69 
used their procedure in the vicinity of the Orange County outfall. 
Their results were identical with those of the AHF. Since they 
have run many experiments around the Hyperion outfall and we have 
run only one, it is probably that their results give a better 
average picture than ours. 
The question then remains as to whether their disappearance 
time should be used as a basis for predicting the situation around 
the proposed outfall, and the answer to this is probably no. It 
can be taken as established that the disappearance curves around 
the three outfalls differ. The cause of the difference is apparently 
not the differences in volume of sewage being discharged at the 
three outfalls; for if this were the case, one would expect the order 
of disappearance to be Orange County, Whites Point, and Hyperion. 
Nor is it the difference between primary and secondary treatment, 
since then one would expect Whites Point and Orange County effluents 
to give similar results. If it were a question of a difference in 
outfall construction, diffusers as against a single point discharge, 
one would expect the Whites Point area to show the greatest rate 
of disappearance because of the higher initial dilution. The two 
remaining possibilities are that different rates of disappearance 
relate either to differences in the oceanographic conditions in the 
areas, or else to differences in the nature of the material being 
discharged. Although the Whites Point area is quite different 
oceanographically from the other two, there are no known conditions 
that suggest that Orange County and Hyperion should differ appreci- 
ably. On the other hand, field and laboratory data show that the 
effluents from the three outfalls differ markedly. 
