5h 
if so, whether they represented survivors of those introduced a 
considerable time ago. As a consequence, their occurrence in the 
Hyperion area was reinvestigated and exploratory work was done in 
the vicinity of the Whites Point and Orange County outfalls. 
Some 70 samples were collected in Santa Monica Bay covering 
essentially the same area previously investigated. The area in 
which positive samples were found in either the present or previous 
survey is outlined in Figure 15. In general, the extent of the 
field appeared about the same on both surveys and the numbers of 
coliforms found in the sediment samples were similar. All typical 
colonies picked from positive confirmed plates proved to be coli- 
forms by the Imvic test and morphological examination. All 
tetrathionate enrichment broths set up for the detection of enteric 
pathogens proved negative. 
The counts made on sediments collected in the vicinity of 
Whites Point and Orange County outfalls have been quite variable. 
Samples from essentially the same location have shown high counts 
on one occasion and low counts on another. In a series of four 
cores taken one after the other near the Whites Point outfall 
making every effort to sample the same location, surface counts 
of nil, 6, 23, and 23/gram wet weight were obtained. This range 
is not excessive and coincides with the range given by three 
separate samples taken from one of the same cores. On the other 
hand, two samples taken near the Orange County boil gave counts 
of nil on one occasion and of 10,000/gram on the other. 
The sampling procedures used for the sediments are now 
believed to be grossly inadequate for the following reasons. 
It can be assumed that the majority of the coliforms occur in a 
