NYC-WTC_000196109

NYC 9/11 Public Portal Document FR: ’.5;.'.? FAX 212 233 536" 233 S'.dg Mgmt a002 ♦ 12n 672 ^725 fh litkiff Grm l«/ll/ll 13:33 P.002/665

dvanced Environmental Corp.

October 12, 2001

Mr. Crag Murphy Director ofProject Devalapment The Witkoff Group 220 £851:42“* Street New Yeti; NY 10017 Re: Asbestos Air Monitoring, Various Areas, 233 Broadway, New York, NY Dear Mr. Muroto-

On October 11, 2001, Advanced Environmental Corp. pezfORsed air monitoring at die above locsdoo. Samples were collected on floors specified by building management to document the asbestos fiber concentration levels of die ambient air flom Tepresantadve areas of the building. Six (Q samples were collected and analyzed using the Trsnsmission Electron Microscopy (TEM) method according to the EPA AHERA protocol TEM with energy dispersive X-ray analysis is an analytical method that enables a fibers chemical compcsitioa to be identified and thereby overcoming the non- specificity of PCM analysis. This fiber specific protocol is generally utilized to determine clean air following a 'T^e",abat69ient project TEM pmple analysis detects filter loads (the number of structures detected per square milliroetcr of coOretion media ruzfiux) which, if less than or equal to EPA-AHERA release criteria Of 70 structures per square nuTinieter (sZmi^ detomine whether or not be area is safe for rc-occupancy.

The TEM san^lcs were collected in the lobby area, floors 5,12, Id, and 2$. The sarqjles and the results isan be found in Appendix A, Listed is the sample identification number, area analyzed, sample volume, structure counts, analytical sensitivity, and the concentration of asbestos. As a review of Appendix A shows, no asbestos Structures were detected on any sangiles collected. ' m conclusion, the TEM sample data show acceptable concentrations of fibrous noateiiaLs in the ambient stir.

Ifyou have any questions or need finther clariflcarioa on ah sampling methodology, please call me.

lidward Nimath Principal 1135,005 X^:pi,M«wrt>daaht=Wt«ni,.*«i*o8OM b«»y - O-11 <« I win BV nw

G ITY_D EP_WO RB Y_C ANN ATAS U B P_000007239

NYC-WTC_000196109