Deepwater Horizon oil spill

Deepwater Horizon oil spill
The oil slick as seen from space by NASA's Terra satellite on May 24, 2010
Location	Gulf of Mexico near Mississippi River Delta
Coordinates	28.73667°N 88.38716°W / 28.73667; -88.38716
Date	April 20, 2010 – present (5177 days)
Cause
Cause	Wellhead blowout
Casualties	11 dead 17 injured
Operator	Transocean under lease for BP
Spill characteristics
Volume	up to 100,000 barrels (4,200,000 US gallons; 16,000,000 litres) per day
Area	2,500 to 9,100 sq mi (6,500 to 23,600 km2)

The Deepwater Horizon oil spill, also called the BP Oil Spill, the Gulf of Mexico oil spill or the Macondo blowout, is a massive ongoing oil spill in the Gulf of Mexico, now considered the largest offshore spill in U.S. history. The spill stems from a sea floor oil gusher that started with an oil well blowout on April 20, 2010. The blowout caused a catastrophic explosion on the Deepwater Horizon offshore oil drilling platform that was situated about 40 miles (64 km) southeast of the Louisiana coast in the Macondo Prospect oil field. The explosion killed 11 platform workers and injured 17 others; another 98 people survived without serious physical injury.

The gusher originates from a deepwater wellhead 5,000 feet (1,500 m) below the ocean surface. Current estimates of the amount of oil being discharged range from 12,000 to 100,000 barrels (500,000 to 4,200,000 US gallons; 1,900,000 to 15,900,000 litres) per day. The preliminary best estimate that was released on May 27 by the semi-official Flow Rate Technical Group put the volume of oil flowing from the blown-out well at 12,000 to 19,000 barrels (500,000 to 800,000 US gallons; 1,900,000 to 3,000,000 litres) per day, which had amounted to between 440,000 and 700,000 barrels (18,000,000 and 29,000,000 US gallons; 70,000,000 and 111,000,000 litres) as of that date. The exact spill flow rate is uncertain – in part because BP has refused to allow independent scientists to perform accurate measurements – and is a matter of ongoing debate. The resulting oil slick covers a surface area of at least 2,500 square miles (6,500 km²), with the exact size and location of the slick fluctuating from day to day depending on weather conditions. Scientists have also discovered immense underwater plumes of oil not visible from the surface. The Deepwater Horizon spill has surpassed in volume the 1989 Exxon Valdez oil spill as the largest ever to originate in U.S.-controlled waters; it is comparable to the 1,600,000 barrels oil spill caused by Amoco off the coast of Brittany (France) in March 1978 for which Amoco had to pay $120 million, and it is still outranked in the greater Gulf of Mexico by the 1979 Ixtoc I oil spill.

Experts fear that due to factors such as petroleum toxicity and oxygen depletion, the spill will result in an environmental disaster. The spill has damaged the Gulf of Mexico fishing industry, the Gulf Coast tourism industry, and the habitats of hundreds of bird species, fish and other wildlife. Crews are working to block off bays and estuaries, using skimmer ships, anchored barriers, floating containment booms, and sand-filled barricades along shorelines. There are a variety of ongoing efforts to contain the spill and remove outbound oil before more comes ashore along beaches and estuaries of the Gulf of Mexico.

BP (formerly British Petroleum) is the operator and principal developer of the Macondo Prospect, which was thought to hold as much as 50 million barrels (7.9×10^⁶ m³) of oil prior to the blowout (by BP's own estimate). The Deepwater Horizon drilling platform had been leased by BP from its owner, Transocean Ltd. The U.S. Government has named BP as the responsible party in the incident, and officials have said the company will be held accountable for all cleanup costs resulting from the oil spill. BP has publicly accepted responsibility for the oil spill and the cleanup costs, but also has indicated that it was not at fault because the platform was run by Transocean personnel.

The Deepwater Horizon blowout is the third serious incident at a BP-operated site in the United States in the last five years, following the Texas City Refinery explosion in 2005 and the Prudhoe Bay oil spill in 2006. These previous incidents, attributed to lapses in safety and maintenance, have contributed to the damage to BP's reputation and market valuation since the spill.

Background

Deepwater Horizon

Main article: Deepwater Horizon

oil spill

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Location of the Deepwater Horizon on April 20, 2010

The Deepwater Horizon was a floating oil drilling platform — a fifth-generation, ultra-deepwater, dynamically positioned, column-stabilized, semi-submersible Mobile Offshore Drilling Unit (MODU). The platform was 396 feet (121 m) long and 256 feet (78 m) wide and could operate in waters up to 8,000 feet (2,400 m) deep, to a maximum drill depth of 30,000 feet (9,100 m). The $560 million platform was built by Hyundai Heavy Industries in South Korea and completed in 2001. It was owned by Transocean, operated under the Marshalese flag of convenience, and was under lease to BP until September 2013. At the time of the explosion, the Deepwater Horizon was on Mississippi Canyon Block 252, referred to as the Macondo Prospect, in the United States sector of the Gulf of Mexico, about 41 miles (66 km) off the Louisiana coast. In March 2008, the mineral rights to drill for oil on the Macondo Prospect were purchased by BP at the Minerals Management Service's lease sale. The platform commenced drilling in February 2010 at a water depth of approximately 5,000 feet (1,500 m). At the time of the explosion the rig was drilling an exploratory well. The planned well was to be drilled to 18,000 feet (5,500 m) below sea level, and was to be plugged and suspended for subsequent completion as a subsea producer. Production casing was being run and cemented at the time of the accident. Once the cementing was complete, it was due to be tested for integrity and a cement plug set to temporarily abandon the well for later completion as a subsea producer.

Drilling rig explosion

Main article: Deepwater Horizon drilling rig explosion

Anchor handling tugs combat the fire on the Deepwater Horizon while the United States Coast Guard searches for missing crew.

The fire aboard the Deepwater Horizon reportedly started at 9:45 p.m. CDT on April 20, 2010. According to Transocean executive Adrian Rose, abnormal pressure accumulated inside the marine riser and as it came up it "expanded rapidly and ignited". A bubble of methane gas escaped from the well and shot up the drill column, expanding quickly as it burst through several seals and barriers before exploding. Survivors described having less than five minutes to escape as the alarm went off. The explosion was followed by a fire that engulfed the platform. Nine crew members on the platform floor and two engineers died during the explosion. Most of the workers evacuated the rig via diesel-powered fiberglass lifeboats, seventeen others were then evacuated from the workboat by helicopter. Although 94 workers were taken to shore with no major injuries, four were transported to another vessel, and 17 were sent to trauma centers in Mobile, Alabama and Marrero, Louisiana. Initial reports indicated that between 12 to 15 workers were missing. The United States Coast Guard launched a massive rescue operation for the 11 missing persons but called off the search of 23 April after concluding that "reasonable expectations of survival" had passed. After burning for more than a day, Deepwater Horizon sank on April 22, 2010.

Discovery of oil spill

On the afternoon of April 22, 2010, a large oil slick began to spread at the former rig site. Two remotely operated underwater vehicles (ROVs) unsuccessfully attempted to cap the well. BP announced that it was deploying a remotely operated underwater vehicle to the site to assess whether oil was flowing from the well. On April 23, a remotely operated underwater vehicle reportedly found no oil leaking from the sunken rig and no oil flowing from the well. Coast Guard Rear Admiral Mary Landry expressed cautious optimism of zero environmental impact, stating that no oil was emanating from either the wellhead or the broken pipes and that oil spilled from the explosion and sinking was being contained. The following day, April 24, Landry announced that a damaged wellhead was indeed leaking oil into the Gulf and described it as "a very serious spill".

Volume and extent of oil spill

Spill flow rate

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Photo of oil spill live video, May 11 2010

BP initially estimated that the wellhead was leaking 1,000 barrels (42,000 US gallons; 160,000 litres) a day. On April 28, the National Oceanic and Atmospheric Administration estimated that the leak was likely 5,000 barrels (210,000 US gallons; 790,000 litres) a day, five times larger than initially estimated by BP. The estimates of 5,000 barrels (210,000 US gallons; 790,000 litres) a day were based on satellite pictures. According to BP, estimating the flow is very difficult as there is no metering of the flow underwater. Estimates are also complicated by the presence of natural gas in the outflow. The company has refused to allow scientists to perform more accurate, independent measurements of the flow, claiming that it is not relevant to the response and that such efforts might distract from efforts to stem the flow. Former Administrator of the Environmental Protection Agency Carol Browner and Congressman Ed Markey (D-MA) have both accused BP of having a vested financial interest in downplaying the size of the leak.

In their permit to drill the well, BP estimated the worst case flow at 162,000 barrels (6,800,000 US gallons; 25,800,000 litres) per day. In a permit submitted May 13, 2010, BP estimated a worst case spill of 240,000 barrels (10,000,000 US gallons; 38,000,000 litres) per day for each of the two relief wells that are being drilled in an attempt to stop the uncontrolled release. Early estimates of the flow by outside experts were considerably higher than those of BP. Geologist and oil industry consultant John Amos said a more realistic figure was 20,000 barrels (840,000 US gallons; 3,200,000 litres) a day. Oceanographer Ian MacDonald and other sources using satellite imagery put the number as high as 25,000 barrels (1,000,000 US gallons; 4,000,000 litres) a day.

On May 12, BP released a 30 second video of the spill at the site of the broken pipe. Experts contacted by National Public Radio and shown the footage put the leak rate substantially higher than the early estimate. Timothy Crone, an associate research scientist at the Lamont-Doherty Earth Observatory, estimated at least 50,000 barrels (2,100,000 US gallons; 7,900,000 litres) a day was leaking from the well by using another well-accepted method to calculate fluid flows. Eugene Chaing, a professor of astrophysics at the University of California, Berkeley, estimated the leak to be 20,000–100,000 barrels (840,000–4,200,000 US gallons; 3,200,000–15,900,000 litres) a day. Steven Wereley, an associate professor at Purdue University used particle image velocimetry to initially arrive at a rate of 70,000 barrels (2,900,000 US gallons; 11,000,000 litres) per day, with a margin of error of 20 percent. Wereley concluded the leak was likely considerably more than he initially estimated, after viewing the released footage of the leak, stating before Congress that the leak was likely 95,000 barrels (4,000,000 US gallons; 15,100,000 litres) a day. BP, the United States House Select Committee on Energy Independence and Global Warming and United States Senator Bill Nelson are all hosting live streaming video feeds of the spill from 5,000 feet (1,500 m) below sea level, permitting the public and scientists to see the spill volume and estimate the flow independently.

The director of the United States Geological Survey (USGS), Marcia McNutt, is leading the Flow Rate Technical Group — scientists from the U.S. Coast Guard, National Oceanic and Atmospheric Administration, Minerals Management Service, the U.S. Department of Energy and academics outside government who are tasked with providing the government with an independent scientific assessment of the scope of the disaster and of BP's efforts to stop the flow of oil. On May 27, 2010 the government increased its official estimate to 12,000–19,000 barrels (500,000–800,000 US gallons; 1,900,000–3,000,000 litres) a day. The United States Geological Survey views the 12,000–19,000 barrels (500,000–800,000 US gallons; 1,900,000–3,000,000 litres) range as the best initial estimate for the lower and upper boundaries, while other scientists involved in drafting the figure view it as an estimated minimum. According to Ira Leifer, a member of the Flow Rate Technical Group, the group was only provided an approximately seven minute time segment of low-quality video selected by BP, which showed a lot of variability from very low to very high flows.

Spill area

Oil slicks surround the Chandeleur Islands, Louisiana in this aerial photo

The spread of the oil was increased by strong southerly winds caused by an impending cold front. By April 25, the oil spill covered 580 square miles (1,500 km²) and was only 31 miles (50 km) from the ecologically sensitive Chandeleur Islands. An April 30 estimate placed the total spread of the oil at 3,850 square miles (10,000 km²). The spill quickly approached the Delta National Wildlife Refuge and Breton National Wildlife Refuge, where dead animals, including a sea turtle, were found. On May 14, the AP reported that a publicly available model called the Automated Data Inquiry for Oil Spills indicates about 35 percent of a hypothetical 114,000 barrels (4,800,000 US gal) spill of light Louisiana crude oil released in conditions similar to those found in the Gulf now would evaporate, that between 50 and 60 percent of the oil would remain in or on the water, and the rest would be dispersed in the ocean. In the same report, Ed Overton says he thinks most of the oil is floating within 1 foot (30 cm) of the surface. The New York Times is tracking the size of the spill over time using data from the National Oceanic and Atmospheric Administration, the US Coast Guard and Skytruth. By June 4, 2010, the oil spill had fouled 125 miles of Louisiana’s coast, had washed up along Mississippi and Alabama barrier islands, and was found for the first time on a Florida barrier island, at Pensacola Beach, with part of the Gulf Islands National Seashore.

Underwater oil plumes

University of California Berkeley engineering professor Robert Bea argued there was "an equal amount that could be subsurface", subsurface oil being "near impossible to track". On May 13, tarballs began washing up on the shores of three Louisiana parishes and were possibly originating from the oil leak. On May 15, researchers from the University of Southern Mississippi, aboard the research vessel RV Pelican, identified oil plumes in the deep waters of the Gulf of Mexico, including one as large as 10 miles (16 km) long, 3 miles (4.8 km) wide and 300 feet (91 m) thick in spots. The shallowest oil plume the group detected was at about 2,300 feet (700 m), while the deepest was near the seafloor at about 4,200 feet (1,300 m). Other researchers from the University of Georgia have found that the oil may occupy multiple layers. The undetermined amount of hydrocarbons in these underwater plumes may explain why satellite images of the ocean surface have calculated a flow rate of only 5,000 barrels (210,000 US gal) a day, whereas studies of video of the gushing oil well have variously calculated that it could be flowing at a rate of 25,000–80,000 barrels (1,000,000–3,400,000 US gal) a day. On May 27, marine scientists discovered a second oil plume, stretching 22 miles (35 km) from the leaking wellhead toward Mobile Bay, Alabama. The oil has dissolved into the water and is no longer visible, and researchers say they are worried these undersea plumes may be the result of the use of chemical dispersants to break up the oil.

Marine biologist Rick Steiner said that the likelihood of extensive undersea plumes of oil droplets should have been anticipated from the moment the spill began, given that such an effect from deepwater blowouts had been predicted in the scientific literature for more than a decade and had been confirmed in a test off the coast of Norway. He criticized the National Oceanic and Atmospheric Administration for not setting up an extensive sampling program to map and characterize the plumes in the first days of the spill. BP has challenged the validity of the multiple reports from scientists that vast plumes of oil from the spill were spreading underwater, stating its sampling showed no evidence that oil was massing and spreading in the gulf water column.

Expansion predictions

Some unspecified scientists predict that the Gulf Stream could pick up the oil and carry it around Florida to the East Coast, but on May 5, Robert Weisberg of The University of South Florida said winds would take the oil away from the Loop Current, which becomes the Gulf Stream. Ruoying He of North Carolina State University, head of the Ocean Observing and Monitoring Group, said if the oil reached the Gulf Stream, then south Florida, including the Keys, would likely be affected. Whether it comes ashore farther north depends on local winds, but the Gulf Stream moves away from the coast southeast of Charleston, South Carolina, at a formation called the Charleston Bump. According to Susan Lozier of Duke University, in late spring the winds would blow away from the shore of the Carolinas. Rich Luettich, director of the University of North Carolina Institute of Marine Sciences in Morehead City, said the oil could remain a problem for as much as a year, or even longer. He did say in the unlikely event the oil reached North Carolina's coast, the Outer Banks would provide significant protection.

On May 19, scientists monitoring the spill with the European Space Agency Envisat radar satellite stated that oil reached the Loop Current, which flows clockwise around the Gulf of Mexico towards Florida, and may reach Florida within 6 days. The scientists warn that because the Loop Current is a very intense, deep ocean current, its turbulent waters will accelerate the mixing of the oil and water in the coming days. "This might remove the oil film on the surface and prevent us from tracking it with satellites, but the pollution is likely to affect the coral reef marine ecosystem". National Oceanic and Atmospheric Administration acknowledged, on May 19, that "a small portion of the oil slick has reached the Loop Current in the form of light to very light sheens."

On May 29, President Obama called the inability to stop the flow "as enraging as it is heartbreaking." Larry Crowder, marine biologist at Duke University, predicted the spill could reach 100 million gallons before a permanent solution is found, and with that much oil, damage to the Florida coast and the East Coast appeared more likely. James H. Cowan, a biological oceanographer at Louisiana State University, said a hurricane could result in oil reaching farther inland, even affecting rice and sugar cane crops. A hurricane could also delay actions that would lead to a permanent solution, and it could spread the oil further or deeper in the ocean.

On June 3, a computer model showed that oil would likely reach the Loop Current and travel to East Coast beaches by July. Changes in weather as well as the Loop Current itself could affect the outcome, but the maximum possible speed would be 100 miles per day. The main stream would likely stay 50 to 60 miles offshore, but "pockets of oil" could reach the coast, according to Thom Berry of the South Carolina Department of Health and Environmental Control. Because of the distance, experts said, only a few tar balls would be likely to reach the Carolinas; significant environmental damage appeared very unlikely because oil "would be heavily diluted".

Independent monitoring of contamination

Wildlife and environmental groups accused BP of holding back information about the extent and impact of the growing slick, and urged the White House to order a more direct federal government role in the spill response. In prepared testimony for a congressional committee, National Wildlife Federation President Larry Schweiger said BP had failed to disclose results from its tests of chemical dispersants used on the spill, and that BP had tried to withhold video showing the true magnitude of the leak.

On May 19, 2010, BP established a live feed of the oil spill to meet the requests of the Chairman of the House Select Committee on Energy Independence and Global Warming, Edward J. Markey. This decision was made after hearings in Congress accused the company of withholding data from the ocean floor and of blocking efforts by independent scientists to come up with estimates for the amount of crude flowing into the Gulf each day.

On May 20, 2010 United States Secretary of the Interior Ken Salazar indicated that the U.S. government will verify how much oil has leaked into the Gulf of Mexico. On the same day, the heads of the Environmental Protection Agency and the United States Department of Homeland Security told BP chief executive Tony Hayward in a letter that the company had "fallen short" of its promises to keep the public and the federal government informed about the spill, writing that "BP must make publicly available any data and other information related to the Deepwater Horizon oil spill that you have collected." Environmental Protection Agency Administrator Lisa P. Jackson and United States Secretary of Homeland Security Janet Napolitano asked for the results of tests looking for traces of oil and dispersant chemicals in the waters of the gulf. BP did not respond to requests for comment about the letter, the Washington Post reported in a story titled, "Estimated rate of oil spill no longer holds up."

The media has complained that the Coast Guard and BP have prevented them from viewing affected areas. On May 18, 2010, CBS reporter Kelly Cobiella tried to visit the beaches in the Gulf of Mexico to report on the disaster. She was met by BP contractors and American Coast Guard officers who threatened her with arrest if she did not leave. The Coast Guard officials specified that they were acting under the authority of BP. On May 25, a scheduled flyover was denied permission after BP officials learned that a member of the press would be on board.

Attempts to stop the oil leak

The rig's blowout preventer, a fail-safe device fitted at source of the well, did not automatically cut off the oil flow as intended when the explosion occurred. BP attempted to use remotely operated underwater vehicles to close the blowout preventer valves on the well head 5,000 feet (1,500 m) below sea level, a valve-closing procedure taking 24–36 hours. BP engineers predicted it would take six attempts to close the valves. As of May 2, 2010, they had sent six remotely operated underwater vehicles to close the blowout preventer valves, but all attempts were ultimately unsuccessful.

Oil was known to be leaking into the gulf from three different locations. On May 5, BP announced that the smallest of three known leaks had been capped. This did not reduce the amount of oil flowing out, but it did allow the repair group to focus their efforts on the two remaining leaks.

Short-term efforts

BP engineers have attempted a number of techniques to control or stop the oil spill. The first and fastest was to place a 125-tonne (276,000 lb) container dome over the largest of the well leaks and pipe the oil to a storage vessel on the surface. This option was untested at such depths. BP deployed the system on May 7–8 but it failed when gas leaking from the pipe combined with cold water to form methane hydrate crystals that blocked up the steel canopy at the top of the dome. The excess buoyancy of the crystals clogged the opening at the top of the dome where the riser was to be connected.

Following the failure, on May 11 a smaller containment dome, dubbed a "top hat", was lowered to the seabed. Like the first containment dome, the dome has been deployed successfully in the past but not at such a depth. The "top hat" dome originally was planned as BP's next attempt to control the spill and there has been no explanation for why BP engineers decided to try the insertion tube first.

On May 14, engineers began the process of positioning a 4-inch wide riser insertion tube tool into the 21-inch-wide burst pipe. After three days, BP reported the tube was working. Collection rates varied daily between 1,000 and 5,000 barrels (42,000 and 210,000 US gallons; 160,000 and 790,000 litres), the average being 2,000 barrels (84,000 US gallons; 320,000 litres) a day, as of May 21. The collected gas rate ranged between 4 and 17 million cubic feet per day (110×10^³ and 480×10^³ m³/d). The gas was flared and oil stored on the board of drillship Discoverer Enterprise. 924,000 US gallons (22,000 barrels) of oil was collected before removal of the tube so shutdown efforts could begin.

BP next tried to shut down the well completely using a technique called "top kill". The process involves pumping heavy drilling fluids through two 3-inch (7.6 cm) lines into the blowout preventer that sits on top of the wellhead. This would first restrict the flow of oil from the well, which then could be sealed permanently with cement. The top kill procedure, approved by the Coast Guard on May 25, commenced on May 26 and, according to BP sources, while failure could be evident in minutes or hours it might take "a day or two" before its success could be determined. On May 27, U.S. Coast Guard Adm. Thad Allen, who is coordinating the government response, indicated that engineers had succeeded in stopping the flow of oil and gas into the Gulf of Mexico. He further stated that the well still had low pressure, but cement would be used to cap the well permanently as soon as the pressure hit zero. However, BP officials said it was not possible to tell how far down the well the mud may have reached and declined to speculate on the odds of actually stopping the flow. "We have some indications of partial bridging which is good news. I think it's probably 48 hours before we have a conclusive view." On May 29, BP announced that the attempt to clog the ruptured oil well with "junk" had failed.

After three consecutive failed attempts at the top kill, on May 29 BP moved on to their next contingency option, the Lower Marine Riser Package (LMRP) Cap Containment System. The operational plan first involves cutting and then removing the damaged riser from the top of the failed Blow-Out Preventer (BOP) to leave a cleanly-cut pipe at the top of the BOP’s LMRP. The cap is designed to be connected to a riser from the Discoverer Enterprise drillship and placed over the LMRP with the intention of capturing most of the oil and gas flowing from the well. During the cutting of the pipe, the diamond blade saw became stuck and was later freed, but BP had to use shears instead and the cut is "ragged", meaning the cap would be harder to fit. On June 3, the cap was attatched, and on June 4, BP claimed the cap collected 76,000 gallons its first day; Thad Allen of the Coast Guard estimated the daily amount at 42,000 gallons, but this represented less than 10 percent of leaking oil. On June 6, BP CEO Tony Hayward said the containment cap was capturing 10,000 barrels (420,000 US gallons) of oil per day which he estimated to be "the majority, probably the vast majority of the oil."

Long-term efforts

BP is drilling relief wells into the original well to enable them to block it. Once the relief wells reach the original borehole, the operator will pump drilling mud into the original well to stop the flow of oil. Transocean's Development Driller III started drilling a first relief well on May 2 and was at 12,090 feet as of May 29. Development Driller II also started drilling a second relief on May 16 and was at 8,576 feet as of May 29. This operation will take two to three months to stop the flow of oil (BP also confirmed in late May that they did not expect the relief well to operate before August) and will cost about US$100 million per well.

Use of explosive devices

On May 24, 2010 BP said it ruled out conventional explosives, saying that if the company tried blasts to crimp the well and failed, “We would have denied ourselves all other options.” Federal officials also confirmed neither Energy Secretary Steven Chu nor anyone else ever considered using a nuclear device under the gulf because of not only environmental but also political risks (doing so would violate Comprehensive Nuclear-Test-Ban Treaty, which United States signed).

Containment and cleanup

United States Environmental Services' workers prepare oil containment booms for deployment.

BP, which was leading the cleanup, initially employed remotely operated underwater vehicles, 700 workers, four airplanes and 32 vessels to contain the oil. After the discovery that the undersea wellhead was leaking, the oil cleanup was hampered by high waves on April 24 and 25. According to Hayward, BP will compensate all those affected by the oil spill saying that "We are taking full responsibility for the spill and we will clean it up and where people can present legitimate claims for damages we will honor them. We are going to be very, very aggressive in all of that." On May 6, BP launched a section on their corporate web site devoted to the daily response efforts.

On April 28, the US military announced it was joining the cleanup operation. Doug Suttles, chief operating officer of BP, welcomed the assistance of the US military. The same day, the US Coast Guard announced plans to corral and burn off up to 1,000 barrels (42,000 US gallons; 160,000 litres) of oil on the surface each day. It tested how much environmental damage a small, controlled burn of 100 barrels (4,200 US gallons; 16,000 litres) did to surrounding wetlands, but could not proceed with an open seas burn due to poor conditions. By April 29, 69 vessels including skimmers, tugs, barges and recovery vessels were active in cleanup activities. On April 30, President Barack Obama announced that he had dispatched the Secretaries of the Department of Interior and Homeland Security, as well as the Administrator of the Environmental Protection Agency and the National Oceanic and Atmospheric Administration to the Gulf Coast to assess the disaster.

Clouds of smoke billow up from controlled burns taking place in the Gulf of Mexico.

In an attempt to minimize impact to sensitive areas in the Mississippi River Delta area more than 100,000 feet (30 km) of containment booms were deployed along the coast. By the next day, this nearly doubled to 180,000 feet (55 km) of deployed booms, with an additional 300,000 feet (91 km) staged or being deployed. On May 2, high winds and rough waves rendered oil-catching booms largely ineffective.

As of April 30, approximately 2,000 people and 79 vessels were involved in the response and BP claimed that more than 6,300,000 US gallons (150,000 barrels) of oil-water mix had been recovered. On May 4, the U.S Coast Guard estimated that 170 vessels, and nearly 7,500 personnel were involved in the cleanup efforts, with an additional 2,000 volunteers assisting. On May 26, all of the commercial fishing boats helping in the clean up and recovery process were ordered ashore. A total of 125 commercial vessels which had been outfitted with equipment for oil recovery operations were recalled after some workers began experiencing health problems.

The type of oil involved is also a major problem. While most of the oil drilled off of Louisiana is a lighter crude, because the leak is deep under the ocean surface the leaking oil is a heavier blend which contains asphalt-like substances, and, according to Ed Overton, who heads a federal chemical hazard assessment team for oil spills, this type of oil emulsifies well, making a "major sticky mess". Once it becomes that kind of mix, 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 and others said.

On May 21, 2010, Plaquemines Parish president Billy Nungesser publicly complained about the federal government's hindrance of local mitigation efforts. State and local officials had proposed building sand berms off the coast to catch the oil before it reached the wetlands, but the emergency permit request had not been answered for over two weeks. The following day Nungesser complained that the plan had been vetoed, while Army Corps of Engineers officials claimed that the request was still under review. Gulf Coast Government officials have released water via the Mississippi River diversions in effort to create an outflow of water that would keep the oil off the coast. The water from these diversions comes from the entire Mississippi watershed. Even with this approach, the National Oceanic and Atmospheric Administration is predicting a "massive" landfall to the west of the Mississippi River at Port Fourchon.

On May 23, 2010, Louisiana Attorney General Buddy Caldwell wrote a letter to Lieutenant General Robert L. Van Antwerp of the US Army Corps of Engineers, stating that Louisiana has the right to dredge sand to build barrier islands to keep the oil spill from its wetlands without the Corps' approval, as the 10th Amendment to the U.S. Constitution prevents the federal government from denying a state the right to act in an emergency. He also wrote that if the Corps "persists in its illegal and ill-advised efforts" to prevent the state from building the barriers that he would advise Louisiana Governor Bobby Jindal to proceed with the plans and challenge the Corps in court.

On June 3, BP said barrier projects ordered by the Coast Guard's Thad Allen would cost $360 million.

On June 4, Ecosphere Technologies - a diversified water engineering and environmental services company - deployed a non-chemical water treatment system to assist in the remediation efforts.

Dispersants

On May 1, two United States Department of Defense C-130 Hercules aircraft were employed to spray oil dispersant. Corexit EC9500A and Corexit EC9527A are the main oil dispersants being used. These contain propylene glycol, 2-butoxyethanol and a proprietary organic sulfonic acid salt. On May 7, Secretary Alan Levine of the Louisiana Department of Health and Hospitals, Louisiana Department of Environmental Quality Secretary Peggy Hatch, and Louisiana Department of Wildlife and Fisheries Secretary Robert Barham sent a letter to BP outlining their concerns related to potential dispersant impact on Louisiana's wildlife and fisheries, environment, aquatic life, and public health. Officials are also requesting BP release information on the effects of the dispersants they are using to combat the oil spill in the Gulf of Mexico.

A C-130 Hercules drops an oil-dispersing chemical into the Gulf of Mexico.

The Environmental Protection Agency approved the injection of dispersants directly at the leak site, to break up the oil before it reaches the surface, after three underwater tests. Corexit EC9500A and EC9527A are neither the least toxic, nor the most effective, among the dispersants approved by the Environmental Protection Agency, and they are banned from use on oil spills in the United Kingdom. Twelve other products received better toxicity and effectiveness ratings, but BP says it chose to use Corexit because it was available the week of the rig explosion. Critics contend that the major oil companies stockpile Corexit because of their close business relationship with Nalco. By 20 May, BP had applied 600,000 US gallons (2,300,000 L) of Corexit on the surface and 55,000 US gallons (210,000 L) underwater.

Independent scientists have suggested that the underwater injection of Corexit into the leak might be responsible for the plumes of oil discovered below the surface. However, National Oceanic and Atmospheric Administration administrator Jane Lubchenco said that there was no information supporting this conclusion, and indicated further testing would be needed to ascertain the cause of the undersea oil clouds.

On May 19, the Environmental Protection Agency gave BP 24 hours to choose less toxic alternatives to Corexit. The alternative(s) had to be selected from the list of Environmental Protection Agency-approved dispersants on the National Contingency Plan Product Schedule with application beginning within 72 hours of Environmental Protection Agency approval of their choices, or provide a "detailed description of the alternative dispersants investigated, and the reason they believe those products did not meet the required standards." On May 20, US Polychemical Corporation reportedly received an order from BP for Dispersit SPC 1000, a dispersant it manufactures. US Polychemical stated it was able to produce 20,000 US gallons (76,000 L) a day in the first few days and increasing up to 60,000 US gallons (230,000 L) a day thereafter. BP spokesman Scott Dean said Friday, May 20, that BP had responded to the Environmental Protection Agency directive with a letter "that outlines our findings that none of the alternative products on the Environmental Protection Agency 's National Contingency Plan Product Schedule list meets all three criteria specified in yesterday's directive for availability, toxicity and effectiveness." BP has so far refused to offer an acceptable "detailed description of the alternatives investigated and the reason they believe those products did not meet the required standards" on a public Web site, as called for in a letter sent on May 20 by Department of Homeland Security Secretary Janet Napolitano and Environmental Protection Agency Administrator Lisa P. Jackson to BP CEO Tony Hayward, claiming such full disclosure would compromise its confidential business information. In a press conference on May 24, EPA administrator Lisa P. Jackson said the 700,000 US gallons (2,600,000 L) of dispersants already used was "approaching a world record" and that “dissatisfied with BP’s response” she was ordering the EPA to conduct their own evaluation of alternatives to Corexit, while ordering BP to take “immediate steps to scale back the use of dispersants.”

Consequences

Ecological effects

Heavily oiled Brown Pelicans captured at Grand Isle, Louisiana on June 3, 2010 wait to be cleaned of Gulf spill crude at The Fort Jackson Wildlife Care Center in Buras, LA.

More than 400 species live in the islands and marshlands at risk, including the endangered Kemp's Ridley turtle. In the national refuges most at risk, about 34,000 birds have been counted, including gulls, pelicans, roseate spoonbills, egrets, terns, and blue herons. As of May 30, dead animals collected from the spill zone included 491 dead birds, 227 sea turtles, and 27 mammals including dolphins, although according to the U.S. Fish and Wildlife Service these animals have not been determined to have been killed by the oil. Samantha Joye of the University of Georgia indicated that the oil could harm fish directly, and microbes used to consume the oil would also add to the reduction of oxygen in the water, with effects being felt higher up the food chain. According to Joye, it could take the ecosystem years and possibly decades to recover from such an infusion of oil and gas. On Tuesday May 18, 2010, BP chief executive Tony Hayward insisted the environmental impact of the oil spill in the Gulf of Mexico will be "very, very modest".

It is possible the Gulf Stream sea currents may spread the oil into the Atlantic Ocean. If oil follows the Loop Current to the east coast of the United States, it could impact wildlife even without the oil reaching the beaches. Duke University marine biologist Larry Crowder said threatened loggerhead turtles on Carolina beaches could swim out into contaminated waters. Sea birds, mammals, and dolphins could also be affected. Ninety percent of North Carolina's commercially valuable sea life spawn off the coast and could be contaminated if oil reaches the area. Douglas Rader, a scientist for the Environmental Defense Fund, said prey could be negatively affected as well. Steve Ross of UNC-Wilmington said coral reefs off the East Coast could be smothered by too much oil. Damage to the ocean floor is as yet unknown, and marine life between the ocean floor and the surface could be affected.

Impact on fisheries

The closed fishing area encompassed 88,522 square miles (229,270 km²), about 37% of the Gulf of Mexico Federal Waters, as of June 2, 2010

On April 29, 2010, Louisiana Governor Bobby Jindal declared a state of emergency in the state after weather forecasts predicted the oil slick would reach the Louisiana coast. An emergency shrimping season was opened on April 29, 2010, so that a catch could be brought in before the oil advanced too far.By April 30, the Coast Guard received reports that oil had begun washing up to wildlife refuges and seafood grounds on the Louisiana Gulf Coast. On May 19, heavy oil from the spill began to make landfall along fragile Louisiana marshlands. By May 20 oil had reached populated areas of the Louisiana coast. On May 22, The Louisiana Seafood Promotion and Marketing Board stated said 60 to 70 percent of oyster and blue crab harvesting areas and 70 to 80 percent of fin-fisheries remained open. The Louisiana Department of Health and Hospitals closed an additional ten oyster beds on May 23, just south of Lafayette, Louisiana, citing confirmed reports of oil along the state's western coast.

On May 2, 2010 the National Oceanic and Atmospheric Administration closed commercial and recreational fishing in affected federal waters between the mouth of the Mississippi River and Pensacola Bay. The closure initially incorporated 6,814 square miles (17,650 km²). By June 2, 2010, NOAA increased the area thirteen times in a month to encompass 88,522 square miles (229,270 km²), or about 37 percent of the Federal waters in the Gulf of Mexico.

On May 24, the federal government declared a fisheries disaster for the states of Alabama, Mississippi and Louisiana.

Sick workers

By early June, dozens of people, mostly oil spill workers, had filed complaints with the Louisiana Department of Health and Hospitals regarding oil exposure. Eleven people had been treated and released from one New Orleans hospital alone, complaining of respiratory problems, headaches and nausea.

Financial impacts

On June 1, 2010, BP reported that its own expenditures on the oil spill had reached $990 million, a figure that excludes claims from fishermen and other affected industries. An April 30 Merrill Lynch report found that five companies connected to the disaster, BP, Transocean, Anadarko Petroleum, Halliburton and Cameron International, had lost a total of $21 billion in market capitalization since the explosion. Currently, the United States Oil Pollution Act of 1990 limits BP's liability for non-cleanup costs to $75 million unless gross negligence is proven. BP has said it would pay for all cleanup and remediation regardless of the statutory liability cap. Nevertheless, some Democratic lawmakers are seeking to pass legislation that would increase the liability limit to $10 billion. Analysts for Swiss Re have estimated that the total insured losses from the accident could reach $3.5 billion. According to UBS, final losses could be $12 billion. According to Willis Group Holdings, total losses could amount to $30 billion, of which estimated total claims to the market from the disaster, including control of well, re-drilling, third-party liability and seepage and pollution costs, could exceed $1.2 billion.

As of June 1, 2010,BP's stock has lost more than one-third of its value compare to the period before accident, equivalent to $62.7 billion in market capitalization. BP is reportedly vulnerable to a corporate takeover as a result of the fall of its stock value and potential for continuing decline. As a result of the accident, insurance of offshore property and marine liability risks had hardened. The future changes in the US legislation on control of well and liability policy limits will likely result with higher levels of insurance for offshore oil exploration and production.

Initial cost estimates to the fishing industry were $2.5 billion, while the impact on tourism along Florida's Paradise Coast could be $3 billion. Some local officials in Louisiana have expressed concern that the offshore drilling moratorium imposed in response to the spill will further harm the economies of coastal communities. The oil industry employs about 58,000 Louisiana residents and has created another 260,000 oil-related jobs, accounting for about 17 percent of all Louisiana jobs. The oil spill has not raised the price of crude oil, which declined during the Deepwater Horizon crisis. In the United States, where Memorial Day weekend signals the beginning of the annual summer driving season, gas prices have dropped instead of going up.

Effect on tourism

Although many people cancelled their vacations at first, hotels close to the coasts of Louisiana, Mississippi and Alabama reported dramatic increases in business from 2009 during the first half of May 2010. On May 25, BP gave Florida $25 million to promote its beaches, which the oil had not reached, and the company planned $15 million each for Alabama, Louisiana and Mississippi. The Bay Area Tourist Development Council bought digital billboards showing recent photos from the beaches as far north as Nashville, Tennessee and Atlanta. Along with these and other assurances that the beaches are so far unaffected, hotels have cut rates and offered deals such as free golf. Also, cancellation policies have changed, and refunds have been promised to those where oil arrives. However, 2009 was a slow year, and those working to deal with the spill have rented rooms in the area. Revenues remain below 2009 levels due to the special deals.

By June, many people were cancelling vacations while they could do so, fearing the arrival of oil on the beaches. University of Central Florida economist Abraham Pizam said the oil slick may become "the worst disaster in the history of Florida tourism."

Litigation

On April 22, the families of two missing workers filed lawsuits in federal and state court in Louisiana against BP and Transocean, alleging negligence and failure to meet federal regulations. Since then, more than 130 lawsuits relating to the spill have been filed. According to Michael Stag, a lawyer for the Louisiana Environmental Action Network, the cases are likely to be combined into one court, as a multidistrict litigation, for evidence gathering and pretrial decisions. BP, Transocean, Cameron International, and Halliburton Energy Services have all been named in one or more of the lawsuits. Because the spill has been largely lingering offshore, the plaintiffs who can claim damages so far are mostly out-of-work fishermen and tourist resorts that are receiving cancellations. The oil company says 23,000 individual claims have already been filed, of which 9,000 have so far been settled. BP and Transocean want the cases to be heard in Houston, seen as friendly to the oil business. Some plaintiffs want the case heard in Louisiana, while others prefer Mississippi or Florida. Five New Orleans judges have recused themselves from hearing oil spill cases because of stock ownership in companies involved or other conflicts of interest. BP has retained a major law firm, Kirkland & Ellis, to defend most of the lawsuits arising from the oil spill.

Public relations

Some statements and actions by BP have generated a great deal of public and congressional anger. Initially BP downplayed the incident; CEO Tony Hayward called the amount of oil and dispersant "relatively tiny" in comparison with the "very big ocean." Hayward also stated that the environmental impact of the Gulf spill would likely be "very very modest." . Later, he said that the spill was a disruption to Gulf Coast residents and himself adding, “You know, I’d like my life back.” He later apologized for his statements. The company has required oil spill cleanup workers, including many fishermen, to sign non-disclosure agreements and not publicly talk about the spill. BP contractors and Coast Guard officials threatened to arrest CBS reporters investigating an oily beach in South Pass, Louisiana, citing “BP’s rules.” Representative Ed Markey, chairman of a House energy committee investigating the oil spill, suggested that the oil company has misled the public about the magnitude of the spill, and advised people to not trust what the company is saying.

On May 30 BP hired Anne Kolton, former head of public affairs at the U.S. Department of Energy and former spokesperson for Dick Cheney as head of U.S. media relations. Furthermore, BP established a new division, headed by board member and managing director Bob Dudley, an American citizen and former CEO of TNK-BP, to handle the company's response.

On June 4 BP began running TV ads featuring CEO Tony Hayward as he apologized for the disaster, also adding, "We've helped organize the largest environmental response in this country's history." The company also ran print ads in newspapers including The New York Times, the Wall Street Journal, USA Today and The Washington Post. The cost for this PR campaign was about $50 million, according to Jon Bond, co-founder of the Kirshenbaum Bond Senecal agency. The TV ads, which appeared on national cable and broadcast networks, had the same tag line as the newspaper ads: "We will get this done. We will make this right." President Obama responded to this development later that day on his third trip to the Gulf region, saying, "My understanding is that BP has contracted for $50 million worth of TV advertising to manage their image during the course of this disaster... what I don't want to hear is when they're spending that kind of money on TV advertising, that they're nickel-and-diming fishermen or small businesses here in the Gulf who are having a hard time."

Public reaction

Within several weeks after the spill began, the amount of public anger and protests against BP for its role in the oil spill had risen considerably in the US and worldwide. By June 5, a Facebook page called “Boycott BP” had obtained 384,000 fans and generated media stories.The Public Citizen consumer advocacy group has had more than 15,500 people sign an online petition pledging not to buy any BP products for three months. Across the US, thousands of people participated in dozens of protests at BP gas stations and other locations. While BP does not own any gas stations in the US, it does sell gasoline to BP, ARCO and other gas stations in the US and internationally. In London, where BP is headquartered, in late May, Greenpeace activists scaled the St. James Square company offices and unfurled mock BP logo banners imprinted with oil stains reading "British Polluters".

Public opinion

President Obama being briefed on the spill by Assistant for Energy and Climate Change Carol Browner on Air Force One en route to Louisiana in early May 2010

Regarding the handling of the situation, 53 percent of Americans rate President Obama's performance as poor or very poor while 43 percent consider it good or very good, according to a USA Today/Gallup poll taken on May 24–25. Some 60 percent said the federal government has done a poor or very poor job while 35 percent rate it good or very good. A CBS News poll conducted May 20–24 also found a negative evaluation of Obama, with 45 percent disapproving compared to 35 percent who approved, and 20 percent undecided.

BP had worse polling numbers, with 73 percent in the Gallup poll describing its response as poor or very poor, while 24 percent say it has been good or very good. In the CBS survey, 70 percent disapproved of BP's response compared to 18 percent who approved, with 12 percent undecided.

U.S. and Canadian offshore drilling policy

Main article: United States offshore drilling debate

Secretary of the Interior Ken Salazar stated that the disaster would have huge ramifications for energy development in the oceans all around the world. Salazar ordered immediate inspections of all deep-water operations in the Gulf of Mexico. An Outer Continental Shelf safety review board within the Department of the Interior will provide recommendations for conducting drilling activities in the Gulf. The United States President issued an order so that the federal government will not be issuing new offshore drilling leases until a thorough review determines whether more safety systems are needed.

On April 28, the National Energy Board of Canada, which regulates offshore drilling in the Canadian Arctic and along the British Columbia Coast, issued a letter to oil companies asking them to explain their argument against safety rules which require same-season relief wells. Five days later, the Canadian Minister of the Environment Jim Prentice said the government would not approve a decision to relax safety or environment regulations for large energy projects. On May 3, Governor of California Arnold Schwarzenegger withdrew his support for a proposed plan to allow expanded offshore drilling projects in California.

According to the U.S. Energy Information Administration (EIA), offshore drilling, just in the Gulf of Mexico, accounts for 23.5% of U.S. oil production. The chief argument in the U.S. offshore drilling debate has been to make the United States less dependent on imported oil. American dependence on imports grew from 24% in 1970 to 66% in 2008. Former U.S. President George W. Bush identified dependence on imported oil as an urgent "national security concern".

Investigations

On April 22, 2010, the United States Coast Guard and the Minerals Management Service launched an investigation of the possible causes of the explosion. On May 11, 2010, the Obama administration requested the National Academy of Engineering conduct an independent technical investigation to determine the root causes of the disaster so that corrective steps could be taken to address the mechanical failures underlying the accident. The United States House Committee on Energy and Commerce asked Halliburton to brief it as well as provide any documents it might have related to its work on the Macondo well.

Attention has focused on the cementing procedure and the blowout preventer, which failed to fully engage. A number of significant problems have been identified with the blowout preventer: There was a leak in the hydraulic system that provides power to the shear rams. The underwater control panel had been disconnected from the bore ram, and instead connected to a test hydraulic ram. The blowout preventer schematic drawings, provided by Transocean to BP, do not correspond to the structure that is on the ocean bottom. The shear rams are not designed to function on the joints where the drill pipes are screwed together or on tools that are passed through the blowout preventer during well construction. The explosion may have severed the communication line between the rig and the sub-surface blowout preventer control unit such that the blowout preventer would have never received the instruction to engage. Before the backup dead man's switch could engage, communications, power and hydraulic lines must all be severed, but it is possible hydraulic lines were intact after the explosion. Of the two control pods for the deadman switch, the one that has been inspected so far had a dead battery.

Just hours before the explosion, a BP representative overruled Transocean employees and insisted on displacing protective drilling mud with seawater. One of the BP representatives on the board responsible for making the final decision, Robert Kaluza, refused to testify on the Fifth Amendment grounds that he might incriminate himself; Donald Vidrine, another BP representative, cited medical reasons for his inability to testify, as did James Mansfield, Transocean's assistant marine engineer on board.

On June 1, 2010 U.S. Attorney General Eric Holder announced that he has opened a criminal investigation of the BP oil spill. "There are a wide range of possible violations, and we will closely examine the actions of those involved in this spill," Holder said.

National Commission on the BP Deepwater Horizon Oil Spill

On May 22, 2010 President Obama announced that he has signed an executive order establishing the bipartisan National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, with former Florida Governor and Senator Bob Graham and former Environmental Protection Agency Administrator William K. Reilly serving as co-chairs. The purpose of the commission is to "consider the root causes of the disaster and offer options on safety and environmental precautions."

Atlantis Oil Field safety practices

Main article: Atlantis Oil Field

The Deepwater Horizon disaster has given new impetus to a number of Congressional Representatives to pressure the Minerals Management Service to investigate safety practices on BP's Atlantis PQ offshore platform in the Atlantis Oil Field. A whistleblower report to the Minerals Management Service in March 2009 stated that "over 85 percent of the Atlantis Project's Piping and Instrument drawings lacked final engineer-approval," as legally required. Furthermore, the report suggested "the project be immediately shut down until those documents could be accounted for and independently verified." BP and other oil industry groups wrote letters objecting to a proposed Minerals Management Service rule last year that would have required stricter safety measures. The Minerals Management Service changed rules in April 2008 to exempt certain projects in the central Gulf region, allowing BP to operate in the Macondo Prospect without filing a blowout plan.

See also

• Timeline of the Deepwater Horizon oil spill
• List of oil spills
• Exxon Valdez oil spill (1989)
• Ixtoc I oil spill (1979) – the largest oil spill in the Gulf of Mexico
• Offshore oil and gas in the US Gulf of Mexico
• Oil Pollution Act of 1990

External links

• Live Video link Live Feeds from remotely operated vehicles (BP website)
• Deepwater Horizon Response from the Deepwater Horizon Unified Command (U.S. Government/BP/Transocean)
• Deepwater BP Oil Spill at Whitehouse.gov
• Deepwater Horizon Incident, Gulf of Mexico from the National Oceanic and Atmospheric Administration (NOAA)
• Deepwater Horizon Joint Investigation by the U.S. Coast Guard and Mineral Management Service
• Gulf of Mexico response from BP, including live video feed of riser
• Reporting of Oil Spill-Related Illnesses and Injuries to DHH - Louisiana Department of Health and Hospitals

Directories

• Deepwater Horizon oil spill at Curlie
• Oil Spill in the Gulf of Mexico online resources from The Gulf of Mexico Sea Grant Programs
• Deepwater Horizon Oil Spill links to government documents and resources from the University of South Alabama
• Gulf of Mexico Oil Spill at Google Crisis Response

News media

• Full coverage on BBC News
• Full coverage on C-SPAN video library
• Full coverage on CNN
• Full coverage on The Guardian
• Full coverage from the Houston Chronicle
• Full coverage from the Los Angeles Times Greenspace
• Full coverage from The Miami Herald
• Full coverage on The New York Times
• Full coverage from The Times-Picayune (New Orleans)
• Full coverage from the Press-Register (Mobile, Alabama)
• Full coverage from The Wall Street Journal

Blogs

• GulfBlog at UGA Department of Marine Sciences by Prof. Samantha Joye
• Anger Mounts in Gulf Coast over BP Oil Spill video report by Democracy Now!

Images

• Rig fire at Deepwater Horizon 4/21/10 video at CNN iReport
• GOES-13 satellite images on the CIMSS Satellite Blog
• Visualizing the Deepwater Horizon Oil Spill Disaster on beowulfe.com