1. For oil penetration of up to one inch, combined use of road 

 graders and motorized elevating scrapers is most efficient. 



2. For oil penetration from 1 to 9 inches, use of motorized elevat- 

 ing scraper only is more efficient. 



3. For oil penetration depth of greater than 9 inches, wheeled 

 front-end loaders and bulldozers can be used, wheeled front-end loaders 

 being more effective for firm ground and bulldozers more effective for 

 softer ground. 



In general, fine sand and gravel beaches can be expected to be 

 firm, whereas coarse sand beaches are soft and thus not likely to be 

 able to support wheeled vehicles. The coarser the material and the lighter 

 the oil, the deeper the oil penetration. Amount of oil is a factor in 

 the penetration depth. 



The above apply mostly for heavy oils. For light oils on rocks, 

 most of the contaminant will be evaporated. When light oil soaks into 

 finer material, evaporation can be enhanced by the use of beach cleaning 

 machines or harrow plows. These procedures/equipment are summarized 

 in Table 4. 



The use of detergents increase the penetration of the oil and 

 results in more contamination of the beach than originally existed. 

 The detergents emulsify the oil in water, which makes it more toxic 

 to the biota. 



The quantity of oil spilled and the extent of the beach contami- 

 nation are related factors which affect the procedure selected for beach 

 cleaning. Contamination of beaches from natural oil seeps has been mea- 

 sured at oil concentrations varying from 0.01 to 3 oz/ft^ of beach 

 surface (based on a 500 ft"^ area of measurement) [11 ]• Such a concen- 

 tration of oil represents a severe local contamination, but the materials 

 have been found to disperse in a few days by natural processes. 



In the Torrey Canyon spill, oil concentrations up to 30 oz/ft 

 of sand were observed [1]. Covering the oil with fresh clean sand was 

 found to prevent normal hydraulic drainage of the beach, and ultimately 

 resulted in accelerated beach erosion. 



Sorbent materials provides sorption surface for the oil upon 

 arrival at the beach, but on standing, the oil tends to drain into the 

 sand. Disadvantages of sorbents are the costs and problems involved 

 in gathering and disposing of the material. 



Sand cleaning procedures are not sufficiently advanced to be 

 considered for immediate use in beach cleanup. With further development, 

 these processes may be advantageous for cleaning beach areas. 



Burning of oil on a contaminated beach has not been effective. 

 It is difficult to ignite the oil and to maintain the combustion. Com- 

 plete combustion is not usually achieved and the residue is a heavy 

 black mixture of tar and charcoal. The use of a torch or flame thrower 

 to remove oil from rock outcroppings causes spalling which is hazardous 

 to the operators and disfigures the rock surface. 



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