Law Department notice on WTC document preservation, Oct 2001

NYC 9/11 Public Portal Document

Study and Non-Study

Basement Areas Elevator Shaft and Motor Room, Trash Compactor Room, Fire Equipment Room.

Cleaning Method: Test 4A - Surface cleaning using industrial HEP A filtered vacuums. Air filtration using an air filtration device (AFD). Equipment Used: Nilfisk™ Vacuum (CFM 127) Filtration status: HEPA Common Area Size: 642 sq. ft.; 5,136 cu. ft. (Total of all areas, elevator shaft not included.) AFD Status: Required AFD specification when required: 400/600 cfm Unit air exchange rate: 12.8 min @ 400 cfm Minimum Air Exchange Required: Every 30 minutes

Description: Basement areas include: A trash compactor room, an equipment room containing the building fire protection controls to the ceiling sprinkler system, a motor control room for the elevator, and access to the elevator shaft containing the elevator compartment, as well as a common room which provided access to all the above areas. These basement areas are accessed through an outside stairwell located in the Cedar Street sidewalk.

The floors are constructed of concrete. The walls are composed of painted concrete block or brick. The elevator shaft floor is compacted soil. The shaft walls are composed of mortar and brick. Floor joists and decking of the first floor constitute the ceiling of the basement areas. All basement areas appeared to have been hose washed. No significant dust was present. With the exception of the ceiling materials, no porous materials were present. Debris such as cardboard boxes, used hydraulic oil, rags, discarded elevator parts, and dead rodents were disposed of prior to cleanup. The elevator shaft was inspected from the fifth floor to the below grade location when access was provided by the elevator contractor. The vertical wall surfaces of the shaft were constructed of brick and mortar and presented no visible dust down to the second floor. The lower section in the elevator shaft contained sand accumulation from natural deterioration. The exposed brick under the elevator framework, to a height of approximately six feet from the bottom of the shaft, was encrusted with mud, indicating a high water line some time during the building history.

Difficult Areas Encountered: None

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NYC-WTC_000145195