EPA review letter, 133-135 Greenwich Street

NYC 9/11 Public Portal Document

Mr Rajappan Radhakrishnan - NYC DEP 21-23 Thames Street Variance Request Airtek Project 05-0701- Revised September 29,2005

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 1't & 2nd settling period and no 2nd & 3 cleaning The exterior of the building was decontaminated as a part of the NY Ilding Exterior Cleaning Program following 9/11/01. Airtek's visual inspection of fa de d roof indicates that it is advisable to conduct low-pressure power washing prior t initialing d molition activities. The exterior of the building will be cleaned in accordance with th NYC DEP C Dust/Residue Roof & Façade Cleaning Procedures. Interior: Phase I —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 at a minimum. Additional waste characterization will be conducted per Part IV Waste Management Plan. 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 at a minimum. Remaining structural members, pipes, boiler and freezer boxes 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 Interior Friable ACM: Upon completion of the soft strip phase, interior friable ACM will be abated. 1. Pipe Insulation — 57 If The pipe insulation will be abated utilizing NYC DEP Tent and Glovebag procedures. Phase III - 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 1-81(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

NYC-WTC 000134157