NYC-WTC_000199756

NYC 9/11 Public Portal Document

F Jessica Leighton - RA_sitrepO1~21 .wpd Page 5

10.75 ug/m\ o Wall Street - 24-hour average concentrations for this period was 13.75 ug/m^. o All readings below the National Ambient Air Quality Standard for PM2.5 (65 ug/m’).

NYC / ER (Jan 18) - Particulate Monitoring (TEOM PMio)

o WalLSfreet - 24-hour average concentrations for this period was 25.73 ug/m\ o All readings below the National Ambient Air Quality Standard for PMio (150 ug/m’y

NYC / ER (Jan 18) - Particulate Monitoring (Dataram)

o Particulate levels noted at two locations (Stations N and R) were below the OSHA TWA. o Instruments operated approximately 5/2 hours. o Measurements were not conducted at Station L due to an equipment malfunction. o Station N values ranged from 0.0 to 83.2 ug/m’ with an average of 25.0 ug/mL o Station R values ranged from 0.0 to 129.4 ug/m^ with an average of 30.5 ug/mf

NYC / ER (Jan 19) - Particulate Monitoring (Dataram)

o No particulate measurements were conducted at Stations L, N, and R due to the weather conditions.

NYC / ER (Jan 20) - Particulate Monitoring (Dataram)

o Particulate levels noted at two locations (Stations L, N, and R) were below the OSHA TWA. o Instruments operated approximately 6 hours. o Station L values ranged from 0.4 to 63.1 ug/m’ with an average of 24.5 ug/m’. o Station N values ranged from 0.0 to 118.9 ug/m^ with an average of 17.5 ug/m\ o Station R values ranged from 9.4 to 244.7 ug/m’ with an average of 30.3 ug/m\

NYC / ER (Jan 18) - Volatile Organics (Mobile Laboratory)

o Aside from one compound detected at one location, volatile organic compounds were not detected above the detection limit (20 ppbv) in any of the four samples collected (Washing Tent, Austin Tobin Plaza, North Tower, and South Tower), including in the debris area at ground level.

NYC / ER (Jan 19) - Volatile Organics (Mobile Laboratory)

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NYC-WTC_000199760