70 
Qualitative field observations suggest that there is a great 
difference in the character of the solids being discharged and in 
particular that these solids have markedly different settling 
properties. Particulate material from the effluent is visible in 
the boil of the Orange County outfall as small black discreet 
particles usually less than 1/l inch in diameter. The particles 
rapidly diminish in number wntil at a distance of about 1,000 feet, 
few are noticeable in the surface waters. Strings or patches of 
grease are rarely seen in this area and when such surface clots do 
occur, they are small and minor in extent. 
From the Hyperion outfall there are on most occasion large 
flat flocculent particles, often an inch or more in diameter in 
the boil and the immediate waters. The particulate material is 
frequently in such great quantities as to reduce the transparency 
to less than 2 feet with the Secchi dise and less than 1% light 
transmission with the transparency meter. The black floccules 
may remain visible in the surface layers for distances exceeding 
two miles, becoming consistently smaller with distance from the 
outfall. Although surface films of grease are not common in the 
waters surrounding the Hyperion outfall, they occur with greater 
frequency than in the Orange County area and may cover several 
hundred square feet of water surface. Such patches have been 
noted as far as ten miles from the outfall. 
Particles in the sewage discharged from the Los Angeles County 
outfall at Whites Point are similar to those seen in the Orange 
County area, except for the frequent occurrence of floatable 
objects. Large floccules are not particularly obvious, nor are 
they visible at great distances from the boil. However, the 
