NYC-WTC_000233286

NYC 9/11 Public Portal Document

(b) Waiting Periods. Prior to beginning Phase IIB asbestos abatement work and upon completion of the construction of all regulated abatement work area enclosures and decontamination system enclosures, including establishment of the negative air system, a four hour (4) waiting period with negative air units operating shall be required to insure that all barriers shall remain intact and secured to the walls, ceilings, floors and fixtures.

(c) Waiting Period Exemption. The four (4) hour waiting period may be eliminated for exterior work where negative air is not required.

(d) Inspection of Barriers. All barriers shall be inspected by the asbestos supervisor at least twice daily, before the start of and following the completion of the day’s abatement activities. Inspections are also required on days when there is no Phase II work or support activities scheduled. Inspections and observations shall be documented by the asbestos abatement contractor’s supervisor in a daily project log.

(e) Repairs to Barriers and Enciosures . Damage and defects in the barriers and enclosures shall be repaired immediately upon discovery and shall be documented by the asbestos abatement contractor’s supervisor in a daily project log, prior to resumption of abatement activities.

(f) Testing of Barriers and Enclosures. Smoke tube testing to ensure the effectiveness of all isolation barriers, personal decontamination system enclosures, waste decontamination system enclosures and regulated abatement work area enclosures shall be performed prior to the beginning of abatement activities and at least once a day thereafter until satisfactory clearance air sampling results have been obtained. Negative air pressure ventilation units shall be in operation during this testing. Testing of barriers and enclosures is not required on days when there are no Phase IIB or cleaning activities scheduled. Test results, observations and any modifications shall be documented by the asbestos abatement contractor’s supervisor in a daily project log.

(g) Loss of Enclosure Integrity. If visible emissions or water leaks are observed outside of the regulated abatement work area, or if a glovebag, tent or enclosure of any type fails or loses its integrity, work shall be stopped and the following procedures shall be followed:

(1) Isolation and Critical Barrier Construction. Isolation and critical barriers shall be constructed as follows:

(i) Isolate HVAC Systems. The HVAC systems shall be shut down immediately and all openings shall be sealed with at least six (6) mil fire retardant plastic sheeting and duct tape.

(ii) Isolate Uncontaminated Areas. Passageways to uncontaminated areas of the building or structure shall be sealed with at least six (6) mil fire retardant plastic sheeting and duct tape.

12 NYCRR56 Subparts, Page 72

CITY_21MC100_0 03235092

NYC-WTC_000233358