NYC-WTC_000232249

NYC 9/11 Public Portal Document

6.0 SAMPLING FREQUENCY 6.1 Background

The background ambient air sampling period will consist of two weeks (14 consecutive calendar days) of monitoring performed immediately prior to the start of abatement activities. Samples will be collected using all seven (7) stations in the monitoring network. All target parameters will be collected over a 24-hour integrated period with the exception of asbestos, PM 10 and mercury utilizing the Lumex insti-ument. PM 10 will be monitored continuously at each of the seven (7) sites while asbestos measurements will be taken at a frequency of once per every eight (8) to twelve (12) hours at each of the sites.

6.2 Phase I - Asbestos and COPC Abatement Phase

During Phase I (abatement phase) air monitoring will take place at all seven (7) stations each day. During the first three (3) days only of Phase I work, samples will be collected for semivolatile organics to include PCDDs/PCDFs, PAHs and PCBs. After this first three (3) day period, samples for semivolatile organics will be reduced to a single location per week employing the seven (7) station network. More specifically, samples will not be collected using all seven (7) stations each day; rather a single set of samples will be collected each day at a single station in the network. This sequence will be repeated each day using a different station each day until all of the seven (7) stations have been used. In this manner a set of samples will be collected at each location every seven (7) days. The schedule will be repeated until project completion.

The semivolatile organic samples collected employing this weekly sampling frequency will not be processed for analyses; rather they will be placed in archival storage at the laboratory. A single set of samples will be selected from each sample set representing seven (7) days to undergo analyses for PCDDs/PCDFs, PAHs and PCBs. The station with the highest 24-hour average PM 10 concentration (ug/m3) recorded with a collocated organic sample each week will be selected for semivolatile organic analyses.

A summary of sampling frequencies on a target parameter specific basis applicable to the abatement phase of the deconstruction program is provided in Table 3.

Table 3. Phase I -Abatement Phase Sampling and Analysis Summary Location Parameter(s) Sample Frequency Analysis Method Site Area Mercury (vapor/gas) Each Day Lumex, portable mercury analyzer Site Area Visible dust emissions Each Day Visual observation Ground/Street 1. Asbestos Each Day, asbestos is 1. TEM Eevel 2. Silica sampled each work shift 2. XRD (4 T.ocations) 3. Metals 3. XRF

4. PCDDs/PCDEs Each Day (24 hr. Basis) 4. TO 9 A (HRGC/HRMs) 5. PAHs 5. TO 13 A (GC/MS) 6. PCBs 6. TO 4 A (GC/MS)

L2005-149 (051205) 1 5023623.2

C ITY_D E P_WO RB Y_C AN N ATA_SU B P_000114896

NYC-WTC_000232265