Chain of custody form for DEP environmental samples, 2001

NYC 9/11 Public Portal Document

Field Observations of Equipment Used Upright vacuums are designed for use on horizontal surfaces such as floors. These use rotating devices to collect dust, and do not provide direct suction force. Brush attachments were used on the horizontal surfaces that could be reached. The hose attachments were limited according to their length and hose type. Plastic hose was not as resilient as rubber or cloth-covered hose. Attachments such as the crevice tools were used with ease because of their small profile. These were made of plastic; therefore, they were not a concern around potential electrical sources. The vacuums were noisy in the areas being cleaned due to the unfurnished state of the units, and accordingly, the enhanced acoustics.

Shop vacuums are designed to provide easy unload of bulk debris. This type of vacuum typically provides a suction head lift of 48-51 inches of water. The shop vacuums were easy to maneuver even when pulled by the hose. They were also noisy in the unfurnished rooms. The hoses and attachments were larger in diameter than those of the upright vacuums. Crevice tools were larger than some spots to be cleaned. Cartridges loaded quickly with the fine dust being suctioned. Use of tube extensions and extra hose lengths facilitated the cleaning of vertical walls and ceilings. The cartridge filters required vacuuming to be cleaned of caked dust. Once this was completed, the suction increased dramatically.

Commercial quality vacuums are designed for heavy use. This type of vacuum typically provides a suction head lift of 82-93 inches of water. Certain accessories were specially designed for specific applications and required some understanding of their operational adjustments. The added instrumentation facilitated monitoring the operation of the equipment. Fine dust clogged the primary filter cloth easily when used in extreme conditions; however, the HEPA filter when checked visually appeared free of dust. Only the cloth filter required vacuuming. The Nilfisk™ vacuum has a duel motor drive, providing an intense suction allowing for better lift of trapped material than that obtained by off-the-shelf equipment. Each Nilfisk™ vacuum arrived with a 20 amp rated plug that did not conform to the receptacles in the building. The appropriate plug ends were procured and installed. At 92.6 pounds, the vacuum can be handled by one person who maneuvers it in a manner similar to the maneuver of a shopping cart. However, two people are required to ascend stairs with the vacuum.

Wet vacuums are designed to clean horizontal porous surfaces with soap and water (shampoo). The wet vacuums used in the study were an upright model, providing a suction head lift of 103 inches of water. This vacuum was easy for one person to use. The vacuum required hot water to work properly. The hot water had to be hand carried to the site in five-gallon buckets because hot water was not available. The vacuum could spray water or soap individually or both soap and water at the same time. It uniformly sprayed soap and water on the carpet. The soap and water was allowed to penetrate the carpet, and was then suctioned off of the carpet. This spraying capability facilitated the removal of dirt, dust, and debris from the surface.

Use of Swiffer* brand cloths was discontinued quickly because of the small coverage area provided. The cloth quickly loaded with dust and dried out. It then streaked the surfaces being cleaned. Both wet and diy types of Swiffer® cloths were used with the same result. Windex® brand cleaner and water was used as a replacement for the Swiffer® cloth.

Use of water without soap on horizontal surfaces resulted in smearing and re-deposit of the dirt. 15

NYC-WTC_000145713