E-mails R. Avaltroni 2002

NYC 9/11 Public Portal Document

horizontal surfaces on building facades. For some buildings, building facades facing the street were cleaned while the facades at the rear remained dirty. The observed debris was characteristic of the debris from the WTC collapse of September 11,2001.

Samples collected from various buildings indicated that some of the debris contained asbestos­ containing material. Other samples did not disclose the presence of asbestos, and others were trace or below 1% asbestos. In the absence of sampling data for specific buildings, it is recommended that NYS DOL licensed asbestos contractors with NYC DEP and NYS DOL certified workers perform the clean-up activities. In addition, an independent third party must perform air monitoring during the clean-up activities. This activity is necessary to address concerns by the commuruty of re-entrainment of ambient dust to the interior of buildings. Wet methods and HEPA vacuums will be used for cleaning roofs, terraces, and other outside areas of the buildings.

Costs to Cleanup 250 Buildings

Area Size # Buildings Costs/Sq fl Building Costs

10,000 sq. ft 25 $3 $750,000

5,000 sq. ft 50 $4 $1,000,000

1000-5000 sq. ft 175 $8 $3.500.000

$5;250,000

Air Monitoring Costs $200,000 Facade Cleaning Costs (includes contingency costs) $5,000,000

Total Costs $10,450,000

3) Provide Indoor Cleaning and Sampling for Residences/Conunercial Buildings where contamination may still exist

Ambient sampling results do indicate that the source of contamination is disappearing from the WTC site, since the fires are extinguished and recent sampling results rarely indicate any elevated levels. Federal, State, and New York City agencies are confident that the methods of cleaning (e.g., wet wipes, HEPA-vacuiuns) recommended to residences and commercial buildings are appropriate. However, it is also known that these methods are not always 100% effective, and that there will be instances where apartment owners and commercial facilities will not clean up as recommended.

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