EPA review letter, 133-135 Greenwich Street

NYC 9/11 Public Portal Document

Part 1: Work Plan — Decontamination/Deconstruction 133-135 Greenwich Street and 21-23 Thames Street Airtek Project 05-0701— Rev 3 September 16, 2005

Lead 25 ug/m3 Manganese 100 ug/m3 ,cLà' :po?<\ CC Mercury Nickel 12.5 ug/m3 50 ug/m3 ~~ Zinc 1,000 ug/m3

5 inside work area (IWA) samples will be collected iAn each floor. 5 outside work are (OWA) for ACM will be collected from areas outside each floor (roof, exterior, previously cleared floors, tc.) of the subject buildings. In addition, 5 IWA samples for metals will be collected Ijm each floor. All samples will be collected using aggressive sampling techniques. Upon completion of clearance sampling on the top floor, the floor will be sealed off, and sampling of the next floor down will commence. Details on sampling methodologies are included in the ECAMP document (submittal Part II). Qeçoo1. 7.0 Abatement Phase ,~Q, es

7.1 Part I - Exterior 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 initializing demolition activities. The exterior of the building will be cleaned in accordance with the NYC DEP WTC Dust/Residue Roof & Facade Cleaning Procedures included in Attachment I.

Building facade clean-up via low pressure washing: d OAp ~kt i n 2

1. At grade level, a-work place/restricted areas 1 be established. This area shall be plasticized with one (1),lIyer of 6-mil plastic from one (1) foot up the building exterpIwall to the edge of the sidewalk. At the edge of the sidewalk, wood shall be placed under the plastic to create a large catch basin for the water run-off. It shall be cordoned off with clearly identifiable asbestos hazard tape.

2. A low pressure washing technique, moving from top to bottom, / O. C C€S shall be employed to minimize water bounce-back. The facade shall be washed with a low pressure wash not to exceed 250 psi. bo Om 1 3. The collected water run-off shall be pumped to 55-gallon drums. Aliquots from each drum of wash water will be collected. For each day of work, the aliquots will be composited into one sample to be analyzed for Full TCLP and RCRA characteristics. If the water is not regulated under RCRA, it will be filtered through a 5 micron filter prior to disposal to the NYC sewer system per NYC Title 15, Part 1-82 (b) 1. If testing indicates the water is regulated under RCRA, it will be handled, package, stored and disposed in strict accordance with its categorization.

NYC-WTC 000134183