WTC residential environmental sampling plan draft, Oct 2001

NYC 9/11 Public Portal Document

iJeanine Prudhomme - wtc residential sampling plan.wpd

V. Residence Selection/Sampling Rationale

The selection of priority residential areas should be decided upon by NYC DOH or the agency of their choosing, or by someone else on the scene with the concurrence of NYC DOH. 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). Worst-case residential areas would include: A. Occupied and unoccupied residential areas closest to the WTC with visible exterior dust/fallout material B. Residential areas further fi-om the WTC, where debris fallout may be tracked indoors C. Residential areas where Search/Rescue/Removal vehicles have spread dust that may be tracked indoors

Once residences are selected, then sampling can be pursued. If results of sampling in worst-case locations indicate no contaminants or respirable particle of present at levels of health concern, then residential sampling should be considered on a case-by-case basis (e.g., citizen complaint followed by a visual inspection).

If results in worst-case locations show indoor contamination/materials present 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 cleaning, 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 prior to any sampling. If post-sampling confirms that contaminants are below levels of health concern, then as other residential areas are cleaned, post-cleaning sampling should occur periodically as a quality assurance check of cleaning effectiveness.

It should be noted that contaminant/materials of concern may vary as the distance of the residence increases fi'om the WTC. Therefore, an effective cleaning regime at one location m^ need to be modified for anther location.

If results in worst-case locations show outdoor contamination/materials present at levels of concern, efforts should be made to reduce these levels and take steps that eliminate transporting them indoors (e.g,. reduce contaminant track in by removing or changing shoes prior to entering residence, use HEP A filters on HVAC systems, inspect/change HVAC filters frequently).

VI. Sampling Approach: I 1. Interior Air and dust sampling should focus on common/high traffic areas of the building (e.g., lobbies, fi'ont entryways) and in a selected number of apartment units where visible dust is and is not reported. These first 2 areas should also be representative of worst case conditions for contaminant/material track-in fi-om outdoors and of fallout deposition. Selecting apartments in the same building should provide information the ranges found in indoor living spaces.

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