NYC-WTC_000233286

NYC 9/11 Public Portal Document

(i) Where the asbestos project regulated abatement work area extends outward 25 feet and extends downward one floor to encompass a passage or vehicular door which must be used for either a primary entrance or by an emergency vehicle thereby precluding sealing such door, a tunnel structure (with sides and roof) built of plywood sheeting, covered with at least two (2) layers of at least six (6) mil plastic, shall extend outward 25 feet horizontally from the line of vertical projection of the roof edge downward to grade level (2) Preliminary Preparation. Regulated abatement work area preparation shall also comply with sections 56-7.2, 7.3, 7.4, 7.5, 7.6, 7.7 and 7.9. (3) Decontamination System Location. The personal and waste decontamination system enclosures can be remote but must be within 50’ of the building/structure entrance used by the asbestos handlers(workers), and shall be removed only after obtaining satisfactory clearance air results for the regulated abatement work area or an acceptable visual inspection has determined that the abatement is complete, as per Section 56-9. 2(d). (4) Critical Barriers. Prior to the placement of critical barriers, affected surfaces shall be pre-cleaned using HEPA-filtered vacuum equipment and wet cleaning methods. All openings within the regulated abatement work area shall be sealed with critical barriers installed as per Section 56- 7.11(a), prior to beginning Phase II B activity on the project. The critical barriers shall be removed only after satisfactory clearance air sampling results have been obtained or the asbestos project is complete. The requirements of Section 56-7.11(b-e) do not apply. Additional requirements are as follows: Roofs: (i) All openings (including operable windows, doors, ducts, grilles, communicating openings, etc.) one (1) story above and one (1) story below the roof level of the regulated abatement work area (this includes any building/structure within twenty-five (25) feet of the immediate work area), shall be sealed directly with two (2) layers of at least six (6) mil flame-retardant plastic sheeting. All vent openings which cannot be sealed shall be extended vertically a minimum of eight (8) feet and remain in operation. (ii) A polyethylene drape or curtain may be used instead of plasticizing the windows individually. The drape may be removed after the asbestos project is complete. (iii) The drape or curtain, if used, shall be made of two (2) layers of a continuous eighteen (18) foot curtain (drape) of at least six (6) mil plastic hung from the top of the wall or parapet. The plastic curtain shall be secured using nailer strips and ram set charges or other methods approved by the Project Supervisor. The bottom of the

12 NYCRR56 Subpart 11, Page 104

CITY_21MC100_0 03235124

NYC-WTC_000233390