22 



butions aroiand these two outfalls from the simple pattern of 

 surface dispersion that exists at the Orange County outfall. 

 The character of the effluent,, the oceanographic conditions, 

 and the depth of water at Whites Point also contribute to 

 form a still different pattern than at the other two outfalls. 

 The patchy distribution or pockets of high concentration 

 of nutrients noted at considerable distances from the outfalls 

 is explained by variations in the effluent as well as inade- 

 quate mixing on discharge. Phosphate determinations on the 

 effluent before discharge were made at Orange CouBty on 

 December 19 and 20, by Mr. William Henderson, County Sani- 

 tation District of Orange County. On December 19, the phos° 

 phate determination showed a fairly even distributiori in parts 

 per thousand over the eight hour period that determinations 

 were made. The range on this day was from 3,2 o/oo to 4.8 o/oo. 

 On the other hand, the phosphate in the effluent on December 

 20 ranged from o/oo to 16.0 o/oo throughout the same period 

 of time. Although the analyst has stated that some trouble 

 was experienced with the method of determination and the data 

 are not necessarily to be considered completely reliable, the 

 observations do indicate that not only a wide diurnal range, 

 but a large hourly range does occur in the phosphate content 

 of the effluent. The increase in phosphate on December 20 in 

 the effluent also aids in explaining the great increase in 

 phosphate observed at sea on this day, and the erratic distri- 

 bution of the maximum concentrations. 



