Information on foam testing:
The Tragic State of the Gulf of Mexico: Sampling Reveals Oil and Dispersants on Mississippi Coast, Dahr Jamail and Erika Blumenfeld for Truthout, January 12, 2011:
A dead jellyfish found on Long Beach, Mississippi, nearby a large amount of the aforementioned thick, brown foam, was tested and found to contain 15 ppm of ethanol, one of the chemicals in the dispersants, along with low levels of n-Butanol, another chemical present in the dispersants…
Based on comparative analysis of Corexit 9500 and the sample collected, the sample appears to contain approximately 500 ppm of dispersant.
A water sample in the same area, taken in an area covered in thick, brown foam, contained propylene glycol, one of the confirmed ingredients of Corexit 9500.
A water sample at this area also contained ethelene glycol, as did a water sample taken from a fish pond in the front yard of a resident's home in Ocean Springs.
Another water sample from the beach contained diethylene glycol BE.