According to the U.S. Geological Survey, between 1946 and 1970 "more than 47,800 drums and other containers of low-level radioactive waste were dumped onto the ocean floor west of San Francisco." Only thirty miles from the Golden Gate Bridge it is both the first and largest offshore nuclear waste dump in the U.S. When the radioactive waste barrels floated to the surface of the water, the soldiers shot holes in them to help them sink.
The entire radioactive disposal project around Farallon was overseen by the Atomic Energy Commission, and was not slowed until the Environmental Protection Agency stepped up in the mid 1960s.
Barrels aren't the only radioactive materials that were dumped at the site. The USS Independence, part of the Bikini Atoll nuclear tests (see Runnit Island) stationed half a mile from one of the blasts to test the effects was also left to rot, practically on the shores of San Francisco. Once it had been sufficiently annihilated by nuclear blasts, its irradiated smoking wreckage was towed to Farallon to be sunk. Soldiers also reported regularly transporting the carcasses of animals killed in radiation experiments for disposal at the site.
As of this date there has never been a large-scale study of the effects of the areas nuclear contamination, although allegedly most of the material had decayed by 1980. The area is now protected as the Gulf of the Farallones National Marine Sanctuary and is the home to great white sharks, seals, and whales.