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A variety of techniques were used to address fundamental strategies for addressing the spilled oil, which were: to contain oil on the surface, dispersal, and removal. While most of the oil drilled off Louisiana is a lighter crude, the leaking oil was of a heavier blend which contained asphalt-like substances. According to Ed Overton, who heads a federal chemical hazard assessment team for oil spills, this type of oil emulsifies well. Once it becomes emulsified, it no longer evaporates as quickly as regular oil, does not rinse off as easily, cannot be eaten by microbes as easily, and does not burn as well. "That type of mixture essentially removes all the best oil clean-up weapons", Overton said.〔 On 6 May 2010, BP began documenting the daily response efforts on its web site.〔 On 28 April, the US military joined the cleanup operation.〔 The response increased in scale as the spill volume grew. Initially, BP employed remotely operated underwater vehicles (ROV's), 700 workers, 4 airplanes, and 32 vessels.〔 By 29 April 69 vessels, including skimmers, tugs, barges, and recovery vessels, were in use. By 4 May, the USCG estimated that 170 vessels, and nearly 7,500 personnel were participating, with an additional 2,000 volunteers assisting.〔 On 31 May, BP set up a call line to take cleanup suggestions which received 92,000 responses by late June, 320 of which were categorized as promising.〔 In summer 2010, approximately 47,000 people and 7,000 vessels were involved in the response works. By 3 October 2012, federal response costs amounted $850 million, most of them reimbursed by BP. As of January 2013, 935 response personnel were still involved in response activities in the region. For that time BP's costs for cleanup operations exceeded $14 billion.〔 == Containment == The response included deploying many miles of containment boom, whose purpose is to either corral the oil, or to block it from a marsh, mangrove, shrimp/crab/oyster ranch or other ecologically sensitive areas. Booms extend above and below the water surface and are effective only in relatively calm and slow-moving waters. More than of containment booms were initially deployed to protect the coast and the Mississippi River Delta.〔 By the next day, that nearly doubled to , with an additional staged or being deployed.〔〔 In total, during the crisis one-time use sorbent booms and of containment booms were deployed.〔 Some US lawmakers and local officials claimed that the booms didn't work as intended, saying there is more shoreline to protect than lengths of boom to protect it and that inexperienced operators didn't lay the boom correctly. Billy Nungesser, president of Plaquemines Parish, Louisiana, said the boom "washes up on the shore with the oil, and then we have oil in the marsh, and we have an oily boom. So we have two problems".〔 According to Naomi Klein, writing for the Guardian, "the ocean's winds and currents have made a mockery of the lightweight booms BP has laid out to absorb the oil." Byron Encalade, president of the Louisiana Oysters Association, told BP that the "oil's gonna go over the booms or underneath the bottom", and according to Klein, he was right. Rick Steiner, a marine biologist who closely followed the clean-up operations, estimated that "70% or 80% of the booms are doing absolutely nothing at all".〔 Local officials along the gulf maintained that there was a scarcity of boom, especially the heavier "ocean boom". BP, in its regional plan, says that boom is not effective in waters with waves more than three to four feet high; waves in the gulf often exceed that height.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Deepwater Horizon oil spill response」の詳細全文を読む スポンサード リンク
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