Corrupted document file, WTC site, Oct 2001

NYC 9/11 Public Portal Document

Recommendations for Sampling Buildings with Residential Use—CONCEPTS for use near WTC DRAFT ATSDR/DHAC Version 1, Sept 25, 2001 '

1. Focus/Priorities of sampling The selection of priority residential areas should be decided upon by NYC DOH, or by someone else on the scene with the concurrence of NYCDOH. Selection needs to be based on worst-case scenario(s) first, which will likely involve a visual determination (e.g., visible dust in lobby area, broken windows, dust along roadways and sidewalks). Likely worst-case residential areas would seem to'be: A. Residential areas closest (adjacent) to the WTC B. Residential areas where contaminant track-in from debris fallout or from Search/ Rescue/Removal vehicles have spread dust

Once a few worst-case areas have been selected, then'the suggested sampling approach (see II) can be pursued. If results of sampling in worst-case locations indicate no contaminants present at levels of health concern, then residential sampling should be considered only on a case-by-case basis (e.g., citizen complaint followed by a visual inspection).

If results in worst-case locations show contaminants at levels of concern, a thorough cleaning (these instructions need to be developed) should follow and the locations should be re-sampled. If the post-cleaning round of sampling indicates successful remediation, then prior to sampling any additional residential locations (e.g., residential areas that also meet “worst case” or those on the tier below “worst case”) a thorough cleaning should be conducted. If post-sampling confirms that contaminants are below levels of health concern, then as other residential areas are cleaned, post-cleaning sampling should only occur periodically as a quality assurance check of cleaning effectiveness.

II. Sampling Approach ATSDR suggests that sampling should focus on asbestos (PCM and PCMe), respirable silica, and inhalable and respirable airborne particulate matter (TSP, PMIO, and PM2.5). Sampling should focus on common/high traffic areas of the building (e.g,, lobbies, front entryways). These areas should also be representative of worst case conditions for contaminant track-in.

If the building is unoccupied, aggressive indoor air sampling should be conducted. If the building is occupied, air sampling should be conducted with the building HVAC system in continuous operation.

Floor dust sampling should be conducted using EPA’s Environmental Response Team (ERT) SOP (HEPA vacuum). Location of sample and area sampled are required information to be collected. Samples should be analyzed for asbestos (via TEM as the detection limit for PLM is 1%); and respirable silica.

III. Action Levels Action levels will be developed for silica, PM, and vacuum dust samples. A format similar to the “ATSDR/CDC Asbestos Air Action Levels for World Trade Center Response” is anticipated.

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