But when the LA Times reported several hotspots discovered as recently as 2020, it was originally surmised that the industrial waste barrels littered among them contained DDT, or a pesticide called Dichlorodiphenyltrichloroethane, that has long since been banned. Dubbed the "halo" barrels because they feature nondescript white sediment halos underwater, scientists finally believe they know what's actually contained within them. According to the U.S. Environmental Protection Agency, the graveyard, named the Southern California ocean disposal site #2, is spread across 14 deep-sea dump sites. These sites are purportedly filled with radioactive waste, refinery waste, chemical waste, oil-drilling waste, and military explosives, which were dumped between the 1930s and 1970s. Very little is known about what these dump sites contain, other than it's likely harmful industrial waste of some kind.