The British Petroleum
Gulf Oil Spill
is the largest accidental marine
oil spill in the history of
the petroleum industry
It was caused by an explosion on the BP Deepwater Horizon offshore oil platform located 80 kilometers (50 miles) southeast of the Mississippi River delta on April 20, 2010. Most of the 126 workers on the platform were safely evacuated. The Deepwater Horizon sank in about 1,500 meters (5,000 feet) of water on April 22, 2010. The search and rescue operation for 11 missing workers was called off on April 23 by the U.S. Coast Guard. They were all presumed dead.
The sinking of the platform caused crude oil to gush out of the riser – the 1,500 meter (5,000 foot) pipe that connects the well at the ocean floor to the drilling platform on the surface. Attempts to shut down the flow failed when a safety device called a blowout preventer (BOP) could not be activated. After a series of failed efforts to plug the leak, BP announced on July 15 that they had capped the well. The flow of oil into the Gulf of Mexico had lasted for 86 days. It is estimated that about 5 million barrels of oil was released, of which about 800,000 barrels were captured by containment efforts.
(1 barrel = 159 liters (42 gallons). 5 million barrels = 795 million liters (210 million gallons)
Where did the other estimated 4.2 million barrels of oil go?That’s 668 million liters (176 million gallons) of oil disappeared from public view.
The Deep Horizon oil spill was not like other oil spills where the oil had been released on or close to the surface. With the BP spill the oil was released from a pipe 1,500 meters (5,000 feet) below sea level, in open sea. It was impossible to contain. Shifting surface water, caused by changing wind patterns and ocean currents, caused the oil to roll in towards the coastline being carried through the ocean, gradually making its way to the surface. Analysis of satellite imagery by SkyTruth revealed the total oil-slick footprint to be estimated at 176,000 square kilometers (68,000 square miles).
IN situ burn. The cleanup began on April 28 with the first controlled burn of the surface oil, also called in situ burn. Fire booms are used to coral the spill for burning. This works well in shallow waters but not so good in the deep open sea where the oil was rising. An estimated 340 million liters (9 million gallons) of oil was removed from open water via this method
Use of Dispersants In the weeks following the spill, dispersants were applied by BP and various federal agencies. By June 16, 2010, 492 million liters (1.3 million gallons) of dispersant had been deployed—341,500 (902,000) on the surface and 160,123 (423,000) subsea—by far the largest ever use of dispersant on an oil spill.
The use of so much dispersant was ultimately a choice between environments:
- Not using dispersants – the oil would contaminate shoreline habitats and come into contact with birds, marine mammals, or other organisms that exist on the water surface or shoreline.
- Using dispersants – increased the potential exposure of oil to fish and bottom dwelling biota such as clams or oysters.
Oil spill dispersants do not actually reduce the total amount of oil entering the environment. Rather they change the chemical composition of the oil allowing it to to break up into smaller droplets that mix easily with water. The theory was that the smaller droplets would biodegrade quicker. But in reality a large percentage of the oil gradually sunk and mixed with the sediment to form a 8 cmm (3-4 inch) thick toxic layer on the seafloor. To compound the problem, the dispersant mixed into the oil inhibits the bio-degradation by natural oil-consuming bacteria thus prolonging the disaster for decades to come.
The dispersants used in the Deepwater Horizon clean-up were Corexit 9500 and Corexit EC9527A.
Corexit 9500 and Corexit EC9527A have been banned in 18 countries, including the United Kingdom, due to known biological effects on natural systems. It contains a cancerous causing neurotoxin that is acutely toxic to both human and marine life. When oil and corexit are mixed together, the resulting substance becomes 50 times more toxic and penetrates human skin much easier.
Over 30,000 people responded to the spill in the Gulf Coast. They worked to collect oil, clean up the coastline, provide care for oil slicked wildlife and perform any other other tasks required. None of the locals who took part in the clean-up effort were told of the dangers to their health. They were discouraged from wearing protective gear such as respiratory masks, suits, and gloves because it would have more accurately conveyed to the world the true nature of the disaster.
Over 8,000 animals (birds, turtles, mammals) were reported dead just 6 months after the spill, including many that were already on the endangered species list.
A total of 1,700 kilometers (16,000 miles) of coastline has been affected since the oil started to come ashore in June 2010. Three years later, roughly 550 km (340 miles) of coast were still in need of cleanup. Coast Guard cleanup patrols finally drew to a close in April 2014, though crews remain available in the event that more oil related to the spill reaches land.
Part 2 – The Ongoing Environmental and Social Impact (under construction)
During a strong storm, water from the Gulf, mixed with oil and Corexit could make its way into the ecosystem, eventually washing up onto the Gulf’s shores and seeping insidiously into the ground water. Florida’s ground water aqueduct system provides drinking water to 18 million residents.
Part 3 – The Blame Game (under construction)
The legal spin
Part 4 – The Conspiracy (under construction)
Dave Hodges – The Common Sense Show. 10 articles in his Gulf Spill Category list
Encyclopedia of Earth – Deepwater Horizon Oil Spill
Collapse of the Industrial Civilization – Business-As-Usual on a Dying Planet – Excellent article!
Encyclopedia Britannica – Deepwater Horizon oil spill of 2010