NYC-WTC_000229683

NYC 9/11 Public Portal Document

’Dust Control Evaluation Summary October 11, 2001

et Al. effectiveness after reblading Foams and Detergents Foam that Wets fines and May become Product-specific Surfactants encapsulates penetrates more slippery when wet Significant slip particles effectively than hazard. vrater; contains less than 2% water Soybean oil - Byproduct of Binds soil Forms a solid, Limited soil surface May have odor when Soapstock Soybean Oil particles long-lasting, non­ permeability; should first applied. Slip Distillation together dusting surface; be applied at hazards when in very good soil temperatures of 120 tacky stage surface particle deg F; requires binding properties minimum of 2 days, and longer when temperatures below 65 deg F. for curing through tacky” stage (site would need to be shut down for several days); salt neutralizes product and renders It ineffective Beet Oil Byproduct of Contains See Salts, May be See Salts Vegetable Beets potassium cheaper than byproduct Minimal chloride, salts H&S concerns physical charactenstics similar to salts

Bitumens. Tars, Petroleum, coal Asphalt and Water insoluble Surface crusting, Use of used oils is Resins and plastic resinous wrhendry: fracturing and prohibited; some industry by­ products are provides a degree pothohng may petroleum-based products adhesive, of surface develop: long-term products may binding soil waterproofing, application may contain carcinogenic particles. good residual cause road to PAHs. Slip hazards Petroleum oil effectiveness become too hard for with petroleum oils. products coat reblading; won't soil particles, lower freezing point; increasing petroleum oil mass products lack adhesive charactenstics

Results of comparative studies indicate that for unpaved road sites the most consistently effective suppressant products are the lignin derivatives and salts, specifically calcium and magnesium chlorides. Both of these products are commonly used and are considered to be environmentally safe and economical.

Alternative chemical suppressants are likely to be recommended for dust control of stock piles and debris handling and sorting areas. Surfactants, highly purified bitumen products, and lignin derivatives appear to have qualities that may work well in these areas.

8.0 RECOMMENDATION

Pilot testing is recommended for further evaluation of select technologies. The objective of pilot testing include evaluating the cost-effectiveness of each of the chemical suppressants with respect to the following:

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NYC-WTC_000229686