EPA work plan review, 133-135 and 21-23 buildings, August 2005

NYC 9/11 Public Portal Document

Mr Rajappan Radhakrishnan — NYC DEP 133-135 Greenwich Street Variance Request Airtek Project 05-0701— August 11, 2005

Exterior: We are requesting a variance from the following subsections to facilitate the decontamination of the facade: Section 1-81(j) No pre-cleaning of the work area(s) Section 1-81(m) Partial plasticization of the work area(s) Section 1-82(a) & 1-83(a) Remote decontamination facilities Section 1-91 No negative air Section 1-112(d) & 1-112(e) No l & 2nd settling period and no 2nd & 3rd cleaning The exterior of the building was decontaminated as a part of the NYC DEP Building Exterior Cleaning Program following 9/11/01. Airtek's visual inspection of the facade indicates that it is advisable to conduct low-pressure power washing prior to initialing demolition activities. The exterior of the building will be cleaned in accordance with the NYC DEP WTC Dust/Residue Roof & Facade Cleaning Procedures. Interior: Phase 1— Soft Strip: We are requesting a variance from the following subsections: Section 1-125(i) Isolation Barriers We request relief from 1-125(i): Isolation Barriers. It is the intent of the project to seal all windows and communicating openings to the outside of the building from the outside with two layers of 6-mil poly and plywood barriers. The intent of this action is to create a sealed structure that will allow decontamination activities within the building while reducing the possibility of migration of dust to the outside of the structure. All interior materials, including moveable objects, will be subject to decontamination and removal or, if porous, will be bagged and disposed of as ACM waste. All ceiling systems (plaster, tiles, sheetrock, etc.), wall systems (plaster, wall board, etc.), and floor systems, (tiles, carpet, etc.) will be removed and bagged for disposal as ACM waste. Remaining structural members, pipes, boiler, freezer boxes and roof mounted HVAC units will be wet-wiped, HEPA vacuumed, and encapsulated with a penetrating encapsulant. All accessible interstitial spaces will be wet-wiped, HEPA-vacuumed, and encapsulated. Operable windows will be articulated, wet wiped, HEPA-vacuumed, and encapsulated. Full worker and waste decontamination facilities will be attached to the entrance on Thames Street. The decontamination facilities will comply with NYC DEP Title 15 §1- 82 & §1-83. Phase II- In Place Exterior ACM: We are requesting a variance from the following subsections for the roofing materials:

Section 1-41(c) During abatement air sampling inside the work area---__~ Section 1-41(d) No post abatement clearance air monitoring Section 1-102(b) Not to fully saturate ACRM with amended water

ENVIRONMENTAL CONSULTANTS

NYC-WTC-000134902