114 Liberty PAH analytical results validation documentation, March 2003

NYC 9/11 Public Portal Document

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' Gilsenan, Michael

From: [email protected] Sent: Wednesday, March 26, 2003 8:42 AM To: Theodorellys, Penny Cc: Radhakrishnan, Krish; Gilsenan, Michael; [email protected] ; [email protected] Subject: Re: FW: Revised PAH results

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R03030157 revised R03030158 revised Report pdf Report, pdf Penny,

Thanks for sending the revised PAH results. The detection limit seems to be the appropriate one, however I would need one additional piece of information from the laboratory to accept the results as valid. The additional information would be a letter (on the laboratory's letterhead) explaining the change in detection limits on the analytical reporting sheets with an attachment of one of the lab sheets/chromatographs that shows the detection limit used during the analysis. I am only requesting this because of the discrepancy highlighted below.

Based on the original PAH results that I received, it appears that the PAH samples were analyzed using a detection limit of 5 ug. The analyses were all conducted on March 10 and 11. The analytical results sheets had a date on top of the page of March 14. The revised PAH results that I received yesterday are identical to the previous results with the exception that the detection limit is now reported as 1 ug and the date at the top of the pages is March 24. The revised results have the same analysis dates and times as the previous samples. Based on the revised results, the only interpretation of this can be that the original analysis was in fact conducted with a detection limit of 1 ug, but erroneously reported as 5 ug, which would make reanalyzing the samples unnecessary (scenario 1). However, I was under the impression that the original detection limit used was 5 ug, and that the only way to get revised results at a detection limit of 1 ug would be to re-run the samples using the lower detection limit. This would result in the date and time analyzed to differ between the original and revised analytical data sheets (scenario 2). Thus, I need confirmation regarding which of the two scenarios above occurred.

Thanks,

Chuck Nace Environmental Toxicologist

USEPA - Region 2 290 Broadway - 18th Floor New York, NY 10007-1866

212.637.3459 212.637.4164 212.637.4360 - fax [email protected]

"Theodorellys, Penny" To: Charles Nace/R2/USEPA/US@EPA

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