NYC-WTC_000218466

NYC 9/11 Public Portal Document

For Windowsills: 250 pg/fV For Floors: 40 pg/lV For Exterior Concrete or Rough Surfaces: 800 pg/fV

Although the lead-in-dust samples collected at P.S. 234M were not collected in response to lead abatement, the same thresholds are used since no other regulations or standards are applicable to this project.

Sampling Methodology ATC provided all laboratory analytical services in support of this limited inspection. ATC is certified by the New York State Department of Health’s Environmental Laboratory Accreditation Program to perform lead and related analyses of environmental samples (Laboratory ID Number: 10879). The laboratory utilizes the United States Environmental Protection Agency analysis method number SW846-7420 and the National Institute of Occupational Safety and Health method number 7082M.

The lead-in-dust samples were obtained by gently wiping a pre-measured surface area with non-alcohol moistened towelettes. ATC’s representative wore disposable gloves; a new glove was worn with each new sampling procedure, and care was taken to avoid contamination of the towelette and collection vial. Towelettes were then placed into 50ml plastic vials and immediately sealed. The chain of custody form was completed and documents the measurement of the area sampled.

Results of Dust Wipe Sampling Thirty-three (33) dust wipe samples were collected from areas indicated to ATC. Laboratory analysis indicates that all dust wipe samples collected from the indicated areas contain lead on floor , windowsill and exterior concrete or rough surfaces below the guideline level of 40 pg/ft’, 250 pg/ft^ and 800pg/ft^ respectively. See laboratory report and chain of custody for more details.

Limits of the limited dust wipe sampling Dust sampling was conducted at NYC-BOE request. The results of this report are applicable for the time the testing was performed. If questions arise concerning lead content in or on components and/or locations not tested by ATC, then additional testing services should be procured. ATC makes no representation or wananty concerning the standards and specifications provided in the HUD Guidelines and the NYC-BOE protocol.

P.S 234M STY March 25, 2002

CITY_21MC100_002878862

NYC-WTC_000218468