NYC-WTC_000195194

NYC 9/11 Public Portal Document

of its past use in accordance with the Asbestos Hazard Emergency Response Act (AHERA), for determining the effectiveness of asbestos abatement in schools. Modified-aggressive air sampling w was also used because it is more representative of long-term trends of typical household activity such as those expected within the study building.

While there is a greater potential for overloading under aggressive sampling conditions, this test is representative of a worst case scenario. Modified-aggressive air sampling, however, has less of a w potential for overloading and is typical of household activity patterns. (Difficulties associated with sample overloading are discussed in detail in Section 3.8 below.)

Other post-cleanup sampling efforts were implemented to evaluate the efficiency of the cleaning w of the HVAC systems within the two commercial units included in the study (Chiropractor’s Office, Mattress Store). Post-cleanup air samples were collected in close proximity to the HVAC return ducts and analyzed for asbestos, MMVF, alpha-quartz and lead. w 3.5 Sampling Supplies and Equipment V

w Table 5.0 specifies the supplies and equipment required and utilized to collect samples, as * described in the QAPP ' ’

Table 6.0 specifies the micro vacuum equipment and the National Air Duct Cleaners Association (NADCA)-recommended method for sample collection that was used.

Table 7.0 specifies the air sampling equipment that was used.

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” The QAPP is presented within Attachment G. 29

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