NYC 9/11 Public Portal Document
Mr Rajappan Radhakrishnan — NYC DEP
21-23 Thames Street Variance Request
Airtek Project 05-0701— June 9, 2005
I* Project Monitoring:
Project Monitoring: Throughout the decontamination activities, project air
monitoring will be conducted in addition to the Perimeter Monitoring described
above. Project Monitoring will be conducted in strict accordance with RCNY
Title 15 Chapter 1, Section 1-41 to 1-45, with the exception that all sample
analyses will be by TEM.
Clearance Testing: Aggressive area clearance testing for asbestos will be
conducted for all work areas by TEM. Aggressive clearance testing for metals
will be conducted by NIOSH 7300.
Clearance Criteria:
Clearance testing for asbestos will be acceptable when all samples for a given
work area meet the 70 structures per square millimeter TEM standard. Clearance
testing for metals will be acceptable when all samples meet the following criteria:
Antimony 250 ug/m3
Barium 250 ug/m3
Beryllium 1.0 ug/m3
• Cadmium 5.0 ug/m3
Chromium (III) 250 ug/m3
Copper 500 ug/m3
Lead 25 ug/m3
Manganese 100 ug/m3
Mercury 12.5 ug/m3
Nickel 50 ug/m3
Zinc 1,000 ug/m3
Exterior.
The exterior of the building was decontaminated as a part of the NYC DEP
Building Exterior Cleaning Program following 9/11/01. Airtek's visual inspection
of the façade indicates that it is advisable to conduct low-pressure power washing
prior to initialing demolition activities. The exterior of the building will be
cleaned in accordance with the NYC DEP WTC Dust/Residue Roof & Façade
Cleaning Procedures (attached).
Interior:
• Phase 1— Access Facility:
NYC-WTC 000127797
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