The Future of Sanitary Engineering

GURU MADHAVAN

The early Bronze Age. Mohenjo Daru, or the Mound of the Dead, was the centre of the Harappan culture in northwest India. The ruined remains of the Indus Valley indicate that this advanced civilisation was developed between 3300 and 2700 BCE. My ancestors engineered this metal age metropolis. Every house in Mohenjo Daru had a washroom and water-based latrine. Water was supplied from hundreds of wells and waste was conveyed to an extensive sewer system by slopes and tapered terracotta tubes to settling stumps that reduced clogs. The streets ran north and south, east and west, and houses were built with well-burned bricks made from a standard system of weights and measures. While little is known about my ancestors, we can learn a lot from the sweeping social vision for sanitation that we see in modern-day New York. “The sewer is the rendezvous of all exhaustions, even a city's conscience,” wrote Victor Hugo. “A sewer tells the truth. There are no lies or secrets, only confessions.”

I am Guru Madhavan and in this episode of Create the Future, we will explore the secrets of sanitation, how we make elixir out of excrement, and why such profound processes of care and maintenance deserve our deeper gratitude. My guests are Pam Elardo, a health and environmental protection engineer who led New York City's Bureau of Wastewater Treatment and is now with Brown and Caldwell. And Andrew Russell, a historian of technology and business from the State University of New York Polytechnic Institute. We will look at how sanitation engineering has transformed our lives and livelihood.

PAM ELARDO

I didn't think twice about the fact I could turn a tap on and get drinkable water. And I didn't think twice about the plethora of waste that's collected in my neighbourhood and wondering where it's going to go.

GURU MADHAVAN

Why such acts of caretaking are often neglected and overlooked.

ANDREW RUSSELL

There exists within our modern world all of these systems that are hidden to most of us every day that allow us to just go about our daily lives.

GURU MADHAVAN

And why we need to prioritise maintenance to unlock new futures for innovation.

PAM ELARDO

People coming out of engineering school, they want stronger meaning for their work and they are interested in their impact.

GURU MADHAVAN

Pam and Andy, welcome to Create the Future. Pam, let's start with you. Most people finish their business by flushing the toilet, but that's when your business begins. You led the largest municipal wastewater utility in North America. Please take us through the mysteries of how sanitation engineering works in New York City.

PAM ELARDO

Hey, well, thank you for asking that question. Sanitation works in New York City like it does in many cities - or in places where it doesn't work well, it is the goal for other cities to manage their waste in such a way. But typically a wastewater professional does start when people flush. Unfortunately, when people flush, they think that's the end, it's taken away. My mission in life is to let people know that is not the end and to appreciate all that happens subsequent to the flush. There are mechanical, physical, chemical, and biological processes that come in play to make sure that your waste does not contaminate waterways, it does not spread disease, it does not cause problems for your neighbours and for your community and for the aquatic life that surrounds you and the water supply that you rely on to stay healthy. So, overall, you can't ignore that value. So to begin with, there's a network of collection pipes that come from every home into the streets that go into larger interceptor pipes that then ultimately go to treatment plants. In the old days, before we knew that we needed to treat the water, we just built pipes to take it away. I think the first level of human consciousness about the problems with waste emerged once people started to live in concentrated settings. You know, when the population is dispersed and your personal poo can go in the fields, it can go across the street, it didn't really matter. But when people started to live in groups and ultimately we discovered that there are diseases related to faecal contamination to humans, we had to get it away. So that was the collection systems and that worked great. Just put it to the nearest water body, right? Eventually people realised, well, the receiving waters, the waters that we rely on to either drink or navigate, aren't an endless resource that we could just contaminate. So we started to build treatment plants. And the first treatment plants were basically sedimentation basins that separated out what I like to call the floaters and the sinkers. The sinkers would be materials that sink, and the floaters is grease, oils, and everything in between. And so the first plants did that. It removed about 60% of the contaminants and added disinfection, which was really a breakthrough to create a cleaner effluent. The original treatment plants in New York City in the late 1800s were all targeted towards public beaches. People were unable to recreate at public beaches. The initial wastewater treatment in the Seattle metropolitan area came from the contamination of Lake Washington that had to be closed to public contact. So these realisations started to emerge and then that physical separation process was the first. And later, more techniques for refinements of the treatment process therefore includes a biological process that takes the water from the primary treatment and uses a community of bacteria to break it down further. What we basically do at a treatment plant is speed up the process of natural systems. When a bear poops in the woods, that poop is surrounded by air, it's surrounded by bacteria in the soil, it's surrounded by insect community, and within a certain period of time, depending on whether they're in an arid climate or a wet climate or dry or cold or warm, that turns into fertiliser over time. And that's the reason why we have life, that cycle of life is based on that fertiliser cycle. So we take that thing, that process that takes weeks or even months maybe depending on conditions and speed it up into a couple hours resident time in a treatment plant. So we create that biological system, which is a series of tanks with the right conditions for the right biology to break down the waste to create clean water. After that biological process, there's further separation. Again, there's disinfection. And then the solids, which are that active bacteria, are pulled off, reused in the system because we need to keep the biology alive and then waste in the excess bacteria goes to a further solid treating process, which amazingly works like your stomach through anaerobic digestion and creates a fertiliser product that's called biosolids and also can create green energy. In an anaerobic system, we're using a different set of anaerobic bacteria to create a green bio-gas, which offsets the use of fossil fuels. It's used actively in New York City and elsewhere to inject into pipelines so that it's actually going to people's homes for heating and cooking.

GURU MADHAVAN

Some years ago, the British Medical Journal reported that the public protection enabled by sanitation engineering had been the most significant medical advance, followed by achievements in antibiotics, anaesthesia, vaccines, imaging, and genetics. Andy, could you take us back into the history here?

ANDREW RUSSELL

Yeah, it's pretty astonishing what people have been able to devise to elevate human flourishing and human thriving. And of course, the first step there is survival. And as Pam indicated, this is not something that could be taken for granted in the past. When people came together in groups in some key areas in the world, whether it's the Indus Valley, Mesopotamia, and later in South America and Europe, we're familiar when we learn world history about wars and conflicts. We are somewhat less familiar, especially those of us raised in the West, with the heroic efforts made in areas to sustain human life, whether it's in agriculture or in sanitation, and in later centuries communication and information. So I see the developments in the ancient world and, you know, times in the BCE era as architectural marvels, as well as marvels in human health to facilitate human flourishing, as well as marvels in social interactions and ways that people found ways to get together and enact whether it's structures or organizations or just ways of being that could make life better not only for themselves as individuals but as part of their groups and to extend that over time. So many of those structures persist. Some people might be familiar with them in Western Europe but it's really ancient people from further east that were real pioneers.

GURU MADHAVAN

Sanitation is embedded in the origins of public health, a practice founded by engineers rather than clinicians. In what ways do you think sanitation has fundamentally influenced our culture?

PAM ELARDO

First and foremost, working in the wastewater business, we are public health practitioners. That is absolutely true. So my personal experience and exposure is coming from a developed place in the world where I didn't think twice about the fact I could turn a tap on and get drinkable water. And I didn't think twice about worrying about the plethora of waste that's collected in my neighbourhood and wondering where it's going to go. Right after college with my environmental and chemical engineering degrees, I went to Peace Corps, which is an American volunteer service. And overseas, what I did was build water systems and toilets essentially in remote areas of Nepal. I had literally never left the United States before in my life. I was very young and very green. So I, you know, learned enough of the language to be functional in a remote setting. And I started to build, design and build, community water systems, which for the most part were gravity fed systems from taps, you know, tapping into a spring up the hill, and this is Nepal, so you had the luxury of a lot of gravity, piping those systems of clean water, protecting the source, piping this clean water into where people lived, one tap stand for every eight to 10 houses. So I saw first-hand what happens when people don't have sanitation. It's heart-wrenching. Anytime a group of women got together, and men too, ultimately, they would talk about how many children they lost, at what age. So infant mortality is a real thing. I saw children who were suffering from dysentery. I took a friend's child to a hospital with her to try and save her life. And that's a living reality still for many people in the world. So fast forward to where we live. Right now, I'm in New York City. I lived most of my life in Seattle. I don't think about that. I don't hear people talk about infant mortality as something that's common, but we got into a place where it's taken for granted. And imagine not having it. I want people to imagine it. I think it is a responsibility for every citizen who flushes to go visit a treatment plant and understand the complexity, the dedication of the men and women who do this 24-7 without disrupting service, without causing havoc in your neighbourhood. We only get called out when something goes bad. But the fact that 99.99% of the time, there is zero disruption of your service and you've had the luxury of not thinking about it.

ANDREW RUSSELL

I think there's two ways to think about how sanitation has influenced culture. One is on the level of systems, as we've talked about. There exists within our modern world all of these systems that are hidden to most of us every day that allow us to just go about our daily lives. There's some economics and engineering aspects of those infrastructures that are fascinating. And in recent years, I think getting more attention from the public and a greater understanding that infrastructure matters, infrastructure workers matter. Recently, we've taken to calling them essential workers. And so on a societal wide systematic level, some of those dynamics are quite clear. The other part that your question brings to mind for me is individual aspects. And I think about this through time. And so just thinking about the aesthetics of cleanliness for individuals, which is not a cultural value that is inherent in our DNA. It's something that different societies have learned over time. There are deep connections there to modern capitalist enterprise. There is a giant industry with some of the wealthiest corporations in the world that produce the chemicals and the fluids and the shampoos and the aftershaves and the deodorants, all of the things that go into individual sanitation. And this industry or these companies have all the hallmarks of modern capitalist industry. They cater to our preferences for convenience and for bringing out individuality in whatever ways it is. These days, if you go through a middle school or high school or walk the halls of a college campus, you realise it's smells. And there's a large, large industry behind there too. So when I think about sanitation and culture, I think not only about the systems, but also about individuals.

GURU MADHAVAN

Now I want you to help us imagine an absence. What would the world be like without maintenance? And why is maintenance hardly celebrated in society?

ANDREW RUSSELL

So the one word answer to your question is collapse. A world without maintenance is a world that would collapse because if you think of any structure, if you think of any activity, that activity or that structure in the absence of maintenance is the eventual victory of the second law of thermodynamics, which is entropy. All things will just disperse of their own accord. Maintenance is the bulwark between civilization and collapse. So that said, why do the maintainers not get celebrated as the saviours of humankind? And in my view, there are some cultural and some biological or bio-psycho answers to these questions. So the cultural just has to do with what cultures choose to prioritise. It varies over time and over place. So in contemporary American culture, there is a preference for novelty, for invention. It's embedded not only within the arts, but it's embedded within our technological civilisation. People are on the front foot to know what's next. And there's a certain restlessness in American culture that feeds into that. The flip side of that is that, you know, if there's only so much time in the day, only so many heroes to celebrate, we tend to celebrate those that are doing what's new and what's next. The psychological element there is that it's just easier and perhaps natural from an evolutionary standpoint to take things for granted.

PAM ELARDO

Imagine a world without maintenance? I've gotten tastes of that in my past because there's only so many dollars to keep up repair and replacement and renewal cycles so that we do have to make some hard decisions often in the wastewater and infrastructure and public infrastructure world. My job has been focused on preventing disruptions, 100% of my job. Preventing disruptions also means looking to new and innovating and surviving with using new technology, but preventing disruptions foundationally means caring for what you have. Enabling innovation requires a strict adherence to maintenance, obviously. So a world without maintenance means there isn't the availability to continue the kind of service we provide. There isn't the availability to take it for granted because you will see lots of things falling apart. There are heroes out there who are maintaining systems on a regular basis. The same people become superheroes when there's an emergency and they have to address it. So my gig for the last couple of decades has been making less emergencies and more regular maintenance and employing reliability-centred maintenance techniques to optimise our use of data in that. And furthermore, taking reliability-centred design, which is where you take the maintainers and the operators, and they are actually informing the upfront design. And that is a higher level of reliability-centred focus and creating the best systems that can be operated through what operators' and maintainers' knowledge can bring and what they need in the field and how to make their jobs much more efficient.

GURU MADHAVAN

Since you both talked about heroes, it reminds me of what the novelist David Foster Wallace observed. “Actual heroism receives no ovation, entertains no one. No one queues up to see it. No one is interested.” So how do we stimulate a greater appreciation for sanitation engineering and maintenance?

PAM ELARDO

I've really changed my ethos and my drive from being an engineer who solves water and sanitation problems to being a leader in our field and applying systems engineering thinking actually to create community assets in our sanitation infrastructure. Researchers, there's one particularly at Columbia University, he calls a wastewater treatment plant a biorefinery, it is a place where we can create biologically carbon neutrality based products. And we're already doing that. We're creating a biogenic fertilizer. We're creating green gasses. We're generating electricity from the wastewater system. We are putting carbon back into the soil. There even is a lot of research on other products we can pull off what is the waste stream into being a positive. There's an economic circular economy that we drive. But at the same time, we're in every community. There's pump stations everywhere. There's treatment plants that serve communities. They need to be positive assets. On top of that, it is an engine for equity. We have every single kind of profession in the field of sanitation. There's artists actually way beyond just engineering that we could really bring the next generation of people to really grow their economy, their personal economy, and contribute to our community in ways that I think we have just started to explore.

ANDREW RUSSELL

This is easy. Take four major institutions. The UN, The White House, pick a bank, and Parliament. Make them all stay in their building for a week. At the beginning, tell them the costs of their sanitation, including the wages of their workers. Then, turn it all off. Send the workers on vacation for a week. Then at the end, ask everyone in those buildings if they think the numbers they were given at the beginning are the right numbers.

GURU MADHAVAN

What are you both optimistic about the future of sanitation and maintenance?

ANDREW RUSSELL

Two things give me optimism. The first is the energy of the activists who are pointing out problems in sanitation. I'm thinking in particular of Catherine Coleman Flowers, MacArthur Prize winner, who has done tremendous work in advocating for rural sanitation in parts of the United States. I think that energy and effort has been mirrored elsewhere in the world, and that gives me some cause for optimism. The second thing is that technology continues to advance and there's very clever people working in the world of sanitation that are applying techniques, whether it's from sensors or new approaches to machinery, new ways of measuring flows and new ways of thinking through problems of accounting, for example, that can really help to move the needle from where sanitation is now to where it can be in the future.

PAM ELARDO

My optimism is a little bit related to what I talked about in terms of becoming community assets, but really we're on a precipice of a lot of different things. Access to digital solutions is extremely helpful. I work now for an engineering company that's been around for 75 years. And our purpose is to unlock the potential of water to create a healthy environment and create thriving communities. So that is a holistic view. The next generation of engineers that we are bringing in are much more integrated. They have a growing awareness of the importance of the work that we do, and they bring new tools and new perspectives, particularly with some of these entrenched, very difficult, wicked problems in the world today in terms of environmental quality. That holistic view is stronger than ever, and I believe we can take it to better outcomes for communities at large.

GURU MADHAVAN

In engineering caregiving is all too often invisible. It doesn't appear in financial statements, nor are there market incentives, nor do we get bonuses. But sanitation makes it clear that engineers, much like nurses, are professional care providers for this world. Is this a radical thought?

PAM ELARDO

Honestly, I think it's becoming less of a radical thought. You know, even in my short career, the things we're talking about today we would have never talked about earlier. The idea that there are stakeholders beyond the piece of infrastructure we're providing and then there are end users as well as community concerns and community insights, that was radical. But today's society won't let that stand anymore. And we're realising that quickly. Pro-social forms of engineering is resonating. And I talked earlier about the current generation of people coming out of engineering school, they want stronger meaning for their work and they are interested in their impact. They grew up in a different world than we did. It's much more connected and they're much more aware of the value of what diversity brings and they know it makes better projects and they know it makes organisations better. And I think it is not radical at all. And I appreciate that we're all coming to that conclusion much more broadly than ever.

ANDREW RUSSELL

I don't think this is a radical thought. Let me explain where I'm coming from. In my day job, I am the Provost at SUNY Polytechnic Institute and a lot of our programs here on campus are engineering programs. So engineering education is a big part of what I think about and what I do on a daily basis. And what I've observed both in my own scholarship as well as in programs and students that I observe here on campus is that the impulse for what we're calling humanitarian engineering - that is engineering focused on projects that benefit society, you know, such as projects for assistive devices, clean energy, circular economy - those are the projects that the students are really passionate about. Those are the projects that the faculty are really excited about. Those are the projects that our industry partners are really excited about. And so when they hire our students, that really resonates with the partners and that energy infuses the workplaces that they go into, whether it's Department of Transportation or semiconductor companies that we have here locally, whatever it might be. So it is really the key, I think, to unlocking the passion that's deep within all of us to know that the work that we're doing, we're not just going through the motions, but we're really making the world a better place. We're really making our workplaces, our products, our processes, the sorts of things that reflect the care that is deep inside all of us.

GURU MADHAVAN

As artificial intelligence grips our world, sanitation engineering is a story of the other AI, ancient intelligence. The Indus Valley, with its sophisticated food production, grid town planning, drains, dams, and dockyards, was a testament not merely to civil engineering, but to a form of civic engineering. They improved both standards of living and thinking. And we need such cultural consciousness to better care for the past, the present, and the future.

Thanks for listening to Create the Future, a podcast from the Queen Elizabeth Prize for Engineering and Peanut & Crumb. Look out for new episodes every two weeks and follow QEPrize on social channels, Instagram, Facebook and X. This show was produced by Tess Davidson. And until next time, this is your host, Guru Madhavan.