HVAC monitoring addendum to scope of work, August 2002

NYC 9/11 Public Portal Document

ADDENDUM #2 World Trade Center Dust Cleaning Program Monitoring Contract Scope of Work

- the depth and location of dust on ducts and fan housing (i.e., on interior bottom, top and sides of ducts) - visually estimated percentage of surface area with suspect WTC-related dust whether or not there are materials that are likely not associated with WTC- related dust such as building-related asbestos-containing materials, animal carcasses, delaminating lining material, visible mold growth, water damage, fecal matter, feathers or other evidence of animals, etc.

Historical Assessment

The evaluation team shall attempt to describe any other available information from site occupants or building managers, such as the known status of system operating conditions at the time of the WTC collapse, ventilation system maintenance (i.e., cleanings, filter changes, or replacement since the WTC collapse).

Based on these assessments, to the best of his/her ability the Environmental Professional will state a general impression of the overall cleanliness of each component, and whether or not it appears to be impacted by WTC-related dust.

6.5.2.3 Environmental Sampling Procedure

If the evaluation team determines that the ventilation equipment appears to have been impacted by WTC-related dust, cleaning will be recommended and environmental sampling will not be required. This information shall be included in the HVAC system evaluation report. The HVAC system evaluation report must be sent to EPA electronically in PDF format.

In the absence of environmental sampling that indicates otherwise, WTC-related dust shall be assumed to be an asbestos-containing material and cleaning procedures shall be performed in accordance with procedures for asbestos decontamination (see section 5.0).

If dust or debris is present and it is not apparent that it is related to the collapse of the WTC, a maximum of 5 bulk samples will be collected and analyzed for pH, fibrous glass and crystalline silica. These samples and copies of necessary documentation shall be shipped daily by courier for next day delivery to EMSL Analytical Inc., 107 Haddon Avenue, Westmont, NJ 08108 (Tel: 856-858-4800). This data will be used to determine if the sampled dust is from the collapse of the WTC. Dust will be considered WTC-related if: pH is 9 or above; fibrous glass content is between 30 and 40 % and crystalline silica content is 5% or greater. Laboratory data will be reported back to the Monitoring Contractor and shall be included in the HVAC system evaluation report. The HVAC system evaluation report must be sent to EPA electronically in PDF format.

Sampling Procedures

1. Sampling of interior dust may only be performed by the Environmental Professional.

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