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

5.4 Mercury (Gas/Vapor)

Real-time monitoring for mercury will be performed utilizing a Lumex RA 915-1- direct read instniment. The readings will be included with the daily download of sample collection data.

The Lumex RA 915-1- will be utilized to obtain detection levels below established site air contaminant criteria. At a minimum, mercury readings will be taken twice a shift (e.g., 8-hour period) at each of the eight (8) fixed air monitoring locations situated in the immediate vicinity of the 130 Liberty Street property. This includes four (4) ground level stations and four (4) floating stations on the scaffolding. At the discretion of the Environmental Consultant and as daily site conditions may dictate, additional mercury readings may be taken.

5.5 Mercury (Total Elemental)

A separate sampling and analysis method is required for mercury, as field studies have indicated that atmospheric mercury is generally greater than 95% in the vapor phase. An iodated carbon trap will be analyzed for total elemental mercury (particulate associated/vapor) using cold vapor atomic fluorescence (CVAFS). The carbon trap is a proven and sensitive method for detecting trace ambient levels of atmospheric mercury. To collect the mercury sample, a low volume pump will be attached to the carbon trap and set at a flow rate of approximately 0.4 liter per minute.

5.6 Respirable Dust and Crystalline Silica

Respirable dust and crystalline silica sampling will be performed according to NIOSH Method 0600 protocol with analysis following NIOSH Method 7500 (XRD).

5.7 Semivolatile Organics

5.7.1 PCDDs/PCDFs and PAHs

Each site will have two (2) General Metal Works (GMW) model PS-1 high volume air samplers to collect 24-hour samples of PAHs and Dioxins/Furans following USEPA Method TO-13A and TO 9A, respectively. Method TO-13A and TO-9A use the PS-1 samplers to draw air through a sampling train consisting of a 102 millimeters diameter microquartz filter first to collect the semivolatile particulates and then a glass cylinder holding a polyurethane foam (PUF) plug (1 inch of XAD-2 adsorbent resin is used in the middle of the PAH sampling media) to collect the semivolatile vapors. The entire sampling train (filter, XAD-2, and/or PUF plugs) are extracted together and analyzed for speciated PAHs and D/Fs compounds using gas chromatography/mass spectrometry. The samplers will be set to mn at approximately 200 liters per minute resulting in a total air volume of 288 m^ over the prescribed 24-hour sampling period.

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