Chain of custody form, Trinity Place samples, Oct 2001

NYC 9/11 Public Portal Document

0912812e0l 10:14 6315803195 ENVIROSCIENL C•NSLTAN PAGE 03

American Stodr Facdhnge,28 September 2001

centimeters) to produce the asbestos air concentration. The NIOSH 7400 or 7402 methods used by OSHA to evaluate worker exposure results in values of fibers per cubic. centimeter. Fibers greater than 5 micrometers in length and greater than 0.25 micrometers in diaw.ter are counted. Structures counted in AHERA include the fibers in the NJOSH OSHA approach and includes much smaller. structures. So the AHERA air concentration presented in the attached tables are more protective than the NIOSH OSHA approach

Samples that met the U.S. EPA ARERA clearance criteria of 70 structures/square millimeter are considered acceptable and are considered safe for reoccupancy.

The 9s' floor has tluee samples (Room, 909. Cubical 49, and Cassaleggi room) that exceed the U.S. EPA Alx'ERA clearance criteria of 70 structures/square millimeter and one that approaches the clearance criteria ( Cubical 52). Cubical 39 has a value of 37.88. These results are less than the OSHA PEL of 0.1 fibers per cubic centimeter.

We believe the asbestos in the air in these areas is due to the catastrophe and we do not believe that the asbestos was from the 22 Thames huilding because of the residue from the explosions and collapse was found in significant quantities on this floor and because the other results in 22 Thames and 86 Trinity Place are so low. tither floors such as the 5'" floor also had significant quantities of the residue from the explosions and collapse. On September 23, 2001, we recommend that the floors in 22 Thames that had not been tested be tested. This sampling was completed on September 24i' 2001.

Outdoors samples were collected on the 4s' floor, and the Be floor. These samples were all less than detectable limits. These outdoor samples may be compared with the U.S. EPA collected asbestos air monitoring locat;ons Lower Manhattan that are presented on iwwww.epa.gov1epahame/dalamap02,hrstn.

Asbestos bulk samples were collected on September 20'' and September 24a'. Dust samples were collected from exterior window ledges and different sites where material was available inside the building. All samples collected are not considered asbestos contaltirg material since they contain less than one percent asbestos. The Asbestos bulk sample results are presented in the attached tables.

The asbestos clean up must be conducted by New York State and U.S. EPA certified asbestos abatement contractors and workers. The general cleaning protocol once gross debris has been removed is to HEPA vacuum, followed by an amended water wash, followed by HEPA vacuuming. Porous surfaces such as carpets, firm#tire, ceiling tiles (and support grids), office partitions, and other soft goods must be evaluated for the feasibility of cleaning. if surfaces can not be cleaned they must be discarded. The electrical equipment must be evaluated and specially cleaned or discarded.

The asbestos cleaning started with the floors most needed by the American Stock Exchange and proceeded to other floors on a priority basis. Asbestos fibers frotn outside the building and from the 9* floor of 22 Thames have not appeared to migrate to the other floors because the samples collected on later days show virtually all zero counts for structures per millimeter squared or structures per centimeter squared.

The lead in air samples were collected from areas considered representative of the building. Only

area

one sample to

was collected from each

accelerate

th e

lead building screening

process.

in The

air results are presented is the table below.

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a

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