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MALDEN RIVER MAKEOVER

A brownfield redevelopment project shows how landscape architects can collaborate on damaged sites. By Daniel Jost, Associate ASLA

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A brownfield redevelopment project shows how landscape architects can collaborate on damaged sites. By Daniel Jost, Associate ASLA

ike many landscape architecture firms, Shadley Associates is a firm of generalists. They do not specialize in restoring wetlands or remediating brownfields. "The client and the public rely on us to provide the vision, to make a place people really want to be in," says J. p. Shadley, ASlA, founder of the lexington, Massachusetts-based firm. At River's Edge, a mixed-use development being constructed on a former industrial site, Shadley has been involved in creating such a "vision"

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Derelict industrial buildings, top, have been removed. Rather than preserving a highly degraded, low-quality wetland in the middle of the site, left, new and restored wetland areas were created along the river's edge. The darker areas of the conceptual plan, below, have been completed. The faded areas were not yet complete this summer. If the project is successful, the developer hopes to break up the parking lot with additional buildings.

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| Landscape Architecture

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GR EIG CRANNA, LEFT; LES VANTS AERIAL PHOTO, CENTER; COURTESY SHADLEY ASSOCIATES, BOTTOM

MALDEN RIVER MAKEOVER

In Medford, Massachusetts, an industrial site used for dumping tires, above, is being transformed into a mixed-use development called River's Edge. To help sell the project, a park along the river, left, has been completed before any buildings are built.

since the 1990s, when he helped develop a master have led public meetings, and they've worked on the phragmites, it provided little value for wildlife. plan for the site while working for CRJA in Boston. conceptual design, grading, plant selection, and de- "The scientists from Tetra Tech Rizzo rated biodiTheir master plan's emphasis on open space helped tailing. However, they've never worked in a vacuum. versity really, really low," says Shadley. Meanwhile, Shadley was grappling with anothpreotle, lane, and Associates win a national com- Two of the most important design moves at River's petition to become the master developer for the Edge, the location of the wetlands and the use of a er problem: The central location of the wetland site, which was assembled by a public development living fence, were the result of collaboration between would make it difficult to integrate into their development plans. While new wetlands created to recommission. And Shadley's firm has been involved landscape architects and other professionals. place native wetlands are often less effective, scienwith fleshing out these plans since he founded it tists pointed out that relocating this one could five years ago, designing a new park along the Placing the Wetlands Malden River in Medford, Massachusetts. The landscape architects consulted with wetland actually make it more functional. "The wetland sciThe site has undergone a major transformation. scientists from Tetra Tech Rizzo throughout the entists all said that the best way to do this was to For many years, the riverbank was used as a dump- planning and design stages. When the scientists put [the wetland] next to the river," says Shadley. ing ground for old tires. It was strewn with trash were first brought in to delineate existing wetlands, And Shadley followed their advice. However, not all "wetlands next to a river" are and overgrown with invasive species such as phrag- they discovered a highly degraded wetland in the created equal. The banks of the river at River's mites and ailanthus. "This area was so bad in some middle of the site. places, you couldn't even see the river," says developWhile this area had saturated soil, it was provid- Edge drop off 15 feet at a fairly steep grade. An er John J. preotle Jr. In addition to the tires, there ing few of the benefits that make wetlands worth early plan would have placed the wetlands high above the water level. This solution would have was a steel barge full of trash that had been stuck in protecting. The soils were heavily allowed the wetlands to intercept surthe river since the 1960s. face flow before it reached A barge full of trash is not the sort of waterthe front view that sells office space or condos. So, to increase interest in the property, which is planned to have both office and residential components, preotle has taken a big risk. He has not only cleaned up the site but developed five acres of parkland before any building is completed. preotle has spent more than $17 million up front with no guarantee of returns, but "our sense was that if we didn't [develop the park first], no one would ever believe Shadley Associates that it would be done," preotle says. created undulating landforms, above, where visitors Shadley Associates' design for the can sit and watch paddlers from Tufts University and local high schools. park at River's Edge combines natu- The naturalistic areas along the river are divided from the campuslike inland areas by a sweep of roses, below. ralized wetland areas at the water's edge with campuslike lawn areas farther inland. At compacted and the the center of the site sits a boathouse and docks built wetland had no hyfor the Tufts University crew team. A multipurpose dric connection to asphalt path runs along the entire site--eventually it the river, meaning will connect pedestrians to a nearby transit station-- that it was not while a narrow, stone dust path provides opportuni- recharging groundties to get closer to the water. water. The wetland's But never too close. A long sweep of roses mixed location meant that with other thorny vegetation restricts access to the it was doing little to shoreline. Views of the river have been opened up intercept and cleanse by replacing invasives such as phragmites with low- surface flow on its growing native plantings. Serpentine granite walls way to the river eiand benches throughout the site provide places to ther, and since it was sit and look out over the river and the wetlands. primarily a monolandscape architects with Shadley Associates culture of invasive

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G REI G CR ANNA, TO P AND BO TT O M; CO URTE SY S HADLE Y AS SO CIAT ES , CENT ER

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river; however, due to their height, unless they were lined in some way these areas would have drained fairly quickly. They would have been wetlands in name only. preotle initially preferred this solution because he was concerned about what sorts of contamination crews might find digging around the riverbank. However, after the Tufts Boathouse and docks were constructed in 2005, the aesthetic benefits of providing open views to the river became clearer. preotle agreed to remove large volumes of landfill soils to create a new wetland that ties into the river directly. At the wetland's widest point, the bank was moved back 56 feet and lowered 15 feet, creating what looks like a natural floodplain. New wetland soils were spread over the area, and it was hydroseeded with 14 herbaceous wetland plants including Canada rush ( Juncus canadensis) and soft rush ( Juncus effuses). A nurse crop of annual ryegrass was used in the hydroseeded areas to keep the soil in place during the initial growing season. In other areas, the existing riverine wetland was restored, though not in the purest sense of the word. These areas were tidal and brackish until the construction of a dam downstream. Now they are freshwater wetlands, and there is less variation in the height of the water. Here, most of the invasive species were removed, and nine species of native shrubs were planted--shrubs such as summersweet (Clethra alnifolia) and buttonbush (Cephalanthus occidentalis). Shadley

A sunken barge and landfill soils, above, were removed to create a new wetland that is hydrologically connected to the river, below. New soil was brought in, and the area was hydroseeded with a mix of native species and annual ryegrass. Since the wetland's first year, bottom, keeping out invasives has been a challenge. A "living fence" was planted with roses and other thorny species, see page 5, to keep people from entering the river, which is not safe for fishing or swimming.

says the state requested that they retain an invasive Norway maple tree, at least temporarily, due to the habitat it provides.

Today the wetland is much more biologically diverse than in years past, and it is attracting a large number of bird species. However, there have been

GREIG CRANNA

GREIG CRANNA

issues with invasive species returning to the site and new invasives taking hold. While little of the wetland has been recolonized by phragmites in the year since it was constructed, other invasive species including Chinese hops and lady's thumb have a significant presence on the site. "You have to say to yourself, is this sustainable ultimately with phragmites [on another site] across the river? The answer is no," says Shadley. To keep the wetland free of invasives, it will need to be weeded like a garden. During the first five years, at least, that is what they plan to do. "We're only a year or so into a five-year program to establish habitat," says Shadley. The state monitors all new wetlands for five years after they are constructed to make sure they retain 85 percent cover with native wetland species. Shadley hopes that by this point, the shrubs and perennials he specified will be high enough to compete effectively with the invasives. Collaborating with the Licensed Site Professional In 1993, the Commonwealth of Massachusetts was the first state to create a licensure program for private sector engineers and scientists involved in assessing and cleaning up contaminated sites. Massachusetts refers to these scientists and engineers as licensed site professionals (lSps). Because it's a

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young profession, there is not yet uniformity across state lines. Connecticut instituted a similar program, but participants are called licensed environmental professionals. Other states may have no specific licensure program or they may require that remediation plans be led by state agencies rather than private consultants. At River's Edge, the lSp and landscape architects worked together throughout the project. "We like to view it as an interdisciplinary effort," says Jeff Nangle, the lSp and principal of Nangle Consulting Associates. "Everyone comes together in the selection of the site remedy." Where small localized areas of contamination posed a threat to groundwater resources, the soil was removed and the threat eliminated. However, most of the site remained contaminated with heavy metals that pose no threat to the groundwater. Therefore, the entire site was covered with a cap, which is a minimum of three feet in public spaces and most other parts of the property. The cap is composed primarily of gravel, though the topsoil layer is also considered to be part of the cap. There is a warning fabric two feet deep meant to keep people from digging into the contaminated areas. Unlike the clay caps that more landscape architects may be familiar with, this cap is not meant to prevent leaching; it is merely meant to prevent direct contact with the soil.

But how would the landscape architect and

lSp keep people away from the shoreline? While

the project has cleaned up that area of the shoreline and the wetlands pose no significant risk to the public, the riverbed itself is believed to pose a health risk. Only controlled uses such as boating are allowed in the river; people cannot swim or fish. At first, the team considered solving this by putting a fence along the edge. But Shadley says this would have blocked views of the water for people sitting on the benches. It also would have made the view less natural. So they looked to an alternate method, a "living fence." A row of prickly and thorny plants was planted to keep people from entering the river. This barrier will be kept two to three feet tall and is at least six feet wide in most areas. It consists primarily of low-growing roses, but there are also some junipers. Shadley originally planned to use a more diverse selection of plants, but the roses were chosen for their floral quality and the ease with which they could be obtained. How effective this particular living fence will be at keeping out the public cannot currently be assessed, as the park was not yet open to the public when I visited in August. living fences have been used with success on many other sites. But as landscape architect Thomas Russ, who wrote Redeveloping Brownfields, points out, "people routinely

| Landscape Architecture

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Serpentine granite walls, here and on the cover, referencing the seawalls along many local rivers, provide a place to sit and look out over the water. A smooth finish was used on the top of the walls to tie them into the sleek new offices planned adjacent to the site. At one location, stainless steel and wood seats, top left, are used to provide more comfortable seating.

move through fences and hedgerows unless the effort is greater than the perceived reward. A river could be a significant inducement." While I am usually fairly adventurous, I was not drawn to pass over the roses. The junipers, which were allowed because of their skin-irritating properties, seem to present less of an obstacle at their current size (and one has to wonder how much of a deterrent those skin-irritating properties would be to an adult wearing jeans even after they've grown). However, the steep slope would seem to deter most people who would be deterred by a fence. Nangle says a living fence is not a good choice for every property due to its maintenance requirements. "At a public park without a management entity, it wouldn't work," says Nangle. "There is an entity here to keep this wall in place. That's probably the most important part of the maintenance going forward." Another area where the lSp worked closely with the landscape architect was the grading of the cap. The cap is deeper in areas where the landscape architects designed berms. "We did a lot of work with the undulating landforms so that it feels a little bit more private but still safe," says Shadley. You can just see the top of the bench over a mound. "The mounds will be great sitting spots," he says. "When you have a boating competition, this is like an amphitheater. You get to watch them race the last stretch." While landscape architects working on brownfields with a clay cap meant to prevent leaching need to select shallow-rooted trees to make sure they won't penetrate the cap, that was not a concern on this site, according to Nangle. Instead of worrying about their root systems, Shadley was able to concentrate on another issue--choreographing their fall color. He says the first to turn are the golden leaves of the river birch, followed by the deeper orange red of the sugar maples, and finally, the strong burgundy of the red oaks. Russ says that landscape architects working on brownfield redevelopment often find themselves in familiar roles. "Since most landscape architects will be working in a team with other professionals, they are primarily responsible for bringing their traditional knowledge to the project," he says. "Conditions and concerns on brownfield redevelopments vary significantly from project to project so a detailed knowledge of the physical and legal aspects of the contamination or health concerns is not expected." That said, Russ says that the more knowledge you do have about strategies for addressing brownfields, the more effective a collaborator you can be. "The good news," he says, "is that knowledge is readily available and fairly easy to acquire." L AM

PROJECT CREDITS: Owner/client: preotle, lane & Associates ltd., New York ( John J. preotle Jr., principal; Harry G. Bovee III, project manager; Brendan M. Sullivan, construction manager). Landscape architects/site planners: Shadley Associates, lexington, Massachusetts ( J. p. Shadley, ASlA, principal in charge; Kathleen Ogden, ASlA; Jason Bobowski; Uma Sankar). Development oversight: Mystic Valley Development Commission, Malden, Massachusetts. Office building architects and site planners: Gensler, Boston. Civil engineer and general contractor: Tetra Tech Rizzo, Framingham, Massachusetts. Licensed site professionals: Nangle Consulting Associates Inc., Canton, Massachusetts ( Jeffrey A. Nangle). Boathouse architect: peterson Architects, Cambridge, Massachusetts.

Reprinted with permission from landscape Architecture, November,©2008 American Society of landscape Architects. By The Reprint Dept. 800-259-0470 (11333-1108). For web posting only. Bulk printing prohibited.

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