NYC-WTC_000231976

NYC 9/11 Public Portal Document

Section 2 - Ambient Air Monitoring Program Revision No.: 0 130 Liberty Street Deconstruction Plan Date: September 7, 2005 Lower Manhattan Development Corporation

2.0 SAMPLING SITES 2.1 Network Design

Due to the unique circumstances associated with this deconstruction project three different types of monitoring sites are recommended for inclusion in the active monitoring network as follows:

• On-Site Street Level Stations- These locations essentially represent sidewalk settings situated around the perimeter of the building. Four (4) such stations will be included in the monitoring network as shown in Figure 1.

• Off-Site Elevated Stations- The proposed network will make use of monitoring sites in place at elevated locations above street level. It is LMDC’s intention to include four (4) such stations in the monitoring network. All four (4) of the proposed off-site rooftop sampling locations are identified in Figure 2.

• On-Site Scaffolding Elevated Stations- Air monitoring stations will also be located on the four sides of the scaffolding. These four “floating” monitoring stations will be re­ located on the scaffolding in ten floor increments (e.g. floors 30, 20 and 10) as the deconstruction work progresses from the roof level to ground level. Four (4) such stations will be included in the monitoring network (one on each side of the scaffolding) as shown in Figure 2. If Phase I Asbestos and COPC Abatement proceeds below these scaffold monitors, then additional air monitoring for metals utilizing NIOSH Methods will be conducted at the exhaust manifolds on the lowest elevation of the work area grouping.

2.2 Siting Criteria and Network Operations

The proposed full network will be comprised of twelve (12) stations in simultaneous operation at all times that building abatement and deconstruction activities are in progress, four (4) street level, four (4) off-site elevated, and four (4) on the scaffolding. The placement of sampling stations will follow USEPA and United States Army Corps of Engineers (ACOE) siting criteria for ambient particulate sampling systems to the extent possible. Strict adherence to these criteria at all stations may not be possible given the topography and logistics of the urbanized environment characteristic of the Lower Manhattan setting.

All of the stations will communicate with a central computer housed in the site vicinity. These on-site stations will collect data continuously and telemeter (wirelessly transmit) the data to the central computer. All of the monitoring stations in the immediate vicinity of the deconstruction site will monitor particulate as PMio and PM2.5 on a real-time basis. These data will be logged continuously at each of the sites as well as on the data logger contained in the on site computer center. These data will be stored and archived as 1 O-minute averages for each of the stations.

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NYC-WTC_000231982