Q&A and FAQ regarding WTC response, Oct 2001

NYC 9/11 Public Portal Document MflY-29-2002 21:24 U.S. epazdepp 212 6373772 P.05-^08

8. (EPA’s air testing violates the AHERA protocols)

Issue - EPA is violating the AHERA regulations by using the clearance lest (70 f/mrn2) without performing specific abatement procedures in advance of applying the 70 f/mm2 standard. Additionally, it is argued that the AHERA clearence test is intended to catch gross contamination problems only.

Response - EPA never intended to strictly adhere to the extensive AHERA regulations governing school asbestos abatement at V/TC. As discussed in the previous response, the AHERA standard was utilized as a general indicator of “background” (see previous response) asbestos contamination. While the standard is not specifically applicable to measurements of outdoor air concentrations of asbestos, it was nonetheless considered a reasonable benchmark of asbestos contamination. In effect, the “indoor” clearance test for re-entry into schools was employed to inform evaluation of asbestos sampling data in ambient air around the WTC.

9. (EPA use of 1% asbestos level for cleanups will result in Ineffective cleanups)

Issue - EPA and NYCDEP arc claiming that only dusts over 1% or more are hazardous.

Response - EPA has stated that if a substance contains 1% or more asbestos it is considered to be an asbestos containing material. This is consistent with regulatory definitons in the National Emission Standards for Hazardous Air Pollutants (NESHAPS) and AHERA. Based upon this definition, NYCDEP has required certain remediation actions on the part of property owners. The hazard posed by asbestos contaminated bulk dust/debris is a function not only of concentration but of total mass of material, re-intrainment potential and the presence of exposed populations. EPA has taken the position that it is prudent to consider WTC related dust as potentially asbestos contaminated. For example, shortly after the disaster, EPA mobilized HEPA vacuum trucks to clean all dust/debris littered streets in the impacted area of Lower Manhattan rather than selectively cleaning streets where results from bulk sampling indicated greater than 1% asbestos.

Issue - In reference to the Libby, Montana mining site, EPA has stated that soils containing less than 1% asbestos are capable of producing airborne concentrations greater than .01 free. It has been further asserted that this concentration (i.e., .01 free) is over the action level for declaring a public health emergency.

Response - The relationship between asbestos concentration in settled material and ambient air is highly variable and is influenced not only b'- -sbestos concentration but also by the total mass of asbestos contaminated material and its .c-entrainment potential. Additionally, the determination of a public health emergency is based on the tenets of risk assessment which would consider numerous factors including: fiber dimension as well as concentration, exposure pathways/duration, and actual/potential populations exposed. As a result of the WTC disaster and the subsequent clean-up action, an upper bound exposure duration from WTC-rclated contaminants was estimated to be 1 year. Based on a 1 year exposure duration, the AHERA

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