Where asphalt and concrete reign, the soil under our feet isn’t always front of mind. Yet millions of tons of soil underpin the five boroughs of New York City, supporting the foundations of buildings, filling parks and community gardens, and covering up decades of industrial contamination. This matrix of soil, which extends into the city’s harbor and lines its rivers and estuaries, is entangled with life above ground: filtering the air we breathe, holding traces of the past, and contributing to fundamental ecological processes. The biology of human life quite simply hinges on soil’s existence.
The stakes of effective soil management could not be higher in a region where earth is being mined, dredged, shifted, and dumped on a massive scale. While New York City has plenty of soil, much of it has ingested legions of toxins: pesticides, heavy metals, and gasoline residues are mixed up with decades of construction debris, as well as new and lesser-known contaminants. The demand for uncontaminated soil stretches across state borders. Over the coming year, for instance, approximately 100,000 cubic yards of soil — mined in part from the Ambrose Channel in the lower New York Bay — will be used to cover Freshkills Park on Staten Island, formerly the city’s most notorious garbage pit; the remainder will come from New Jersey and development sites in Queens. Moving fresh material is expensive and requires a fleet of carbon-intensive barges and trucks. Transfer stations are often located in environmental justice communities.
While the supply of soil itself is limited, opportunities for New Yorkers to understand soils, and their environmental, cultural, and social value to the city, are expanding. The Urban Soils Institute (USI) is seeking to change the way we view soil by providing an open platform for the public to educate themselves about soil’s life-giving properties. Co-founded five years ago by geologist-turned-soil-expert Tatiana Morin — whose life motto is: “Take care of your own shit” — the Institute combines research, technical services, and educational programming. Here, she talks about USI’s efforts to push urban soils knowledge outside the domain of science and into the hands of communities, and to bring innovation into managing the city’s legacy of toxicity.
Can you tell us about soil in New York City? What sets it apart?
New York has been a conveyor belt of real estate development and redevelopment. So much dredging has happened, and that dredge has then been used for fill. A lot of the sediment removal for construction in the city would end up at the edge of the continental shelf. There’s been a kind of exchange of soils between the sea and the land. A lot of the time, all this construction debris — bricks, glass, metals, paint (which can contain heavy metals) and concrete — has no place to go. It just gets smushed in with the next project, and then the next project. That really changes the chemistry of the soils.
They’re very heterogeneous. I remember we partnered with a nonprofit and an environmental engineering firm to restore a vacant lot in Harlem, which wasn’t that big; we tried to create a green space for the community, with a native wetland and native plants. Each pocket required us to treat the soil a little bit differently. One was completely compacted, the other was completely sandy; then another spot was just full of ash and slag (the greasy, glassy leftover from smelting).
When you have a lot of vacant land and parks where the chemistry of the soil has been so heavily changed, multiple methods are needed to improve the soil so that it can support the native ecosystem. Soil chemistry is affected not only by construction debris, but atmospheric depositions, contamination, and the moving and mixing of soils from different areas. Heavy metals, like lead, arsenic, and mercury, as well as organic contaminants — which aren’t often tested for because the process is expensive — become airborne with dust and then get re-transported. So there’s a very heavy retrofit needed to bring soils back to what they really should be for their geographic and climate area.
Could you talk about what makes a soil urban?
Urban soils are kind of like everything we know about soils, and then some — because we got involved! The anthropogenic impact is just that much stronger. There are parts of a city where we get as close to native soils as we can — soils that have been undisturbed for hundreds of years — but you also have your humanly impacted soils, the ones that have been degraded or transferred or formed or altered in some way by us.
There are engineered or constructed soils, as well as unintentionally constructed soils. For example, in a community garden where someone’s brought in soil to put on top of the existing soil, you could call that an intentionally constructed soil, because someone is trying to mend something. You could also think about a technosol: a soil type developed because of urban influences over time. A new soil has formed like a new baby. Or you could think about urban soil as an engineered soil that’s been very intentionally made: reusing waste products or materials like vermiculite, crushed bricks, or glass, to mimic a natural soil, but tweaking them to behave and function better for specific city applications like stormwater management, heat island mitigation, or green roofs.
It’s not soil, it’s soils. Because, just like people, there are so many different kinds of soils out there. While soils could be defined by any mineral material that’s been weathered from rock — that has life living in it, and the potential to support more life — I think our definition is limited by our lack of imagination, knowledge, and realization that we have so much more yet to discover.
What does the Urban Soils Institute do?
We had the ambitious plan from the very beginning to be a platform. It’s a place where everybody has an opportunity equal to everyone else to be part of the world of soils: to participate, learn, discover, share experiences, get resources, and collaborate holistically with various backgrounds and disciplines. We are a platform for the people by the people. It’s got to be both.
In the beginning, we offered technical services, which means if someone needed us to come on site to assess their area (be it a garden, playground, backyard), to understand what to do or how to even start with soils, we could do that by offering soil testing. We knew that education would be the most important piece of it all — giving people the access points to understand soils from whatever perspective they needed to do that from, and then let people know that there is an opportunity for communication, a back-and-forth. We hold a lot of workshops.
And we also do research, so that we can be the go-to place for people to ask, “Hey, what is the latest threshold for lead, and why is it that?” We aim to be like a Reader’s Digest, so people know what scientists know and what scientists don’t know, because soils do not belong in the science realm only. It’s so easy to say, “Well, the scientists should know that,” or “We’ll wait for the scientists to understand this.” But many times, scientists need feedback from other disciplines, other people, to understand soils as a whole.
We want to give people tools so that they can understand soils for themselves and make their own decisions. That way, you wouldn’t need so much heavy regulation of a common resource. I’m not against regulating. But we shouldn’t be premature about it. We need to first give people the opportunity to learn the basics so that they can make their own decisions. If they want to really grow their garden, and they’ve understood a soil and how to work with it, give them the freedom to do that.
Some contaminants will never go away. But if you can work with them, and keep them abated, then there’s no risk issue; though that has to develop with some understanding. That is the approach we take in a lot of the work that we do. We’re not one of those cap-or-remove or “just do it safe” organizations. I don’t believe in that. What underlies all of our work is giving people the knowledge that nature restores itself, always.
Can you tell us about the Institute’s annual symposia?
When we started, it was just, “Let’s have an open house and talk about soils.” We had artists there, and scientists, and government people. I didn’t expect people to come up to us and be like, “We’ve never been on a platform before where we can talk to all these different people from different backgrounds in the same room.” And most of the surprise came from the city and government agencies. That this model is needed and useful is awesome. I thought we were going to be this local, itty-bitty entity, but that doesn’t make sense if you think about it. We don’t have all the urban soils answers. We’ve got such great collaborators and connections overseas. You need to be connected to everybody else who’s doing work on urban soils.
Having artists at our symposia helps lift the platform and make it more accessible. This year, we had some people bring in different perspectives, including from economics, cultural and religion. We just try to keep opening that holistic, interdisciplinary approach.
What are some other projects you are working on?
We’re trying to work on a soil museum, which we’ve nicknamed “Soiled.” It’s “soil” and “ed”: soil education. We want to be able to show the nuances of soil. You could start by introducing yourself to the physical being of soil: the smell, the touch of it, the texture, the different colors, what’s living in it, its heartbeat. And then we want to show it from a very scientific perspective, whether that’s a soil scan, a leachate, or making soil stains. It’s also extremely beautiful. So much can be learned through observation, and colors mean a lot.
We also want people to understand all the cultural and philosophical aspects of soils. Soils can mean home, safety, familiarity. In times of war, soils can keep the memories of those tumultuous, horrific experiences. Soils hold a lot of things symbolically.
What are we missing when we only focus on science?
Because soils are a common resource, like water and air, they tend to fall into the scientific realm. If you learned about them, you had to be a scientist. And I think that’s a little bit of a mistake — or should I be bold and say, “a big mistake”? — because it’s like saying: You have your own body, you can walk around in it, but in order to understand it, you have to go to medical school. That’s just silly, because this is a fundamental, life-giving resource. You can understand a heck of a lot about it without understanding the geochemistry.
On the whole, there is so much you can learn if you approach soils from an artistic or cultural perspective, or even a religious or spiritual perspective. The specifics of your understandings are going to be different, but your general understanding and ability to work with them would be the same.
Without a platform for people to understand soil, so many will avoid it and then end up making costly decisions, or won’t be able to grow a garden because somebody, some scientist, scared them off. We need to make sure that people feel like they have the ability to glean knowledge, and love and respect soils — that it’s a relationship that develops over time.
In terms of understanding natural soils and agricultural soils, soil science has gone very far. But urban soils are the new frontier, or the last frontier, of soil science. The soil frontier is literally new because when you disturb a natural soil — whether that means you’ve dumped toxins into it, or you’ve moved it and replaced it, and tried to grow something again — it puts a stick in the wheel. Now everything’s topsy-turvy. Nature is extremely resilient and will always try to restore itself and become better. We have a lot to learn about soil’s capacity to self-remediate; but at the same time, we have a lot to learn about all of its capacities to fulfill certain ecosystem functions that we need, or to be able to serve a different purpose for human infrastructure that we need.
You mentioned that we can now engineer soils. How does this help cities?
Some say it takes 500 years or more for a soil to form. You cannot create a soil anywhere near as good as this 500-year-old soil. There is an argument, however, that rather than just focusing on restoring degraded soils around the world, perhaps we can create them to rejuvenate our urban centers on a much faster timescale. Why can’t we offset the damage that we have already done and create soils that are actually functional in cities, and then keep restoring and rebuilding what we already have and what we’ve lost? It will come to some kind of balance.
There are some purists who are like, “What are you talking about?” I, too, would love everything to be in its purest state, never to have been contaminated. That’s not realistic. Do we deny our cities this opportunity to make up for some of the mistakes we’ve made, to become greener, and to let people garden? I’m not saying that we forget about those soils we’re destroying; we must conserve and be proactive in conserving what we have left of our native soils. But in addition to this, I have hopes for reusing waste products to recreate soils in cities to support biodiversity. I think this is important. We’re mining soils from somewhere else and then importing them to the cities. That’s not a good solution. That’s not a better option than saying, “Hey, we have the option of remediating soils,” or, “We have an opportunity for creating a soil here, maybe even from some waste products.”
What does the future of urban soils look like?
Soil scientist Jean Louis Morel does great things. He mines contaminated soils for various elements, or for different metals, and then reuses them in different products. But also, with his colleagues, he was able to restore a contaminated industrial site by rebuilding soils using waste materials — like paper, pulp, bricks, and things like that — to mimic the natural soil. They used this new soil to softly “cap” the contaminated soil underneath. They’ve been able to bring back the biodiversity of the area, and have been watching the soil basically clean itself and develop and function like a natural soil.
This was done on a time scale that’s important for urban areas. Before, you either had to go in there and heat the place, or vaporize it, or do something quickly so that construction could start immediately.
As for us, we’re going to create soil mixes with different waste and compost products that we’re allowed to use. Then, I think we will work on researching waste products that we are not allowed to use. In New York City, it is still against the law to reuse certain waste products like construction debris and concrete. But what if we could reuse a lot of common waste products in urban areas? Old bricks that are being thrown away could be the clay component; the glass aggregate could be part of your mineral component. The idea would be to mimic nature’s recipe for a particular soil, and then see how long it takes to function like a native soil. Can it support the same kind of forest? Can it infiltrate as much water? Can it clean the air around it? We don’t have to wait 500 years.
The views expressed here are those of the authors only and do not reflect the position of The Architectural League of New York.