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of a half knot velocity or more occur periodically, the sewage 
field could be carried 15,000 feet in six hours and thus bring 
excessive coliforms into the beach areas as observede This 
supposition could be checked if there were some pattern from which 
times of excess counts could be predicted. Unfortunately, no such 
basis exists, and it would probably be necessary to make many trips 
of the type already carried out until one, by coincidence, happened 
to coincide with a day of excessive beach counts. 
An alternate possibility of the unusual conditions hypothesis 
is that the character of the sewage effluent alters in sedimentation 
characteristics from time to time so that the extra disappearance 
of coliforms over and above dilution is retarded or eliminated. 
It is obvious that the longer the suspended solids remain on the 
surface, the farther the sewage field can extend. The authors do 
not have sufficient knowledge of the characteristics and variations 
in the Orange County sewage to know whether this alternative has 
any validity. 
A third possibility is that the high beach counts are 
correlated with periods of excess plankton in the inshore waters. 
There is some evidence in the literature that coliforms may be 
associated, mechanically or otherwise, with plankton and thus be 
more widely distributed as the plankton are transported through 
the water. At the moment, there is little relation evident between 
the available plankton data and the beach counts. 
Fourthly, it is possible that the coliforms, once reaching the 
surf zone, are carried upcoast by a longshore drift. This idea is 
based on the supposition that sedimentation is a major factor in 
the disappearance of coliforms and that die-off is a minor one 
