63 
over short periods of time. It can be assumed that once the 
suspended matter reaches the surf zone no further sedimentation 
will occur. Consequently, coliforms brought into the surf would 
then disappear only by dilution of slow die-off. With an upcoast 
drift, material brought into the beach less than 6,000 feet away 
from the outfall could be transported greater distances away. How 
rapidly coliforms would disappear would then depend on dilution and 
whether a diminution from this factor or others occurs is not known. 
It would appear that an investigation of the fate of coliforms in 
the surf zone is a necessary step in understanding the situation 
at Orange County. 
Finally, it may be that the coliform counts on the beach are 
not directly related to the sewage being discharged, but instead 
are determined by the distribution of coliforms in the bottom 
sediments. It is conceivable, from the scattered data obtained, 
that the bottom has a high coliform content for a large area 
surrounding the outfall. If this field of coliforms extends in- 
shore for a sufficient distance, it is possible that any oceano- 
graphic condition that stirs up the bottom will result in a fresh 
introduction of coliforms into the water along the beach. One 
would expect from this hypothesis that a correlation should exist 
between beach comts and local wave action. More complete infor- 
mation is required on the extent of the bottom coliform field before 
this possibility can be properly evaluated. 
In summary, although the beach count data do not correlate 
exactly with the predictions from the dye patch experiments, the 
discrepancies can be explained without discarding the observed 
rate of disappearance as being typical for the average conditions 
around the outfall. 
