96 



pore spaces between sand grains in the nearshore region allows 

 water to circulate with little difficulty and as a result, 

 oxidation of organic matter occurs to considerable depths 

 below the surface. The relatively low values of organic 

 carbon in the nearshore region, therefore, are the result of 

 an abundant supply of oxygen and associated bacteria that can 

 penetrate the sediments, together with shifting of sediment 

 by wave and current action. Such conditions facilitate 

 decomposition and transportation of organic debris. 



Organic matter having a density slightly greater than 

 sea water can best accumulate in quiet waters where silt and 

 clay particles are also being deposited. Fine-grained sedi- 

 ment also aids the preservation of organic matter because it 

 is difficult for water to circulate through the small pore 

 spaces of silt and clay particles. 



It is noteworthy that the proposed discharge location is 

 in the general region of nondeposition of sediments so that 

 there probably is considerable motion along the bottom. This 

 may have two important effects on the sewages (1) redistri- 

 bution of the sewage, and (2) faster oxidation of the organic 

 matter. 



The distribution of organic matter in sludge or effluent 

 after it enters sea water at the point of discharge will 

 depend upon: (1) the rate of flocculation or sedimentation, 



(2) the direction and velocity of currents and turbulence, 



(3) rate of decomposition, and (4) slumping and submarine 

 landslides. If the organic matter, largely in the form of 

 sludge but also suspended in the effluent would flocculate 



