DEP memo on 114 Liberty Street clearance data validity, Aug

NYC 9/11 Public Portal Document

City of New York that require the determination of the presence and quantity of ACM prior to alteration, renovation, modification, or demolition activities.

It should also be noted that several errors were detected in the calculation of sample concentrations. Two samples had incorrect concentrations report^, samples 221160-02 and 221160-03 (reported on page 6 of the report) should have reported concentrations of 1,471,401 and 432,765 s/cm^, respectively.

Mold and Bacteria Data

Based upon the results that were received, one wipe sample was collected for mold and bacteria from a kitchen floor on the third floor of the building. The sample was analyzed by P&K Microbiology Services, Inc. with the number and type of fungi and bacteria being counted and identified. Seven fungi species were identified with the highest count for any one species being 900 colony forming units/square inch (CFU/in^) and a total sum of 2,200 CFU/in^, while six bacteria species were identified with the highest count for any one species being 500 CFU/in^ and a total sum of 1,600 CFU/in^.

Mold

Although there are no specific standards, a general rule of thumb for interpreting mold data considers concentrations less than 10,000 CFU/in^ to be low and typical of background levels. The concentrations for each individual species, as well as the total sum for all species was w'ell below 10,000 CFU/in^ and should be considered background levels. In addition, the dominant fungi uitii wcie observed are commonly identified species and are ubiquitous in the environment, both indoors and outdoors.

Bacteria

As with mold, there are no standards for comparison However, one report (htlp://\\'\\w.atsdr.cdc.gov/HAC/PHA/franklinfungi/ief pkhtml) from the Agency for Toxic Substances and Disease Registry (ATSDR) states that concentrations of Bacillus at 1,000 CFU/in^ and Staphylococcus at 2,400 CFU/in^ are low’ and most likely are a normal part of the bacterial load. The concentrations reported from 114 Liberty are much lower than these values and should be considered background levels. In addition, the dominant species found was Staphylococcus, a common human associated bacterium.

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