HVAC Dust Sampling Procedures, WTC Dust, Oct 2001

NYC 9/11 Public Portal Document

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

V 3. A HEPA vacuum shall be on-site for clean-up, if needed.

4. Dust may be collected from any visible deposit. Frequently, dust will be more likely to accumulate on horizontal surfaces, although ^s may not always be the case.

5. Sample collection and analysis

Bulk samples. Bulk dust samples may be scooped or scraped into a sealable container using an appropriate sampling device. A minimum of 20 grams of sample will be collected. Wipe the device with a clean, wet cloth between samples to prevent cross-contamination. Wipe the exterior of the sample container to remove excess dust. Label the container with the sample identification. At minimum, for each sample the date, building name, and specific location of the sample, including whether or not the sample is located upstream or downstream of the air filters, shall be recorded.

6. Completion of sampling

The Environmental Professional shall repair or seal any interior/exterior duct insulation disturbed as a result of sample collection.

At the completion of sampling, the Environmental Professional shall wipe the outside of his/her respirator with a clean, wet, disposable cloth and shall place the respirator into a S clean, sealed plastic bag. Clean any suspect debris or contamination resulting from the sampling activities using a HEPA vacuum or wet wiping methods. All wiping cloths, disposable protective suits and gloves, and drop cloths shall be placed into a sealed polyethylene bag for proper disposal.

7.0 Post-cleaning Visual Inspection

Cleanliness verification shall be performed by the evaluation team consisting of a HVAC/Electrical Professional and an Environmental Professional as described in section 5.0 of this document after cleaning of one or more ventilation system components has been completed.

Following cleaning, the Environmental Professional shall ensure that all interior ventilation system components that were subject to the cleaning procedures are visibly clean. An interior surface will be considered visibly clean when it is free from non-adhered substances and debris.

To determine whether a surface if visibly clean, a thorough and comprehensive visual inspection and assessment of all cleaned components shall be performed in accordance with visual procedures established in items 6.5.2.1 and 6.5.2.2 of this document. In order to observe locations that are difficult to clean, additional access openings shall be installed as needed to conduct a comprehensive post-cleaning visual inspection.

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NYC-WTC_000140476