At Burned Bank Tower, Safety Is a Goal With Many Obstacles

Dressed for battle in double polyethylene suits (one over the other), full-face air-purifying respirators, chemical-resistant gloves, hard hats, safety goggles, safety boots and water-resistant over-boots, about 300 workers have been cleaning the former Deutsche Bank building at 130 Liberty Street for much of this year, a few steps ahead of deconstruction crews.

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Their goal is to rid the building of any visible speck of dust, to leave one-acre floors so clean that leaf blowers cannot kick up enough residue to register on air-quality monitors. The dust, blown in from the collapsing World Trade Center, contains enough asbestos, dioxin, lead, quartz, chromium, manganese and polycyclic aromatic hydrocarbons to be of concern. So the abatement crews work in areas that are sealed behind windows, plywood and polyethylene sheets, where the air pressure is kept lower than outside to prevent contaminants from being expelled.

They fight a modern disaster with some very old tools — toothbrushes, pipe cleaners and scrapers — cleaning all the way down to the tightest crevices and narrowest screw threads. They do not even try to clean porous objects, but treat them as if they contain asbestos, and many of them do. These are packaged in plastic bags that go into plastic-lined boxes that go into two more plastic bags and then go to landfills in Pennsylvania, Ohio and West Virginia.

Their work was suspended Aug. 18 by a fire that killed two firefighters and brought another halt to the tortuous deconstruction of 130 Liberty Street, opposite ground zero. The fire, and the resulting deaths, can be blamed on many things other than the decontamination procedures: Careless smoking. Inspections that were never done. No special firefighting plan. And, most elementally, a disconnected standpipe.

There seems to be little question, however, that decontamination barriers contributed to the disaster. The fire was fueled by plywood and polyethylene sheets that isolated floors where potentially hazardous dust was being cleaned. These barriers complicated firefighters’ movements and may have blocked their escape. And exhaust fans may have drawn the fire downward, endangering the temporary firefighting command center.

All of which invites the question: How can the rest of the 41-story building, now down to 26 floors, be razed in a way that protects the environment, the workers, the building’s neighbors and emergency personnel? And this question, too: Would any revision be an acknowledgment that environmental regulators — federal and state — went too far in the first place?

While defending the basic decontamination approach, the federal Environmental Protection Agency acknowledged yesterday that changes were necessary.

“Modifications to some of the plans will need to be made to address concerns expressed by city emergency responders,” Alan J. Steinberg, the agency’s regional administrator, said in a statement. “Such modifications can be made without compromising in any way the required protective plans and regulations.”

The polyethylene used to keep barriers airtight could be replaced by a fire-retardant material. Stairway barriers could be constructed so they can be broken much more easily in an emergency. The air pressure systems — in essence, exhaust fans — could be controlled by a master switch that would allow them to be shut off at once.

Mayor Michael R. Bloomberg defended the E.P.A. yesterday, asking about the consequences if it had not gone far enough in regulating the site.

“There has been, for the last five or six years, a focus on making sure that the public — the air the public breathes — is safe,” Mr. Bloomberg said in his weekly radio interview on WABC. “And the E.P.A. has set some very reasonable — strict, but reasonable — rules. In their judgment, this is what’s required to keep the public safe. I’m not an expert, they are the experts, and you know what would happen to them if they relaxed their rules. There’d be all sorts of criticism and you remember Christie Whitman going through all of that craziness.”

Mrs. Whitman, the former E.P.A. administrator, came under intense criticism for characterizing the air in Lower Manhattan as “safe to breathe” less than a week after the attack.

Rather than commenting directly on the regulations, the Lower Manhattan Development Corporation, which owns 130 Liberty Street, has instead made a point of noting that more than 700 tests of the air in and around the building, which has been open since the fire, have shown what are considered safe levels of asbestos, particulate matter, metals and organics.

Workers first enter the sealed floors through decontamination chambers with a series of air locks.

They deal with two types of contaminants: those that were in the building before Sept. 11, 2001, (asbestos in floor tiles, caulking and sealants; mercury in light bulbs and thermostats; lead in computer terminals; polychlorinated biphenyls in fluorescent fixtures) and trade center dust.

Building fixtures with contaminants are cleaned and removed. What remains is divided between nonporous elements and porous materials (wallboard, carpeting, ceiling tiles, fireproofing), which are considered uncleanable.

The nonporous structure — steel, concrete and glass — is then cleaned of dust.

After a section has been cleaned, regulators conduct a visual inspection. They have required that entire sections be recleaned when they have spotted dime-sized bits of dust or debris. After a floor passes the visual test, inspectors with leaf blowers attempt to stir up residue.

“The contractors haven’t been happy about this level of rigorousness, but it’s been working,” said Pat Evangelista, the E.P.A.’s World Trade Center coordinator.