Environmental assessment report, 100 Church Street, April 2002

NYC 9/11 Public Portal Document

• Surface Dust. Between January 11 and March 29, 2002, TRC collected two hundred and forty five (245) dust/surface samples, with samples taken from each floor in a number of locations in the NYCLD space and the HVAC system. These dust/surface samples were tested for asbestos, lead, PCBs, and dioxins. Post re-cleaning dust testing for asbestos in the NYCLD office space is continuing, as explained below in 4.4.1.

Subsequent to ZAR’s initial cleaning activities in the fall of 2001, TRC’s sampling results identified elevated concentrations of asbestos in the carpeting, in one sample taken on the top of a perimeter induction unit, in the computer and printer equipment, and in the HVAC system' Elevated concentrations of lead were also found on some surfaces within the NYCLD space and the HVAC system. As a result of these findings, the NYCLD has replaced the carpeting, computer, fax, printer and copier equipment and painted the perimeter induction units. In addition, extensive re-cleaning of the space occupied by the NYCLD and the HVAC system has been performed. The results of asbestos and lead sampling conducted to date by TRC after the re-cleaning were below target individual sample and geometric mean concentrations. No PCBs were detected in any of the wipe samples. Low levels of dioxin were detected in wipe samples of surfaces within NYCLD space. TRC has conducted a site specific human health risk assessment using the sampling data. The assessment indicated that the concentrations of dioxin do not represent a significant increased risk of cancer (i.e., less than one in one million) to building occupants. The entire NYCLD space is being re-cleaned.

3.0 DESCRIPTION OF TASKS PERFORMED BY TRC This section of the report reviews the tasks perfonned by TRC and identifies the methodologies used in coimection with the environmental assessment of the conditions at 100 Church Street.

3.1 Review of Building Systems Beginning in January 2002, TRC met with ZAR and its consultant, the Ambient Group, Inc., to review and inspect the heating, ventilation and air conditioning (HVAC) system that serves the NYCLD spaces. The purpose of the review was to identify how the HVAC system is configured to ultimately determine how the air is filtered, conditioned and transported to the space occupied

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