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dominant and frequently forms layers of warm water 10 to 30 feet 
thick nearshore in the vicinity of Redondo Beach. 
Gentle upwelling along the Malibu coast causes a mild south- 
easterly directed current which may intersect the northerly flow 
of the man-made current off Venice. This action on occasion 
diverts the northerly flowing sewage field in an offshore direction. 
The diverted flow is mild, not dominant, and does not occur on all 
occasions (Figure 1). 
Frontal storms which enter the southern California area from 
the northwest result in a southeasterly flow of water over the 
entire shelf area. These storm conditions completely eliminate 
the effects of the nearshore wedge of warm water, The changes 
in water motion caused by storm action are infrequent and last 
only 2 to 4 days. Thus, the dominant northerly flow of water in 
a nearshore zone between Redondo Beach and Playa del Rey disappears 
for only short periods of time. 
Because the normal wind and ocean current velocities in Santa 
Monica Bay are generally low throughout the entire year, the sewage 
field from the Hyperion Treatment Plant spreads 2 to 3 miles at 
sea in its northerly flow pattern. However, most of the sewage 
remains in the nearshore zone where water depths are from 50 to 
80 feet. Agitation of the water is normally enough to suspend 
most of the particulate matter for long periods of time so that 
it is carried for distances as great as 5 miles. Therefore, with 
the exception of large dense particles which fall to the sea floor 
within a few thousand feet of the outfall, deposition of particulate 
material is extremely slow. 
