According to the Department of City Planning’s most recent data, 7.1% of New York City’s land is vacant and, for the most part, underutilized. This is a rate much lower than the national average of 15% (in some cities the rate of vacant land is as high as 45%). However, taken together, these properties amount to approximately 11,000 acres of underutilized land — roughly the size of Manhattan (not counting streets). Imagine: across the five boroughs there is enough available land to fill Manhattan, with the potential to grow fresh food, create new parks or build affordable housing. But many of these vacant sites are potentially contaminated by previous industrial uses or leftover building materials, especially lead-based paint. Contamination and the potential health hazards to people who live, work or play on or near such sites become subject to oversight and regulation only in the event of a rezoning permitting residential uses. In those cases, a site receives an e-designation, which identifies it as potentially hazardous due to previous industrial uses. Once designated, site owners are obligated to submit to a process of site investigation and clean up.

50% of all vacant lots in New York City are smaller than 2,500sf and are owned by individuals. Click to enlarge.

In May of 2009, Mayor Bloomberg signed the New York City Brownfield and Community Revitalization Act, a milestone in the City’s commitment to cleaning up brownfields for productive reuse in accordance with PlaNYC. Citing the scarcity of land in New York City and the anticipated influx of one million new residents by 2030, PlaNYC identified the importance of cleanup and redevelopment of properties that are abandoned and underutilized due to the presence or perceived presence of contamination. As part of this effort, the City has created the Office of Environmental Remediation, which oversees the environmental review of brownfield sites and offers assistance to property owners on the path to a Green Property Certification and potential redevelopment.

50% of all vacant properties in the city are smaller than 2,500sf and individually owned. 80% are smaller than 5,000sf. Remediation, typically in the form of excavation of the contaminated soil, is costly, despite programs, assistance and grants now available. As a result, these small properties lie vacant for years, underutilized and toxic, their value further diminished by the appearance of abandonment and potential contamination.

We created a Field Guide to Phytoremediation to illustrate how property owners can use these years to their advantage and initiate a slow but cost-effective clean-up process using nature as their ally to add 11,000 acres of productive, usable land to the City‘s healthy environment.

Phytoremediation is the use of plants to remove contaminants from the environment. By harnessing the natural capabilities of plants we can remediate toxic soils, groundwater, surface water, and sediments. Phytoremediation is a low-cost alternative to traditional brownfield clean-up. Instead of removing tons of toxic soil and filling the site with new clean soil, plants remove contaminants from the soil and store it within their plant tissue. In some cases, the plants themselves then have to be removed as hazardous waste, other plants break down the toxins and eliminate them altogether.

Click to enlarge.

Contaminants successfully removed in field studies have included heavy metals, radionuclides, chlorinated solvents, petroleum hydrocarbons, polychlorinated biphenyls (PCBs), pesticides and explosives. In order to successfully remediate toxins in soil or water, the appropriate plant groups have to be planted and monitored. Different plants have different remediative qualities. Plants offer an aesthetic as well as an environmental value to the city beyond the phytoremediation process. Improved air quality and reduction of storm water run-off are among the additional benefits of planting on sites that would otherwise be underutilized until funding for soil removal becomes available.

The costs associated with remediating lead contamination on a 2,500sf lot through phytoextraction using Indian Mustard can be reduced to 10% of those using common methods of excavation and fill.

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The steps below describe a one-year process of testing, planting, monitoring and harvesting. Depending on the level of contamination, this cycle can be repeated for several years until levels of metal or PCBs in the soil reach the minimum recommended by the NYS Department of Environmental Conservation.

	1. COLLECT A SOIL SAMPLE Gather soil samples by taking them from at least 4 different areas per every 400sf of space. Samples should come from approximately 6 inches below the surface and should not contain any gravel, grass, trash, etc. You can mix the samples to form a composite sample of your entire lot.
	2. SEND IT TO A LAB Brooklyn College and Cornell University provide inexpensive soil testing services (approximately $30 for heavy metal tests). The NY State Department of Health also offers a list of certified professional labs on its Wadsworth Center website. Fill a zip-lock bag with your soil and send it to the lab together with information about your site. You will get a report in about 2 weeks.
	3. CREATE A REMEDIATION STRATEGY From the test results, determine if and how you should remediate contaminants. See the chart at the end of this post to determine which plants would best help you clean up your lot and how many you will need.
	4. START PLANTING Most of the seeds you will need are sold online. Sow and germinate them in a small container and water them regularly. Transplant them to your site when they are about 3“ high and after the last spring frost. Manage them as garden plants and watch them grow.
	5. HARVEST AND RE-PLANT After about fourteen weeks, your plants will be saturated with heavy metals, PCBs or other toxins. Harvest the entire plant, including the roots, stems and leaves, and repeat this growing cycle as often as climate permits.
	6. DISPOSE AS HAZARDOUS WASTE Some plants are hyperaccumulators. They store the toxins within their plant tissue and, after this process, will themselves be toxic. Check for the location of the Special Waste Drop-Off site in your borough and dispose of them as hazardous waste. Keep them away from children and animals.
	7. RE-TEST YOUR SOIL At the end of the growing season, re-test the soil to track the improvements. You can also test the plant material if you are curious about the change. Depending on the level of contamination at the site, this planting process may have to be repeated over 2-3 years.

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The table below gives examples of levels of acceptable soil contamination for certain recreational, residential or food production uses (as recommended by the NY State Department of Environmental Conservation) and suggests plant material most effective in remediating each contaminant.

Click to enlarge.

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We would love to help and put this research into action. So, whether you are an individual property owner or community group with little budget but plenty of energy and a vacant lot that might be contaminated, get in touch!

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Update, July 2011: “Step #8: Get a Green Property Certificate,” which appeared in an earlier version of this article, has been removed to avoid misunderstandings about the certification process.

This project was originally submitted to the One Prize: From Mowing to Growing competition in May 2010. Lisa Brunie, Erik Facteau and Jay Tsai assisted in research for the field guide.

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SOURCES:
1. US Environmental Protection Agency. “Re: Contaminant Focus.” Contaminated Site: Clean-Up Information. US EPA Office of Superfund Remediation and Technology Innovation, Washington, DC, 7 Jan. 2010. Web. 22 Apr. 2010.
2. New York State Department of Environmental Conservation. “Re: 375-6-8 Soil Cleanup Objective Tables.” Subpart 375-6: Remedial Program Soil Cleanup Objectives. NYS DEC, Albany, NY, 14 Dec. 2006. Web. 22 Apr. 2010.
3. Wikipedia, The Free Encyclopedia. “Re: Hyperaccumulators Table – 1 and 3.” Redirected from, Phytoremediation, Hyperaccumulators. Wikimedia Foundation, Inc. San Francisco, CA, 14 Apr. 2010. Web 22 Apr. 2010.
4. U.S. EPA. 1996. Soil Screening Guidance: User‘s Guide. Office of Emergency and Remedial Response, Washington, DC. EPA/540/R95/128.
5. Schippers, R.R. & Mnzava, N.A. Brassica juncea (L.) Czern. [Internet] Record from Protabase. van der Vossen, H.A.M. & Mkamilo, G.S. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. 2007. Web. 22 Apr. 2010.
6. Duke, James A. Brassica juncea (L.) Czern. Handbook of Energy Crops. unpublished. Center for New Crops & Plant Products, Purdue University, 1983. Web. 22 Apr. 2010.
7. Shayler, Hannah, Murray McBride and Ellen Harrison. “Re: Guide to Soil Testing and Interpreting Results.” Cornell Waste Management Institute. Department of Crop & Soil Sciences, Ithaca, NY, 15 Apr. 2009. Web. 22 Apr. 2010.
8. Environmental Science Analytical Center. Soil Testing Brochure. Department of Geology, Brooklyn College, Web. 22 Apr. 2010.
9. Washington State Department of Ecology.  Dirt Alert – Soil Sampling Guidance for Owners, Operators and Employees of Small Properties Where Children Play. Publication #06-09-099. Olympia, WA, Sep. 1999. Web. 22 Apr. 2010.
10. New York City Department of City Planning (Land use summary, 2007)
11. Michael A. Pagano and Ann O’M. Bowman: Vacant Land in Cities, Brookings Institution Report, 2001

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Kaja Kühl is an urban designer and principal of youarethecity, a research, design and planning practice interested in creating dialogue about the urban environment. She is an Adjunct Associate Professor at Columbia University.

The views expressed here are those of the author only and do not reflect the position of Urban Omnibus editorial staff or the Architectural League of New York.

Culver Viaduct | Photo by John McGill

Infrastructure as Urban Opportunity
As infrastructure in our cities reaches and exceeds the end of designed life spans, the necessary upgrades, repair, and replacements to these aging systems require significant public investment. According to the American Society of Civil Engineers, some $2.2 trillion of investment will be needed to address US infrastructure needs in the next five years alone. At the same time, urban park development increasingly involves cooperation with, and concessions to, the private sector to offset the need for public investment. Vacant land suitable and available for new public space and other essential local amenities is, for obvious reasons, hard to come by. It is therefore no surprise that last summer’s opening of the High Line’s first segment was so highly anticipated and widely discussed: infrastructure is increasingly seen as a locus of opportunity.

The seemingly inaccessible and useless spaces of urban infrastructure have a value beyond their (often awkward) adjacency to newly viable real estate: they are already inscribed with highly specific relationships to surrounding urban fabric, and as intervention sites can therefore mediate between radically different scales, speeds, and programs.

Underneath the Culver Viaduct | Photo by John McGill

Activating Urban Void Spaces
Large pieces of transportation infrastructure have traditionally been built to address a singular, performance-driven use, and those conceived and built at a particular moment in history were often over-engineered to accommodate (or privilege) other layers above, below and adjacent. Precisely because of these attributes, they serve as translators between adjacent systems, producing as byproduct large volumes of space with odd relationships to surrounding buildings, streets, and their respective orientations. These transportation systems offer a scaffold that is scaled to the city, relevant to its history, and generally oversized but underused – structures that have the latent potential to organize public space more actively and to support a vibrant mixture of urban programs based on immediate local needs and conditions.

As these systems age and must be upgraded or replaced they provide a unique opportunity for us to expand the meaning and scope of “adaptive reuse” in the urban context. The ubiquity of such decaying structures in our cities, and their resulting firm – but conceptually uncertain – presence in the public conscience, suggests an inherent economy by which space can be found for activities that are unlikely to be adequately addressed by conventional development scenarios.

Layers of space formerly ignored or associated with the banality of a particular engineering problem must now be reconsidered and addressed in this moment of heightened interest and investment in infrastructural upgrades and repair. By actively engaging them, such spaces can be folded into the public realm, making them at once more legible and less obtrusive to contemporary patterns of land use, transportation and culture. This strategy instrumentalizes infrastructure for public use and local benefit, not as an afterthought to private development but as an existing and potent prefigurative device for urban change.

The Culver Viaduct
In the Gowanus, what appears to many an abandoned and contaminated area standing as an impediment to economic development is in fact already teeming with activity, albeit behind closed doors and at a relatively small scale compared to the area’s more intensive industrial past. What is lacking is a coherent and legible public arena in which interaction among the diverse group of current users can occur. Indeed, while public access to the canal is no longer blocked by active industry, it will remain mostly sealed off as the estimated 12-year Superfund cleanup process begins.

The Culver Viaduct, which carries Brooklyn’s F and G subway lines over the Gowanus Canal, offers a prime opportunity to implement precisely this strategy. Given its legitimate place in local history and the public imagination, the viaduct offers an ideal armature within which to stage a new set of conditions for the broader Gowanus site, without touching the most ecologically damaged areas at all. And it happens to be currently undergoing a $300 million replacement of its concrete structural deck. What follows is Underline, my design proposal for the Culver Viaduct — an opportunistic repurposing of existing, functioning infrastructure to address the need for a vibrant and coherent public realm. Unlike the High Line and many other recent adaptive reuse projects that employ linear infrastructure as an armature, this strategy is not dependent upon the termination of active rail (or other) service in order to produce viable sites for intervention.

Site History
When completed in 1938, the Culver Viaduct was the only elevated portion of the original Independent Subway system, and reached a height of 90 feet above grade in order to accommodate tall ships on the Gowanus Canal while also supporting two above ground stations. With the canal and its banks recently designated a Federal Superfund site (in March, 2010) and now mostly unused for shipping of any kind, the extreme vertical separation of these layers can be reconsidered: the concrete structure both offers large volumes of valuable “free” space and is the threshold to contaminated ground.

Because the curving train line is not constrained to the urban grid, the structural piers transpose the geometry of the rail bed to the streets below, with columns landing on sidewalks but not the streets themselves. The result is an array of unique spatial conditions, each with a slightly different disposition relative to surrounding streets and buildings.

The structure’s dimensions, despite being highly irregular and specific to local structural demands and adjacent site constraints, are ideal for inhabitation – increments are generally between 15 and 20 feet in each axis, providing spaces of a useful scale.

Underline Section | Rendering by John McGill

The Scheme
Four types of “preservation” emerged as essential to the architectural strategy: preservation of sunlight, of structural stability, of limited footprint at ground level, and of existing (historic) character. Informed by these criteria, Underline offers four potential modes of intervention: the creation of flexible space for public assembly; precast concrete decking hung from above on steel rods as a public landscape “ribbon;” pure infill at ground level; and adaptive reuse of, or interface with, existing adjacent structures.

Sunlight animates the existing structure and is essential to the unique experience found on the sidewalks around Smith and 9th Streets. Aggressive infill of the viaduct’s undercarriage – a strategy often employed in Europe – would compromise this special quality and risk casting a shadow over any future street life. A 3D analysis of solar exposure within the space of the viaduct throughout the year revealed that despite its inherent drama at sunset, it remains dark throughout most of the day, year round.

Underline Solar Exposure Analysis | John McGill

The solar analysis led to a strategy of puncturing the deck of the viaduct strategically, cutting openings within the supporting piers and inserting steel lattice “skylights” to carry the rails overhead. Enclosed volumes of multipurpose classroom space could then be clustered below the openings, within the existing structural frames. Each volume is shaped by the angles at which the sun tends to reach the street below, so that the persistence of large areas of shadow is minimized. By night the relationship reverses: prismatic volumes glow with artificial light, projecting it into the darkness of the canal.

In order to preserve the integrity of the existing structure, asymmetrical loads would have to be avoided. We can’t assume that the existing reinforced concrete truss members are capable of carrying additional load. This means that the route of the pedestrian ribbon is largely dictated by the clearances found within and between the trusses at various heights above the street, and the places where it can be fastened to the re-engineered deck above for support. In areas where existing (but unused) playgrounds and vacant land exist beneath or adjacent to the viaduct, the landscape ribbon is free to move outboard to form the roof for new enclosed spaces below, and offers views and pedestrian access into each space. The ribbon tapers and swells as it moves through the structure, seeking light and connecting opportunistically between discreet elements of the program.

Underline Pedestrian Walkway | Rendering by John McGill

The fourth mode of intervention, adaptive reuse, occurs primarily at the concrete plant at Smith and 9th Streets, which is the only active business immediately adjacent to both the viaduct and the canal itself. Once decommissioned, the structure could be reinvented as a climbing wall – an injection of new activity to animate and preserve an evocative and representative historic structure.

Preserving this set of desirable existing conditions results in a series of distributed spaces connected by a linear public park. This establishes a sequence of unique visual experiences as one moves along, offering glimpses of unexpected adjacent activities, the regular appearance of moving trains overhead, and the rhythmic discharge and departure of passengers to and from the stations at either end of the project site — not to mention views of the city currently reserved for F and G subway riders.

Despite being distributed, however, the program is arranged in discernible clusters so that points of access to each component of the project are clearly legible from the street. Starting from the south, the first of these might contain an EPA monitoring station and public exhibition space, a café, public outdoor amphitheater, rock-climbing wall, and classrooms. The next section consists of covered outdoor basketball courts and a small public fitness center and lap pool, and in the final group retail and production spaces. Because each element is knit into the whole by the landscape ribbon, a loose affiliation emerges between both related and unrelated events in time and space.

Underline Public Amphitheater | Rendering by John McGill

The project also includes a provision for storm water collection on the surface of the rail deck, with drains feeding hanging gardens of deciduous vines suspended on wire mesh from the rods supporting the landscape ribbon, as well as the plantings along the ribbon itself. Such plants would perform in two ways – filtering and retaining storm water before it reaches the street or the canal as runoff, and filtering light during the summer to shield passersby. As a repetitive element related to the structural cadence of the existing viaduct, the hanging vines would further reinforce existing tensions between the geometry of the viaduct and the city around it.

Initially an elevated platform for public observation of a compromised landscape, this thin viaduct could eventually shed its image of forbidding overpass, under which people move by default, confined by fences and traffic, and emerge as a vital, engaging public passageway and gateway – a shift from mere edge to public threshold.

Underneath the Culver Viaduct | Photo by John McGill

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John McGill is a designer at WRNS Studio in San Francisco and a recent graduate of the masters program in Architecture at UC Berkeley, where he occasionally teaches as a lecturer in architecture. He grew up in Carroll Gardens riding the F train and now lives in Berkeley.

The views expressed here are those of the author only and do not reflect the position of Urban Omnibus editorial staff or the Architectural League of New York.

A “skyscraper showdown” is in headlines this week, making contentious building projects a recurring theme for the summer. This time we have 15 Penn Plaza vs. the Empire State Building. The City Council has approved plans for a 67-story tower to be built two blocks away from, and just 34 feet shorter than, the iconic Empire State Building. Detractors claim New York’s skyline will be ruined and views of the city’s most recognizable structure will be obstructed, and the sole councilperson to vote against the project, Charles Barron, dissented due to what he saw as an insufficient number of contracts set aside for minority and women-owned businesses; supporters point to job creation, economic development, and the constant growth and change intrinsic to our fair city. Meanwhile, Brian Lehrer asks how this hasn’t come up before and over on Co.Design, Ken Carbone offers up a few alternative ways for the structure to stake its claim on the skyline.

It’s no surprise, thanks to the dysfunctions of Albany and the (many) gubernatorial scandals of recent years, that this year’s candidates for Governor of New York are promising reform and change. But on one topic of great concern to the NYC metropolitan area in particular, public transit and the extraordinary debt faced by the MTA, the candidates’ platforms are unclear. In an op-ed in the Albany Times Union, John Petro and Dan Morris of the Drum Major Institute point to Albany and the state government’s inadequate investment in public transit as a primary cause of the MTA’s now-spiraling deficits and they call on the candidates to clarify their platforms and voice their ideas. In the words of Petro and Morris, “Our public transit system is an irreplaceable asset and an invaluable part of the nation’s infrastructure that should be protected. Leaders in state government better start treating it that way.”

Early last year we talked to Colleen Werthmann and Michael Premo, two of the minds behind Brooklyn at Eye Level, a theater performance with a journalistic approach that explored all aspects of and viewpoints on Atlantic Yards. This fall, the investigative theater company The Civilians is updating the material gathered for that production to present In the Footprint. Again bringing interviews and documentation about the development to the stage through dance, music and spoken word, The Civilians offer a multifaceted portrait of a complex project. In the Footprint will run from November 12 through December 11, 2010 at the Irondale Center in Fort Greene, Brooklyn.

The Center for Urban Pedagogy has released its latest video, produced by a group of students from Brooklyn’s Walt Whitman Middle School who ask: Why are there so many empty lots in our neighborhood? The Good, the Bad, and the Empty, which premiered on Places this week, takes us on a vacant lot tour of Flatbush and follows the students as they question local residents, landowners, community activists, and city officials about the existing conditions of the unused lots and why they were left dormant in the first place. The students find everything from trash-strewn, abandoned “construction sites” to well-tended community gardens, and share their ideas to activate these vacant, underutilized spaces.

The Roundup keeps you up to date with topics we’ve featured and other things we think are worth knowing about.

Speaking of what you can do with the city, The Putting Lot is a collective of professionals from different backgrounds that will bring miniature golf to a vacant lot in Bushwick for the summer. Designs for the course’s nine holes are currently being solicited through an open design/build competition. As a proposition for urban design, the competition’s submissions are meant to engage with themes of urban sustainability, and a stipend of $500 will be provided for the construction of winning entries. See the competition brief for more details.

The Architectural League was an early promoter of the ability of design expertise to add value to urban space. Back in 1992, the League curated The Productive Park: New Waterworks as Neighborhood Resources, which examined the potential use of city-owned property atop aquifers in Brooklyn and Queens to simultaneously expand the city’s supply of water and public space for recreation.

In the years since, empty space in the city has gone from being seen as a liability, prone to crime and symbolic of urban decay to being considered an asset to be used for public benefit.  The urban agriculture movement flourished as part of this transformation, as community gardeners and urban farmers gained legal status for their productive use of neglected property.

The Putting Lot has secured a spot for a recreational amenity in Bushwick, offering an interesting new program for an underutilized vacant area. There’s still time to submit your designs, so get out your pencils: the competition deadline is 6pm next Monday, April 27.

The views expressed here are those of the author only and do not reflect the position of Urban Omnibus editorial staff or the Architectural League of New York.

In this piece, Deborah Greig, Urban Agriculture Coordinator for East New York Farms!, explains the history of the organization in the context of the neighborhood.

For more on East New York’s history since the early 1960s, a good first place to look is Walter Thabit’s 2003 book How East New York Became a Ghetto.

In this piece, Holly Leicht, Deputy Commissioner of Development at HPD, explains the recent history of the city’s involvement in East New York and how strategic site disposition enabled the homegrown urban agriculture movement to flourish.

In this piece, we meet Johanna Willens, the first farmer to sell her produce at the East New York Farmers’ Market in 1998.

For all you budding urban farmers out there, here are some
DIY tips to get you started on your own community garden:
First, the materials:
The New York City Compost Project
Gardens Alive

Then, some community workshops:
Brooklyn Botanic Garden: Gardening Page
Green Thumb NYC

And finally, some tip sheets and online resources:
The City Farms Tipsheet
OrganicGardening.com