03:56] Ian Waghorn: No, believe me, we have tried, we've looked at lots of different options. It's the same across the globe in the airline industry. They spray anti-icer on, which gives them a hold over time. So while they're on the stand, they're sprayed, that allows them to sit on the stand and then they can be there for a couple of hours before they push back for takeoff.
[00:04:17] Ian Waghorn: So, we do try to intercept about 20 to 30% of that by using sweepers. So when the aircraft pushes back off the stand, sweepers come in and collect as much of the deicer that's fallen as we can. So we do actually take that out of the system where we can, but inevitably some of that deicer will enter the drains.
[00:04:37] Piers Clark: Okay, so you've gathered up the deicer fluid. You've got some of it trickling into your collection tanks, some of it's gone into the sewer network. What happens? Does it break down biologically or how do you destroy it?
[00:04:49] Ian Waghorn: Those deicers are completely biodegradable, so they don't have any long term effect as pollutants. However, it's that biodegradability that is the problem because they've got very high BOD and COD demands.
[00:05:03] Ian Waghorn: So if they go into the river, worst case scenario would be the river going eutrophic, but the normal cases that you would get sewage fungus forming downstream of discharges if you don't manage the process.
[00:05:17] Piers Clark: What do you do with it? How do you destroy it?
[00:05:19] Ian Waghorn: So basically when we detect that deicer, rather than discharge it into the river, we pump all of that three kilometers down the road to the Thames Water Sewage Treatment Works for processing. The problem being that we pump it over at 400 liters a second, they can only treat about 60 liters a second. So there's a bit of a mismatch there. So in between those two processes, we have these huge reservoirs, 320,000 cubic meters of storage, which basically is allowing us to keep pumping over throughout the whole winter season and gradually allow Thames to treat the water in a way that ensures that none of that deicer ends up out in the river.
[00:06:02] Piers Clark: And does Thames have to do anything special to treat it or does it go through conventional treatment processes?
[00:06:07] Ian Waghorn: It just gets added to the conventional sewage that's coming from the local town, Crawley. It's just a very small addition to the normal biological treatment that sewage treatment works is providing.
[00:06:19] Piers Clark: Nice. Okay, Ian, Ian I get it. You gather it up, you send it down the road to Thames Water.
[00:06:24] Piers Clark: Any problems with that process?
[00:06:26] Ian Waghorn: Most of the time that works fine. We end up getting to February-March time of the year. Both lagoons are then getting pretty much full to the top working level. So then I start getting very nervous because once we get to that point, there's nowhere else I can send that polluted water to. So we avoid that scenario and we always make sure that first flush of really concentrated stuff is always pumped over for treatment.
[00:06:55] Piers Clark: Excellent. Now, I wanna hear what improvements you're doing, but before we do that, let's just have 30 seconds on the decade of change. What is Gatwick Airport's decade of change?
[00:07:08] Ian Waghorn: So the decade of change is 10 sustainability goals across the whole airport. My one is goal eight, which is water. First thing is to half our potable water usage. The second is to improve the water quality leaving the airport, and the third is to work with partners to improve the water environment in the whole catchment.
[00:07:28] Piers Clark: What I love about the decade of change, I know this is my words, it is about making Gatwick one of the greenest, most sustainable airports in the world, I think is how it's presented, it's how it feels. It's aspiring to reaching beyond where a traditional airport should get to, which is very impressive.
[00:07:46] Piers Clark: Now, we are going to revisit that halving of the potable water in a few minutes time. But let's come back now to the deicer fluid and what you are going to do in the future as part of your decade of change?
[00:07:56] Ian Waghorn: The bottleneck that we experience is the fact that Thames can only process that 65 liters a second. So we came up with the idea why don't we build our own treatment system?
[00:08:07] Ian Waghorn: We looked at shall we say the big brother airport up the road from us at Heathrow. We looked at MBBR treatment, which they have, but we also looked at their reed bed system. And we planned for that because the reed system has so many additional benefits, biodiversity, net gain, that kind of stuff, which we're really keen on.
[00:08:27] Ian Waghorn: So that's what we've planned for. We are gonna build our own reed bed treatment system. We've modeled the pollution and we believe that will then entirely cope with all but the really severest winters in the future.
[00:08:40] Piers Clark: I do love this idea of a modern airport utilizing technology that is as simple as reed beds. There's this beautiful dichotomy, it feels to me.
[00:08:50] Piers Clark: Okay Ian, you mentioned as part of that decade of change that you are looking to halve the amount of public water use. You've got 40 million visitors coming through Gatwick Airport.
[00:09:01] Piers Clark: How are you going to persuade them to use half as much water? Everyone goes on holiday and they're not interested in saving water. That's not at the front of their minds.
[00:09:11] Ian Waghorn: I did, first of all, propose maybe we could just remove all of the toilets but apparently that wouldn't meet customer expectations.
[00:09:19] Ian Waghorn: No, in all seriousness, I think it's worth mentioning that in our previous decade of change, 2010 to 2020, we already halved our potable water usage from 30 liters per passenger down to 15 liters per passenger. So in this next decade of change, we've got half it again, and if you think about it, seven and a half liters is roughly how much you use if you flush a toilet.
[00:09:42] Ian Waghorn: So, instead of people using potable water to flush those toilets, if we could give them another source of water to flush those toilets, then that pretty much halves the portable water usage.
[00:09:54] Piers Clark: You are gonna tell me you are using the deicer fluid in the toilets now, aren't you?
[00:09:58] Ian Waghorn: Exactly. That's exactly what we're gonna do. So after the water has been treated by the reed bed, we will get the water back into the airport and then pump it up into the buildings. We will have to do like a secondary treatment system, bit like a rainwater harvesting system. And it's quite interesting the legislation and technology around rainwater harvesting, graywater harvesting, and blackwater harvesting.
[00:10:22] Ian Waghorn: So we will do this secondary treatment in all of our buildings and then use that water for flushing toilets and flushing urinals. And we believe that if we do that, we're definitely well on our way to achieving that 50% target.
[00:10:36] Piers Clark: And of course there's an added cost with all the extra plumbing, but because you control the building design, that dual plumbing system for the reused water should be relatively straightforward?
[00:10:48] Ian Waghorn: It should be because really it's only adding an additional pipe, some additional tanks, separating the two systems because we've been thinking about either rainwater harvesting or other ways of reducing potable water usage.
[00:11:01] Piers Clark: Good. And tell me the timeline. When are you hoping to have this in place?
[00:11:06] Ian Waghorn: The target is to have it all achieved by 2030, so we haven't got long left to achieve that so we're gonna have to get our skates on.
[00:11:11] Piers Clark: Brilliant. And its 2026 now I wish you the best with that.
[00:11:16] Piers Clark: Now, we talked about the wastewater and surface water management. We've talked about the potable reuse of the 40 million customers. What else is in your plans?
[00:11:26] Ian Waghorn: Probably one of our biggest risks at the airport is flood risk. As you mentioned earlier, we're in a flood risk area. A flat area where rivers meet, perfect for putting a runway in but not so good if you're trying to manage the flood risk.
[00:11:42] Ian Waghorn: We have already done a huge amount of work in previous years with the Environment Agency, with the upper Mole flood alleviation schemes. We've invested in our own 12 million pounds flood alleviation scheme just upstream of the airport. And in the future, we are looking at further innovations to protect the airport as well as we can.
[00:12:02] Ian Waghorn: A lot of it now though is getting into the realms of what I would call climate change adaptation. So it's actually, okay, let's look at the infrastructure, let's see what we can raise above the flood level.
[00:12:14] Ian Waghorn: You can't really ignore climate change. It's something even in the short time I've been doing this role, you can see the weather events are getting more and more serious as the years go on.
[00:12:25] Piers Clark: Excellent. Ian, thank you for sharing that with us. I wish you the very best with the rest of the decade.
[00:12:30] Piers Clark: Now, we always finish with a couple of cheeky questions. And the one I'm going to ask you is, I want you to go back 30 years at the very start of your career. And what advice would you give a young Ian Waghorn then?
[00:12:45] Ian Waghorn: I'll probably say to myself, just follow your instincts. Follow your heart and your gut if you like and don't underestimate what you might be able to achieve. Don't listen to that inner critic too much. Don't talk yourself out of things.
[00:12:58] Piers Clark: You have been listening to the Exec Exchange with me Piers Clark, and my guest today has been Ian Waghorn, the 'Waterman' at Gatwick Airport, and we've been talking about how you run the water assets on a modern airport.
[00:13:12] Piers Clark: Hope you can join us next time. Thank you.