Law Department notice on WTC document preservation, Oct 2001

NYC 9/11 Public Portal Document

Samples will be collected prior to, during and after cleanup in accordance with the SAP to determine the effectiveness of the cleaning. If sample results do not attain cleanup objectives for a specific scenario, the unit will be re-cleaned using the same equipment and re-sampled. If after a second cleaning the results are unsatisfactory the unit will be cleaned using a method proven successful.

6. Disposal ofWaste Generated in Cleanup:

Dust/debris, used protective equipment, clogged vacuum filters, expendables and items discarded by the tenant will be double bagged in 6ml plastic bags and deposited in a roll off container placed out side the building. The roll off container will be transported off site when full and replaced with another roll-off container. Water used for hand washing and equipment washing will be disposed into the sanitary sewer.

4. PROJECT SAMPLING

EPA will perform comprehensive sampling before, during and after the cleanup to evaluate the effectiveness of the work and possible worker exposure. Samples of dust collected by wipe, micro vac, and persoimel pump sampling techniques will be obtained from porous and nonporous surfaces as well as from workers. Prior to the start of work, bulk samples will be collected (if possible) from each unit. If bulk samples cannot be collected, samples will be obtained using wipe or micro - vac techniques. Samples will be collected from the locations, and analyzed for the parameters shown on the tables included as Attachment B. Specific sampling protocols, methods as well as sample management, data validation and reporting are detailed in the SAP.

5. REPORT PREPARATION

Upon completion of the study a summary report will be prepared discussing the work performed under each scenario. The report will present a synopsis of the work, detailing conditions of the units prior to, during and after the cleanup, duration of the cleanup, problems encountered during cleanup and sampling, sample locations, laboratory data summary tables, and QA/QC documentation. This information will be presented to EPA for evaluation and recommendation.

6

NYC-WTC_000145051