Chain of custody form for DEP environmental samples, 2001

NYC 9/11 Public Portal Document

EPA applied up to two cleaning methods in each of thirteen residential units, and up to five cleaning methods in each of two commercial units. The eleven cleaning methods tested are presented below;

1. Residential quality upright vacuums and shop vacuums. 2. Residential quality upright vacuums and shop vacuums with the addition of an Air Filtration Device (AFD). 3. HEPA-filtered upright and shop vacuums. 4. HEPA-filtered upright and shop vacuums with the addition of an AFD. 5. Industrial quality HEPA-filtered vacuums. 6. Industrial quality HEPA-filtered vacuums with the addition of an AFD. (This cleaning method was used in both residential and commercial units.) 7. Wet wiping of all horizontal and/or vertical surfaces with soap and water. 8. Carpet cleaning. 9. Standard cleaning procedures used by professional duct cleaning companies for the cleaning of air conditioning (A/C) systems, ducts and related equipment. 10. Use of water only for wet wipe of horizontal and/or vertical surfaces. 11. Scope A cleaning procedures developed by EPA and New York City for the cleaning of units in lower Manhattan.

Determination of which cleaning method would be studied in each rental unit was based on the apparent level of impact that unit had endured as a result of the WTC collapse. EPA developed a set of four tests to evaluate cleaning methods in the rental units. The tests were assigned based upon readily observable impact by WTC dust, and prescribed six of the eleven cleaning methods to be used to respond to each level of impact. Up to five different cleaning tests were tested in each residential and commercial unit. Factors related to level of impact included directional exposure to ground zero and location of the unit in the building.

At project commencement, a visual assessment of the level of impact each rental unit had sustained was performed. This assessment was utilized to assign each rental unit to an applicable cleaning test. The assignment process was modified to ensure that each of the cleaning methods was applied (tested) in units that had experienced both low and high levels of observable impact.

The effectiveness of the cleaning methods was evaluated through the collection and analysis of pre-cleanup and post-cleanup samples, and through comparison of the resulting analytical data to the COPC, to determine if the cleaning method achieved health-based screening levels. The COPC evaluated in this study were: asbestos in air by PCMe, lead in air and settled dust, dioxin in air and settled dust, PAH in air and settled dust, fibrous glass (MMVF) in air, and alpha-quartz in air.

Data was also evaluated from other compounds that do not have health-based benchmarks established in EPA’s COPCZBenchmark Report. These included asbestos in air by PCM and TEM AHERA, asbestos in settled dust, calcite in air and settled dust, gypsum in air and settled dust, cristobalite in air and settled dust, tridymite in air and settled dust, fibrous glass (MMVF) in settled dust by wipe sampling, alpha-quartz in settled dust by wipe sampling and total settled dust. After the initial cleaning of each unit, the OSC reviewed the established cleanup criteria, reviewed the analytical results, and provided direction as to which units required additional cleaning. In the event that it was determined that a unit did not achieve the primary clearance criteria, it was

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