53 
data from Orange County, in which the MPN are shown against distance 
and depth, but independent of direction. The tongues cannot represent 
a subsurface flow of sewage away from the outfall for several reasons. 
The most compelling of these is that the temperature and chlorinity 
of the water in the tongues are characteristic of the normal sea 
water in the area rather than being characteristic of the surface 
sewage-sea water mixtures that have similar coliform populations. 
Even if the profiles are greatly distorted because of insufficient 
data, the finding of even individual high subsurface counts in 
areas of normal chlorinity can only be explained by assuming that 
the liquid and solid phases of sewage move differently after being 
discharged into the ocean. The main, if not only, differential 
force acting on the two phases is that of gravity and the high 
subsurface counts are almost certainly due to sedimentation of 
particulate material. 
Although most of the profile results can be explained in this 
fashion, the results obtained on February 12 at Whites Point remains 
a mystery. On this occasion the pattern was confused with alternating 
highs and lows, with the highest count of all being found some 12,000 
feet up coast from the boil at a depth of 65 feet. 
Coliforms in Bottom Sediments 
In the First Quarterly Report, mention was made of the 
detection of coliform bacteria in the sediments over a large area 
surrounding the Hyperion outfall. At that time it was the authors! 
understanding that there had been no large scale introduction of 
coliforms into the area for a period of over a year, and the question 
arose as to whether the organisms found were indeed coliforms and 
