Site identification record, 74-90 Church Street, Oct 2001

NYC 9/11 Public Portal Document

November 14, 2001

To: Brian Clarke, NYCHA CC: Laurie Hurst, Boston Properties From: Gerard Baril, Marta Lutsky, Ambient Group

Re: 90 Church St. — Summary of Environmental Sampling Results

Ambient Group has performed environmental sampling at the above location with the following results presented below. See appendix A for sample locations by floor.

1. Asbestos — Ambient performed dust characterization testing on floors 4-6 and 8-12. Ambient took 7-11 samples on each floor. Twenty-eight (28) of the fifty-five (55) samples taken, registered positive results for asbestos. There were positive results on all floors ranging from trace to 4% of bulk samples. The southwest comer of the building consistently showed the highest percentage of asbestos. On the floor plans, all positive asbestos samples (including trace amounts) are marked in yellow. Chrysotile was the only mineral identified in the positive results. See appendix B for raw data.

2. Metals — Ambient tested bulk samples for Cadmium, Chromium, Copper, Iron, Lead, Manganese, Nickel, and Zinc. There are no established standards that indicate acceptable heavy metal concentrations in wipe/bulk samples. As a comparison, Superfund site minimum soil clearance limits (NYSDEC TAGM #4046) were used. When compared to the TAGM soil clearance levels, overall metal levels were determined to be high on all floors. The metals found in greatest abundance are iron, zinc, and manganese. Silica, though technically not a metal, was also prevalent in all the samples. See appendix C for raw data.

Though HEPA vacuuming would be effective in removing the dust from non-porous surfaces, this technique cannot sufficiently remove the dust from porous surfaces such as carpets, ceiling tiles and other fabric items, including personal belongings. Further, it is highly probable that computer equipment has also sustained contamination and/or damage from the dust.

3. Mercury - All floor bulk samples showed high Mercury readings. Mercury levels showed a range of 0.06 - 0.88 ppm. Mercury is usually a liquid, but in this case it is in particulate form (as a component of the dust). Most likely it has accumulated as a result of the high volume of fluorescent light bulbs and thermostats that were destroyed. Cleaning with a HEPA-vacuum will remove the Mercury containing particulates from non-porous surfaces. Tests conducted by Emteque report that paper materials emitted no detectable levels of mercury after HEPA vacuuming and cleaning had occurred. See appendix D for raw data.

4. PAils (Polycyclic Aromatic Hydrocarbons) - Using NYSDEC TAGM Superfund soil clearance levels as reference standards for bulks and any levels above detection limits for wipes, Ambient found positive results on all floors. As the PAHs will eventually vaporize, they are not a major concern. See appendix E for raw data.

5. PSG (Poly Chlorinated Biphenyls) — Based on NYSDEC TAGM Superfund soil clearance level standards for bulk samples and any levels above detection limits for wipes, Ambient found positive results for PCBs on all floors except the 6th floor. The PCBs will be cleaned as part of the dust removal. See appendix F for raw data.

NYC-WTC 000124629