Hvac Cleanup Work At Ground Zero Continues
David Shagott, president of Abatement Technologies, Inc., Duluth, GA, recently spoke about his company’s role in the cleanup. Although Shagott himself has not been to the Ground Zero sites, neither in Manhattan nor at the Pentagon, “A lot of companies that use our products have been working there,” he said.
“They all say that you just can’t grasp the magnitude of destruction until you see it,” said Diane Fort, sales manager with the company’s IAQ Product Group. “We had some customers who went to Ground Zero and stayed for weeks.”
“A lot [of contractors] have come from other parts of the country,” said Shagott. “They said they felt compelled to do something to help.”
CLEANING THE AIRLarge quantities of contaminants were aerosolized after the WTC Towers fell, he said. “There was asbestos and lead in the air. There are hundreds and hundreds of HEPA filters installed in New York or around the Pentagon.”
“An exceptionally large number of commercial and governmental facilities in lower Manhattan and in the nearby areas, as well as residential buildings, were contaminated with large quantities of dirt, concrete dust, insulation materials, asbestos, lead, molds, and other potentially hazardous contaminants,” Shagott explained.
“These materials became aerosolized after the explosions and the collapse of the buildings,” he said. “Once airborne, they infiltrated through blown-out windows or, in many cases, were sucked into these buildings through their fresh air intakes on Sept. 11 and the days that followed.”
The company’s products were used for the cleaning and decontaminating hvac and air duct systems. “We have a lot of contractors going in to totally clean the buildings,” said Fort. “There’s dust, inches thick. Contractors need the air constantly cleaned while they are cleaning.”
Fort added that “ServiceMaster had the main contract for Pentagon cleanup. The Pentagon had sprinkler systems go off,” adding water, smoke, and mold to the complexity of the job.
Abatement Technologies’ products include HEPA-Aire portable air scrubbers (PAS), which are used for air cleaning and deodorization during cleanup and renovation processes; systems used in hospitals to help protect patients and staff from airborne pollutants; air filtration equipment for asbestos and lead abatement; video inspection systems for assessing the contamination in hidden areas; and air purification systems installed into commercial and residential hvac systems, to help prevent recontamination after the cleanup.
People occupying and managing the buildings near the disaster site want the PAS machines back, she added. “Excavation is still going on at Ground Zero.”
Some manual cleaning was performed on extremely large ducts, Shagott said. “Most ducts were put into negative-pressure operation; HEPA-filtered air is then exhausted back into the building.” The equipment’s air agitation feature helped clean the air more quickly and thoroughly.
“We have been able to meet product demand,” Shagott said. “From Sept. 11 on, we have given top priority” to the cleanup related to the attacks. This included diverting product from other customers, most (if not all) of whom said they understood. “This may sound corny, but we felt it was patriotic,” said Shagott. “There have been very few complaints. We have done what we needed to do.
“We are exceptionally proud of the role that Abatement Technologies products — and our customers who use them — have played in the cleanup efforts. We have given and will continue to give the highest priority to these requirements.”
UNDERGROUND RECOVERYAs Ground Zero recovery efforts reached the underground levels of the WTC Towers, the first priority, of course, has been for the recovery of human loss. However, industry insiders knew about the 12 giant York chillers, six floors down, that once cooled some 35,000 WTC occupants. What was their condition, and how could they best be recovered so as to reduce any danger from gas loss and other hazards?
Among the immediate safety concerns for the hundreds of rescue and construction workers at the site was the status of the refrigerant in the large chillers that lay beneath the massive pile of concrete and steel.
“The fear was that heat from inferno-like fires above may turn leaking refrigerant into a highly acidic vapor,” reported refrigerant recovery contractor Hudson Technologies, “or since refrigerant weighs more than air, that the chemical coolant would displace oxygen, making it difficult or impossible to breathe.”
The calls went out first to refrigerant provider DuPont and York International, manufacturer of the chillers as well as hvac service contractor for the World Trade Center. Both companies then called Hudson Technologies for handling the refrigerant recovery-related issues.
This would be no simple, straightforward recovery.
“Within days of the Towers’ collapse, several attempts were made by Ground Zero crews to reach the giant chillers, including using remote cameras, but damage to the surrounding area was too severe and dangerous,” stated the contractor.
It wasn’t until two months later that Ground Zero engineers and the Hudson/York team, fronted by New York City firefighters, worked in knee-high water and sledge-hammered their way through concrete walls and steel doors. Then they reached a mechanical room and examined some of the chillers — six stories down. Large slabs of concrete from above had crushed many of the chillers, but so far two have been found intact. They still contained refrigerant gas.
York and Hudson were charged with writing the engineering specifications for the gas recovery, under the supervision of the New York City Department of Design and Construction (DDS), which is overseeing all the work at Ground Zero. The Hudson/York team worked closely with the Environmental Protection Agency, the Port Authority of New York & New Jersey, Bovis Construction, and the DDS to develop the parameters, strategy, and tactics for recovering the refrigerant. Safety was paramount.
DAYS OF RECOVERYWith a New York Fire Department-approved emergency evacuation plan in place, Hudson rolled one of its 40-ft tanker trucks into Ground Zero, parking it just a few feet away from the upright cross formed by a falling steel beam, which has stood as a symbol of prayer and remembrance of the victims.
The team snaked about 700 ft of hose from the tanker, down five stories to a hole in a double slab of concrete just big enough to crawl through that was created earlier by the firefighters. From there, the team entered a stairway in pitch-black darkness. Stepping in knee-high water, they maneuvered around broken pipes, fallen concrete, and other debris, down one more flight to one of the mechanical rooms.
“The team was equipped with flashlights, but the darkness was so intense that it quickly swallowed up any light,” reported the contractor. “Hooking up the hoses to the York chiller valves became as much a touch and feel as actual sight, since the bottom of the chiller was submerged under water.”
The team described the entire experience as “very eerie and chilling.” As one of the technicians recounted later, “The equipment room resembled a war zone cast in complete darkness.”
The team worked over three days, Dec. 4-6, from 7 p.m. to 5 a.m., when excavation crews above ground were not working. The team was outfitted with detectors that measured refrigerant, carbon monoxide, hydrogen sulfide, and oxygen in the air. Each person carried a supply of oxygen while underground.
The recovery was completed according to plan. The Hudson/York team may be called in again if other units are discovered, as the excavation work continues and other mechanical rooms with chillers are made accessible.
Publication date: 01/14/2002