California brown pelicans fly toward downtown Long Beach, California at sunrise on the eve of Earth Day on April 21, 2007 in Seal Beach, California. At the time of the first Earth Day in 1970, California brown pelicans were well on their way to extinction (David McNew/Getty Images)
The banned pesticide DDT as well as other PCBs have accumulated in large quantities at the bottom of the ocean floor off the coast of Southern California over time. It is estimated that the Palos Verdes Shelf contains about 110 tons of DDT and 10 tons of PCBs, said the EPA's regional Superfund director, Keith Takata.
Fortunately, the site is too deep to directly affect humans. Fish in the area contain elevated levels of DDT and PCBs, which are not safe for consumption. The plan would attempt to reduce DDT and PCB levels in the sediment which would then reduce contamination within fish.
"Signing this interim cleanup plan is a major milestone that puts the Palos Verdes Shelf Superfund Site on the road to remediation," said Takata.
Takata said the EPA plans to cap the area by covering the contaminated area with sediment and continue the outreach program to prevent certain people from eating contaminated fish.
The Montrose Chemical Corp. leaked DDT into the sanitation system, which went directly into the Pacific Ocean, from the early 1950's to 1971. This site was the largest maker of DDT in the world before the ban of the substance. Other industrial sites leaked PCBs into the shelf.
DDT is a pesticide that was commonly used as a deterrent against insects before its ban in 1972. When in contact with humans and other animals, it is known to be very carcinogenic and to cause a plethora of ailments, such as reproductive problems and cancer.
The EPA says that consumption of contaminated fish may increase the risk of getting cancer, and liver and central nervous system damage.
The Palos Verdes Shelf was declared a Superfund cleanup site in 1996 due to the high DDT levels. The EPA estimates that over 1,700 tons of DDT was discharged by Montrose Chemical Corp.
In 2000, a pilot program was initiated by the EPA to place sediment over 1 percent of the affected area to see if there were any potential risks in the area from capping it.
