The 9/11 National Memorial and Museum at the World Trade Center site in New York City took over seven years to complete, and cost well over the original estimated $500 million budget. (Unofficial figures put the final price tag at over $700 million). The challenges of working on these highly-anticipated projects were numerous, but not all of them were obvious to the general public. James Stawniczy, VP of Sustainability for Lend Lease, painted a vivid picture of the experience at our recent Technical Roundtable.
As general contractor for the 110,000-square-foot Memorial and Museum, Lend Lease was tasked with meeting a range of mandates including tax credits, LEED Gold Certification and other sustainable design requirements.
In total, the WTC site had six billion dollars’ worth of work going on during this period – including construction of One World Trade just north of the Memorial, the transportation hub to the east, and a new tunnel to connect the PATH train with the Fulton Street subway. Stawniczy explained that because the site was below grade, it functioned as “a big drain. Any fumes, exhaust, water, or construction dust coming from operating equipment around our site went into ‘the hole’,” said Stawniczy. As a result, managing site air quality was an ongoing issue.
In addition, Lend Lease contractors and sub-contractors had only one access road to transport all materials in and out. In order to coordinate everyone's efforts, one employee was one dedicated to creating phasing drawings on site. The drawings outlined where various subcontractors should be working each day, how other work on the site might impact them, and other relevant information.
Stawniczy was also responsible for 9/11 artifact preservation. He described it as similar to “working in Pompeii. We are building a new building around it, but we can’t touch the original stuff.” It involved “constant protection, constant checking” of artifacts such as the footings of the original World Trade Center, the last standing column, and the slurry wall (the original wall that holds back the Hudson). These surviving structural elements would be part of the final museum, so it was important that they not only be physically protected but also treated with respect. Workers were asked not to dispose of garbage on these cement artifacts, although they looked like part of a regular construction site, and asked in general to treat them with care. In one case, however, “somebody ran a lift down the ramp and punctured a little piece of the footing off,” Stawniczy recounted. The historic architect labeled the piece “and we put it in a storage room. And one of the last things that was done, upon delivery of the Museum, was that it was glued and epoxied into place. Which just goes to show you the sensitivities of what we were doing.”
The full collection of Ground Zero artifacts were lowered into the museum site shortly before completion of the Memorial Plaza in 2011. The Memorial opened on the 10th anniversary of the attack, but the Museum was still under construction. Unfortunately, 13 months later (three months before Lend Lease was going to hand over the Museum to the curatorial staff) Superstorm Sandy flooded the building with 16 feet of water. All the plywood, sheetrock, and insulation had to be removed. Stawniczy remembers it as a very sad day. “We basically had the biggest waste project in the world.” The material had to be transported to special waste sites because it was contaminated with fuel oil from flooded equipment tanks and other toxins, and could not be recycled. “It was a big setback.” The Museum was finally opened on Sept 11, 2013.
The project awaits LEED Gold certification. Stawniczy estimates that his team was able to divert 78% of construction and demolition waste from landfill (not including Sandy related waste), and used 50% FSC certified wood in the project overall. The team also reclaimed water from “the hole” and used it to suppress construction dust in other parts of the site (reducing use of potable water) and they retrofitted all of their diesel equipment to make them exhaust efficient.
The site requires careful maintenance as a somber site for reflection. The black granite edges of the pools, inscribed with almost 3,000 names, are actively cooled by chilled water pipes so that they don’t overheat and burn visitors’ forearms on sunny days. It takes a battalion of pumps to keep the waterfalls circulating, and on hot days, thousands of gallons of potable water to replace losses from evaporation. To address these issues, the Memorial Plaza will rely primarily on rainwater collected in tanks below the Plaza for daily irrigation use, and the grove of locally harvested swamp white oak and sweetgum trees (eventually totaling 400) are expected to provide full shade within five years – and serve as a green roof for the Museum, the train station and other facilities below.