EPA review letter, 133-135 Greenwich Street

NYC 9/11 Public Portal Document

submitted prior to the commencement of the Abatement Phase as opposed to the demolition phase.

Corrected as noted.

Notes on Community Air Monitoring Table — Organic Compounds (Dioxin/PCBs/PAHs)

10. Bullet item #1: Airtek may use the two weeks of organic background data collected at 130 Liberty Street for its project as opposed to gathering it for the full week of its background study.

Thank you.

11. Re-write the first sentence of bullet item #2 to state: "Organic samples will be collected at each community monitoring location once a week on a different day of the work week during the Abatement Phase and Demolition Phase, until all days of the work week are used and then the same schedule will be repeated until project completion."

Edited as Noted.

Table 2- Data Reference Levelsfor Community Monitoring

12. The footnote added to Table 2 to the column titled "EPA Site Specific Trigger Levels" and designated as note 2 incorrectly states, "A 4-hour value." Revise Note 2 to state, "A 24-hour value".

Edited as Noted.

13. Note 3: Need to add "for chromium VI" after "USEPA Site Specific Trigger Level" in the last line of note 3. Need to add "(0.6 ug/m3)" after chromium VI in the second to last line of note 3.

Edited as noted.

Table 3 —Abatement Phase Work Area Monitoring

14. Airtek indicates in its response to EPA comment #47 that a reference to blanks has been added to Table 1 which applies to both phases. No such reference has been incorporated into Table 1. Revise the table to include the reference.

Please see reference to blanks in last row of Table 1.

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NYC-WTC 000134346