NYC 9/11 Public Portal Document
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 fi-om 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 community 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 ft 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/Commercial Buildings where
contamination may still exist
Ambient sampling results do indicate that the source of contamination is disappearing fi-om 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-vacuums) 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.
2
NYC-WTC_000164231
OCR can misread numbers and units. Confirm readings against the page image before using them.