during the seasons of high waves, whereas other beaches change in height 

 and width during the stormy season. The type of beach involved, therefore, 

 must be ascertained as part of the survey in the early preparation stage 

 of a cleanup operation. 



The porosity of the beach material, for example fine sand vs. coarse 

 sand or gravel, can be a pertinent factor in the depth of oil penetration. 

 A qualitative demonstration of this was found from an experiment conducted 

 previously at NCEL. 



Figure 3 shows a representation of a beach of fine sand that is 

 wetted by water. The capillary action has caused the water to move upward 

 into the sand. A light oil (JP-5) v/as then introduced onto the sand as 

 shown in Figure 4. Note that the penetration occurred only in the dry 

 areas, and that the wetted sand prevented the oil from penetrating the 

 beach area. The preferential wetting of water and the small porosity in 

 fine sand rendered the wet sand to be impervious to oils, especially oils 

 heavier than JP-5. This phenomena has been observed frequently where a 

 heavy oil is deposited on a sand beach. If the beach sand is sufficiently 

 fine, even light oils may not penetrate the beach after it has been 

 saturated with water. 



The higher the porosity of the beach structure, the deeper will be 

 the oil penetration. If the beach surface is open and porous, and 

 if the oil (such as JP-5 and diesel fuels) flows freely, deep penetration 

 of the beach surface can be expected. 



Location and Accessibility . If the beach is remotely located and 

 inaccessible, thorough cleanup of the beach in a short period of time 

 might not be practical. Access to the beach may be restricted by the 

 lack of roads, or roads inadequate for the passage of mechanical removal 

 equipment. Rocks or groins will prevent easy maneuvering of mechanical 

 equipment, or a beach may be too small to permit the use of mechanical 

 equipment. A beach may have such a steep slope that conventional earth- 

 moving equipment become ineffective because the spilling of contaminated 

 sand out of the conveyor [9]. Physical constraints such as these may 

 be the primary factors which will decide the type of equipment to be 

 used for removal of oil. Manual cleanup may be the only practical method 

 in some cases. Note that often building of temporary roads to allow the 

 use of mechanical equipment may be more economical than using manual 

 labor. 



Natural Environment . It is difficult to clean a contaminated beach 

 completely regardless of effort and intention. Natural action of wind, 

 rain, wave, sun, together with chemical and biological degradation 

 fortunately are effective in assisting the oil removal process. Beaches 

 such as those in Santa Barbara have been aided by nature in the final 

 cleanup. 



Self-Renewal Ability. While most beaches are relatively stable, some 

 beaches are constantly being eroded, and others have continual sedimenta- 

 tion. When the latter is the case, replacement of contaminated material 

 that is hauled away will be assisted by natural processes. On the other 

 hand, if the beach is in the process of eroding away by natural seasonal 

 action cleanup effort may be aided. 



