Chain of custody form for DEP environmental samples, 2001

NYC 9/11 Public Portal Document

Chiropractor*s Office - This is a 716 sq. ft. office space with four examination rooms facing the World Trade Center site. All front windows were blown in. Significant amounts of dust were present on all horizontal and vertical surfaces. Floor areas were covered with wall-to-wall carpeting. The suspended ceiling was covered with fibrous tiles. There was a two-foot high void space above the ceiling. The space above the suspended ceiling contained the HVAC system and wood floor joist system for the third floor apartments. This area contained WTC-related and non- WTC- related dust. The space was extremely difficult to clean due to the presence of electrical wires, recessed lighting fixtures, sprinkler systems, and the dry, friable nature of the wood support system. Ceiling tiles, flexible ventilation ducts and office equipment were disposed of prior to cleaning.

Cleaning Method - This unit was the subject of separate tests to evaluate five different cleaning techniques as described below;

Test 4A: Industrial HEPA-filtered vacuums and AFD. Test 4B; Wet wipe all walls. Test 4C; Hot water wet vacuum Test 4D; A/C Duct Cleaning Test 4E; Water only wet-wipe of the bathroom floor and desktop.

Cleaning Results - This unit met the clearance criteria listed in Table 1.0 for each compound after the Test 4E cleaning event except for the lead wipe collected from the bathroom floor.

Supplemental Sampling Activities - Prior to initiating pre-cleaning sampling activities as described below, EPA collected a bulk composite sample from the Chiropractor’s Office. The analytical data obtained from the bulk composite was utilized in identifying COPC concentrations present in settled dust, determining the applicability of regulatory standards, and identifying potential health and safety concerns. The Chiropractor’s Office was selected, based upon visual observation, as being representative of a “worst case scenario” in the study building.

Asbestos Before Cleaning Samples - Two air samples, four micro vacuum samples, and five wipe samples were collected for asbestos. The air samples were analyzed for PCM and PCMe. The PCM results indicate that one sample was above the secondary numeric criterion of 0.01 free and one was below this value. The PCMe results were both below the detection limit and below the primary clearance criterion of 0.0009 S/cc. All four of the micro vacuum samples contained chrysotile above the detection limit. All five wipe samples were also above the detection limit, with chrysotile being detected in all five samples and amosite in two of the five samples.

Post Cleaning Samples (Test 4A) - Three air, four micro vacuum, and five wipe samples were collected for asbestos. The air samples were analyzed for PCM and PCMe; however, none of the analyses could be completed due to overloading of particulate material.

The results of the four micro vacuum samples indicate that asbestos was present at levels lower than those observed before cleaning.

84

NYC-WTC_000145782