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

8.1.1 Target Air (luality Levels

Any 24-hour PMio and PM2.5 value in excess of the Target Air Quality Level will be considered an “exceedance” and the actions described below will be taken.

During the first week of sampling, any sample of an analyte, other than PMio and PM2.5, in excess of 3 times the Target Air Quality level for that analyte unless superseded by a USEPA Site Specific Trigger Level, will be considered an exceedance and the actions described below will be taken.

Following the first week of sampling, a cumulative average will be established based initially on the first week’s results, to which will be added daily values as results are received from the laboratory. A cumulative average value for any analyte other than PM2,5 and PMio in excess of the relevant Target Air Quality Level will be considered an exceedance and the actions described below will be taken.

Exceedances of an established Target Air Quality Level for any analyte calculated as provided above will result in an evaluation of engineering controls and work techniques in the source area. The evaluation of engineering controls and work techniques shall determine whether: (i) negative pressure is being maintained in active work areas at the required levels (ii) there are breaches in the containment in active work areas, and (iii) there are any visible emissions from the containment areas. In addition, the evaluation will consider other potential sources contributing to or causing the exceedance.

8.1.2 USEPA Site Specific Trigger Levels

Any 24-hour value (eight-hour value in the case of asbestos and silica) in excess of the USEPA Site Specific Trigger Level will be considered an “exceedance” and the actions described below will be taken.

Exceedance of USEPA Site Specific Trigger Levels will result in a stoppage of work associated with the exceedance until an evaluation of emission controls is performed and corrective action is in place. The USEPA Site Specific Trigger Levels are applicable to individual sample results. If any of the individual sample results exceed an USEPA Site Specific Trigger Level, then notification must be made to the USEPA Region 2, NYCDEP and NYSDOL as well as LMDC and LMCCC. Work will be reinitiated once the USEPA Region 2 has agreed (and NYSDOL during the Abatement Phase in the case of asbestos exceedances) to the corrective action(s) proposed to prevent the potential for exceedances in future work and such corrective actions have been implemented. The only exception to the work stoppage requirement will be for an exceedance of the USEPA Site Specific Trigger Level for PM2.5 at one of the off-site roof top locations. If the USEPA Site Specific Trigger Level for PM2.5 is exceeded at an off-site roof top location, regulator notifications as described above will be made and an assessment, with the active involvement of the USEPA, will be performed to determine if the exceedance was due to an off-site or regional condition unrelated to 130 Liberty Street work If the assessment

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