City of Soil: A Walk Down Stratford Avenue with Paul Mankiewicz

Paul MankiewiczPaul Mankiewicz is no ordinary biologist and plant scientist. As founder and director of the The Gaia Institute, Mankiewicz explores — through research, development, design, and education — the relationship between human communities and natural systems. Resting on the dual hypotheses that the flow of “waste” materials from human activities can be cleaned and utilized to support habitat, and that human industry can be coupled with conserving and creating landscapes for everything from birds to bacteria, Mankiewicz’s essential philosophy holds that humans and natural systems can coexist to mutual benefit. The Gaia Institute implements a variety of projects for both public and private clients throughout the five boroughs, including: green roofs, urban farms, watershed restoration, stormwater treatment, and other forms of ecological engineering. Many of the institute’s projects utilize GaiaSoil, the lightweight soil that Mankiewicz has developed and distributes.

Earlier this month, I met Mankiewicz on Stratford Avenue in a south-central section of the Bronx where he is about halfway through retrofitting eight existing tree pits with curbside drains, expanded tree beds, and new combinations of plants. Each of the enhanced curbside swales will capture roughly five thousand gallons of water over the course of a strong storm; polluted water that would otherwise find its way into the city’s oversaturated system and cause a combined sewer overflow to drain directly into the Bronx River. Mankiewicz’s interventions are not overly complex — here they consist of a two-foot gap in the curb, leading to an enlarged bed of soil below grade — but in the case of Stratford Avenue, they are designed to handle the stormwater produced by a 100-year storm. Mankiewicz took some time out of his day to talk to us about GaiaSoil, the inherent environmental productivity of organisms, his infrastructural advice for our coasts post-Sandy, and to explain why the city’s waste stream is our greatest untapped ecological and economic asset.


How do you explain the Gaia Hypothesis to someone unfamiliar with it?
The best way to describe it is that organisms are fundamental regulators of conditions on the planet; they modify the atmosphere and, to some degree, the oceans, so that the temperature stays within certain bounds. Over the past three and a half billion years, the sun has gotten hotter and more radiation has come into the planet, but — recent climate change not withstanding — the earth has stayed around the same temperature. That’s puzzling to physicists. The Gaia Hypothesis attempts to address that paradox.

How does this hypothesis differ from more traditional systems ecology?
The Gaia Hypothesis provides a different ecological ground than standard ecology. It’s not so much about balance and equilibrium, although it can be described that way. Rather, it’s about conditions that make it possible for all life to not only survive, but to prevail. Evolution is a process driven by disequilibrium. Teams of organisms are fragile; if you push them too far in one direction, they’ll die. And if you push them too far in another direction, certain organisms will take over. But new organisms are always being selected that are able to do things better or in a more integrated way. For example, the beaver might seem poor for an ecosystem because it cuts down trees. But beavers create ponds, and those ponds increase biodiversity and store carbon. So you end up with more diverse ecological productivity and more habitat types for greater numbers of kinds of organisms.

How do you put the Gaia Hypothesis into practice through the Gaia Institute?
Well, really all you need to do to make the world more productive is to add water. If you have lots of water, complex organisms will come in. Therefore, the matrix that causes life on this planet to expand is one that holds water, and that would be soil. So it’s really fairly simple to move the dynamics in a Gaian direction – such that organisms are more productive in regulating planetary conditions – if you cover more of the planet and its cities with soil. Feeding water into rooftops, walls, parking lot edges, the borders of industrial facilities. It’s all the same argument. These systems are biogeochemical. They’re run by the biota.

What is the biota?
Life: bacteria, microbes, plants, animals, like ourselves.

An artificial wetland at the Sims Metal Management recycling facility in the Bronx | Image via The Gaia Institute

For example, I worked on a retrofitting project at the Sims Metal Management recycling facility in the Bronx. When they break down refrigerators and engine blocks to bits, all the iron, copper, and zinc runoff drains downhill. It used to run off into the Bronx River or into some sewer; now it’s all contained on-site in what is essentially a stormwater capturing system. It’s designed to capture five hundred thousand gallons of water, but I know it has captured up to a million. Water flows downhill into a wetland at the edge. It goes into a deep soil column and there are about 240 large plastic domes. They hold about 860 gallons each, so that’s about a quarter million gallon capacity. There are eight solar-powered pumps that move the water out of there and into a green wall and wetland system. It’s making a narrow strip of land the metal recycling company couldn’t use anyway into a water-holding capacity system. All of the metals that run off are captured in that soil column. It’s the only zero discharge industrial facility that I know about.

When did you start working within the design community?
Organisms are like storms. They’re like flames. Essentially they exist to dissipate energy. And it seems depressing, that they basically take energy and make it less useful, but it’s because they’re energy foes that you get certain kinds of functional entities. And so you can either see it as blind evolution or as Robert Rosen did in a book called Optimal Design in the Form of Organisms: optimum design emerging from the play of genetics and the interaction with their environment. So if there are a lot of design structures in organisms, where the hell are they?

I come out of an experimental tradition. I have a degree in Plant Sciences from a joint program of City University and New York Botanical Gardens. I grew plants and bacteria and fungi in test tubes. I looked at which ones interacted favorably and how they did better with one another. It was a kind of experimental design. My mother was a great gardener and I actually designed and built English gardens in high school. I knew how to put plants in the ground and grow them. I grew up with all of this stuff. I used to teach at the New School and I would take my classes to the New Alchemy Institute. They were doing various kinds of design work and they also built things. There the challenge of rooftop agriculture came up. Can we couple plants with buildings? Can you grow plants on rooftops? So I went back to soil structure and the things I knew and started modifying those.

A short video on GaiaSoil by Focus Forward Films on Vimeo.

GaiaSoil is an innovation of yours. What is GaiaSoil and what makes it different from other kinds of soil?
All you need to grow a plant, as people in hydroponics will show you, is nutrients and water. Soil is sand, silt, and clay plus humus. Sand and silt are just silica dioxide, or glass. Clay is an aluminosilicate. Humus is organic matter — basically broken down plants, animals, and bacteria — that stores all of those nutrients, the nitrogen, phosphorus, et cetera. Sand and silt are heavy glassy matrices that don’t do anything except hold water. Standard green roof soils primarily consist of things like expanded shale, expanded ceramics, these chunky things with humus thrown in mixed with compost. In GaiaSoil, I replace those with an ultra-lightweight matrix made of either Styrofoam or eurothane or both. A cubic foot of a glassy matrix will hold 20 pounds of water. A cubic foot of standard green roof material will hold something like ten to twelve pounds. For GaiaSoil, I started from capillarity and basically worked backwards, so I designed it so that a cubic foot holds up to 30 pounds of water.

GaiaMap-danielTell me about the Stratford Avenue Project in the Bronx.
That project originated, in a way, with the New York State Department of Environmental Conservation (DEC), and the Clean Water Act (CWA). New York City regularly exceeds what the CWA’s stormwater and discharge permits allow, and so they have penalties to pay. The State, which is in charge of enforcing the CWA, allowed the City to pay the penalty by building stormwater capture infrastructure. One piece of that infrastructure is being implemented along Stratford Avenue. The DEC took the State’s proposal further, and approached the Forest Service with a plan to create what is essentially an urban forestry project.

Tree pits and infiltration swales along Stratford Avenue | Photos by Paul Mankiewicz and Gabriel Silberblatt

Why on Stratford Avenue specifically?
Because it’s in the Bronx River Watershed, which is an active watershed that is being damaged by a particular combined sewer overflow problem.

Because the avenue runs along a very long hill…
That’s exactly it. I designed two kinds of stormwater capture systems for the city’s program: the enhanced tree pit and the street-side infiltration swale. The infiltration swale is a channel we dug to allow water to flow into the soil. Below the enhanced tree pit is a super large catchment system, originally designed with 8’ x 5’ storm chambers below grade.

At Stratford, we had problems getting these large structures beneath the ground, so essentially we dug holes to whatever depth the excavator could reach — five or six feet. Then we filled that deep hole with recycled glass aggregate. The enlarged tree beds on Stratford are entirely five or six feet of glass. And the neat thing about it is it’s very easy to plant in. Previously, the Parks Department had trouble with trees sinking into sandy loam they’ve put in at other sites. But with this, it’s different. It’s a more robust material because it’s just like gravel. It’s like glassy gravel.

Plans for stormwater swales on Stratford Avenue | Courtesy of The Gaia Institute


Plans for stormwater swales on Stratford Avenue | Courtesy of The Gaia Institute

Why is it you decided to work in New York City?
It’s a, if not the, scientific center of the known universe, because you have institutions like NYU, Columbia, or Rockefeller. Things have been done before here, great things. Great parks were built here. If all you need to do is couple water capture with surfaces, then any city would do. But New York is a juncture, an intersection of northern plants and southern plants. You have greater biodiversity here. When Henry Hudson came up this way, it was probably one of the most biologically diverse places on the planet. And the whole southern Appalachian biogeographic province is the richest temperate flora on Earth.

How can small-scale interventions affect climate and material flows in such a vast ecosystem?
The problem before us is exactly a problem of scale, and if we don’t expand the system we’re building, we’re not going to succeed. What I’m trying to demonstrate now is that expansion of the biota — through green roofs, green walls, street-side planting — does more good than it costs you. The simple proof of that is in air conditioning. If you were to evaporate basically a fifth of an inch of water off a roof, every 250-300 square feet of rooftop would produce one ton of air conditioning. What that means is the same thing that Central Park means for the neighborhoods of the Upper West and the Upper East Side. Basically they are cooler than the rest of the city because the cool from the park just flows downhill and they are better places to live.

Left: Cost of electricity used in air conditioning units in blue, cost of potable water used in vegetation on green roofs to produce a ton of cooling capacity in green. Right: Quantity of water used in electricity production for air conditioning in blue, quantity of potable water used in vegetation on green roofs to produce a ton of cooling capacity in green. | Image via Living Architecture Monitor

Are scalability and replicability key elements to all of your projects?
Yes. For something like $15 a square foot, I could cover almost every one of the 30 square miles of rooftop in New York City. The cost of it would be negative because you could treat all of the greywater, probably even some of the treated wastewater, and the stormwater captured on the site. It would lower the peak electric load requirement of the city, drop the necessity to invest in some energy-producing infrastructure, and drop the heat requirement by about a quarter on buildings between one and three stories. It would make the city more economical.

New York City offers a $4.50-per-square-foot tax abatement for green roof construction, which is a great thing. All you need to do is couple that with some kind of cost sharing between the property owner and the city on the treatment of water. It costs us $2.5 million per day to treat 650 million gallons of water in a wastewater plant. Were you to keep that water on our rooftops it would be worth about $250 million a day in cooling. It’s a very simple step for the Water Board to say “Ok, your property gets $.50/$1 back per hundred cubic feet of greywater that you treat. So you just take your water from your washing machines, your showers, your sinks, separate the risers of your building if you have to, and we will give you that money back. And the coolness, the heating in the building, it’s yours.” That could happen tomorrow, it’s a small step and really the next mayor could do it.

Built systems and cultural and political attention spans exist on a very different time scale than natural systems. How can we reconcile that?
I think the problem is more the silos of thinking. If you think of it like this: “I want to spend as little as possible to treat water, to heat and cool my house, I want the to be able to have the freshest food,” then rooftops should increase the property value of the land. We have absolutely ignored the value of this property — and there are so many square miles of rooftop in this city! We characterize water that comes out of the washing machine as wastewater and throw it away. And we characterize rooftops as being the largest costs of the building, but we never look at their positive side. The economics of walking away from it is senseless.

Green infrastructure strategies for storm surge protection | Image by Rosa Munar Quetglas for Paul Mankiewicz

Tell me about your proposed green infrastructure and storm surge protection strategies to address New York’s infrastructural needs post-Sandy.
There’s nothing to stop the water from coming in. So, you can either build a wall around the whole city. Or you can implement something that will cost us much less than the large-scale “solutions” and will ultimately pay itself back in the framework of 5, 10, maybe 20 years. It could be close enough to the shore that you never get a current over a certain speed going in. Organisms – biota – provide options that could be scaled for our harbor and can be below grade: mussels, seaweed, oyster reefs. If designed for high inputs and anchored well, these types of solutions can slow the water down. But they won’t stop it completely. So you have to work on different levels — seaward, in the bays and along the shorelines, and at the coastal edge. It would be very simple to build these things. They could be aesthetically powerful and be part of the security system.

What do you think our greatest untapped asset is?
Our waste stream. Greywater, treated waste water, even nutrients in the estuary that we dumped in from our wastewater treatment plants. It has tremendous potential.

Also, the 30 square miles of roof space, the 3,000 square miles of wall space, 6,300 miles of roadway edges, and then 500 linear miles of coastline. They were all designed for non-ecological purposes. It could be different. The regulatory structure does not factor in parameters of biology and ecology. How much life is being produced per square meter? It should be at least two kilograms per square meter. It could be five times more.

It’s unusual to hear someone argue that there’s too much unclaimed space in New York City.
But essentially it’s sterile — and is that because we’re stupid? No, it’s because we didn’t take ecological productivity into consideration. But it can be retrofitted. We just have to do it.

Albert Einstein College of Medicine (Left: Existing, Right: Proposed Green Roof) | Images provided by Paul Mankiewicz

Paul Mankiewicz is the Executive Director of the Gaia Institute, exploring through research, development, design and education the interrelationship between human communities and natural systems. Dr. Mankiewicz’s philosophy, which provides the foundation on which the Gaia Institute is based, holds that human communities and natural systems can coexist to mutual benefit. This rests on the hypothesis that where the flow of ‘waste’ materials from human activities can be cleaned and utilized to create habitat, human industry can be coupled with conserving and creating landscapes that provide an abode for life. Such material cycles can enhance environmental quality, where ecological productivity and diversity become goals of human activity.

Click here to watch a video of Paul Mankiewicz presenting a lecture at the Architectural League in 2008 on material flows, ecosystem growth, and urban landscape renewal. 


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