Gulf of Mexico Oil Spill

On 22 April 2010, fires from an explosion two days earlier sank the Deepwater Horizon oil rig located in the Gulf of Mexico about 84 kilometers (52 miles) southeast of the coastal city and port of Venice, Louisiana. The deadly oil-well blowout created a massive oil spill from a deep-water well located 1500 meters (5,000 feet) below the surface that ultimately became the worst accidental marine oil spill in history. The spill continued for 87 days, closing a significant portion of the Gulf to fishing, fouled approximately 600 miles of coastline, and washed oil into marshes, wetlands, and inland waterways. The spill delivered a crippling blow to the economic base of the region, disrupting lives and livelihoods along the central and northern Gulf Coast. The spill and cleanup efforts killed thousands of birds and marine animals, imperiling both local and migratory species.

Estimates of the volume of oil gushing into the Gulf during 87 days of leakage increased steadily as scientists gained access to high-resolution video of the leaking well and other data. The oil leak was initially estimated by BP (formerly British Petroleum) at 1,000 barrels of oil (about 42,000 gallons) per day. For several weeks, both BP and U.S. government officials clung to a spill estimate of 5,000 barrels (210,000 gallons) of oil per day. However, based on continued satellite observations and other measurements, an increasing array of experts immediately and consistently asserted that the rate of oil leakage was significantly greater. By June, continued observation of the gushing flow of oil escaping from an overwhelmed BP containment cap system caused officials to further raise estimates of the rate of oil leakage to a range of 35,000 barrels (1.47 million gallons) to 60,000 barrels (2.52 million gallons) of oil per day. In August 2010, scientists and engineers working for the U.S. government estimated that just prior to initially capping the well on 15 July, 2010, the rate of leakage was 53,000 barrels (2.27 million gallons) of oil per day. Because the August estimate is based upon direct pressure readings taken from inside the capped well, scientists described the estimate as the most accurate to date. Prior estimates depended upon indirect estimates derived from video monitoring and spill simulation models.

Although in the high range of prior spill estimates, the study confirmed expectations that the amount of oil gushing into the Gulf gradually declined over the 87 day period it took to initially cap the well. Scientists now estimate that when reservoir pressures were at their highest levels during the early weeks of the spill, about 62,000 barrels (2.6 million gallons) of oil leaked from the damaged well infrastructure each day. Even with an error rate estimated at plus or minus 10 percent, the new official estimates confirmed that the BP spill—estimated to total approximately 5 million barrels (210 million gallons) of oil—surpassed the estimated 3.3 million barrels (approximately 140 million gallons) of oil released during the 1979 Ixtoc I spill to become the worst accidental marine oil spill in history. The Ixtoc 1 spill followed a Petroleos Mexicanos' (PEMEX) rig explosion in the Bay of Campeche (the southern Gulf of Mexico off Mexico's coast). The 2010 BP spill far surpassed the 11 million gallons of oil spilled into Alaskan waters following the 1989 grounding of the tanker Exxon Valdez.

U.S. President Barack Obama described the BP spill as the worst environmental disaster in U.S. History. Oil invading wetland areas coated and killed marine mammals, fish, and birds. Subsurface oil began to pollute and poison oyster beds and shrimp nurseries. Environmental experts asserted that destruction of wetlands, marshes, and estuary areas will significantly alter and degrade the food chain for coastal and marine ecosystems. Plumes of subsurface oil created or contributed to the formation of large oxygen depleted dead zones stretching from the ocean floor to the ocean surface.

The Deepwater Horizon, under lease to BP, was owned and operated by Transocean, a Swiss-based company. The rig was designed to operate in waters up to 8,000 feet deep. The rig was not yet in full production, but was carrying out exploratory offshore drilling. Eleven of the 126 crewmembers aboard the rig at the time of the blast were missing, and are presumed dead. Although an investigation is ongoing, including a review by a special Presidential Commission, experts initially assumed that a gas bubble or bubbles caused the explosion. Gas bubbles can work their way up a drill hole because of unusual geologic features or because of failures in safety equipment. If a gas bubble passes through the riser connecting the blowout preventer stack (BOP) and shut-off valves on the sea floor, then enters the riser to the rig on the surface, the gas bubble will begin to rise more swiftly and expand as it nears the surface and pressures decreases. The expanding gas can ignite, resulting in an explosion and fire. For reasons still under investigation, shut-off valves did not contain the leaking gas or oil.

In September 2010, BP engineers successfully removed the failed BOP from the Mississippi Canyon Block 252 Macondo well and brought it to the surface. FBI agents investigating potential crimes related to the spill were on hand to supervise and take custody of the device. Although the Macondo well is sealed with mud and cement, for additional safety the well was capped with a new BOP.

In addition to a massive rescue and search effort for crew members, BP and dozens of supporting companies and agencies dispatched engineers to the site of the disaster. BP sent more than 1,000 emergency personnel to attempt to plug the leaking undersea oil. Under U.S. law enacted in 1990, BP is responsible for cleanup costs.

After several failed attempts to stop the leaks creating the spill, in June 2010 BP officials announced that a "cut and cap" procedure was capturing approximately 15,000 barrels of oil per day. However, experts debated what fraction of the total spill was abated by the procedure. Live underwater camera pictures provided evidence of oil gushing into the Gulf from valves that engineers were forced to leave open to stabilize the cap system. Heavy seas resulting from an early season hurricane in the Southern Gulf of Mexico also interrupted surface skimming operations for more than a week.

During efforts to stop the flow of oil at the wellhead, drilling continued on two relief wells that engineers described as the best hope to permanently stop the flow of oil. Successful initial capping of the runaway Macondo well on 15 July offered engineers another opportunity to permanently seal the well. Engineers began to evaluate the potential of using a "static kill" procedure in conjunction with relief well efforts that were temporarily stalled by tropical weather. In early August, BP engineers began efforts to permanently seal the damaged Macondo well by pumping in concrete and heavy drilling mud. Instead of waiting for the completion of the relief wells, engineers opted to start a static kill (also known as bullheading) procedure by pumping in the sealing mixture through a modified well cap. The long-anticipated bottom kill procedure, which involved pumping the sealing mixture through a relief well deep into the damaged well column, was completed in September as a secondary method to permanently seal the well.

Although both BP and government officials initially downplayed the importance of determining the exact volume and extent of the spill, industry and environmental experts said accurate estimates were key to planning and assessing remediation efforts. With potential penalties under the U.S. Clean Water Act, ranging from $1,100 per barrel upwards to $4,300 per barrel in cases of gross negligence, a wide array of experts claimed that accurate assessments of the spill were legally, politically, economically, and environmentally important.

Federal scientists ultimately estimated that the multi-faceted containment efforts recovered less than 20 percent (about 800,000 barrels) of the oil spewed from the well. Based on August 2010 recovery figures and spill estimates, in addition to other losses and costs related to the spill, BP and other responsible parties also face total fines ranging from approximately $4.4 billion to $17.2 billion, even if fined for simply for the 4 million barrels of unrecovered oil. Legal experts argue that the actual range of potential fines facing responsible parties will be substantially greater, increased by fines related to wildlife protections statutes and differential application of fines for recovered versus unrecovered oil. Adverse judgments in civil actions could easily eclipse the maximum fines ultimately imposed on responsible parties.

By 24 April 2010, a rapidly expanding surface oil slick was visible in the Gulf. The U.S. Coast Guard, which has oversight of accident and cleanup operations, reported that early efforts to reduce expansion of the slick were thwarted by heavy weather. By 14 May, the slick touched barrier islands off Louisiana's Chandeleur and Breton sounds. By 24 May, oil began to wash into Louisiana wetland areas. By June, oil washed ashore along beaches from Louisiana to Florida. By July, observations of oil in inland waterways, estuaries, and lakes increased, including sightings of oil in Lake Pontchartrain, the large lake bordering on New Orleans and a source of water for the city.

Throughout the spill, the bulk of the slick remained at sea, elongating eastward in the Gulf's clockwise circulation pattern. As the oil moved eastward, so did the extent of emergency declarations. The National Oceanic and Atmospheric Administration (NOAA) models predicted that the slick, caught in the Gulf's loop current, could ultimately impact the Florida Keys, enter the Gulf Stream, and move up the east coast of the United States. On 16 May 2010, NASA and NOAA satellite imagery confirmed that a large section of the oil spill moved southeast from the site of the spill to enter the loop current. However, because of the rapid dispersion of oil at sea no large surface spill moved significantly southward in the loop current. However, dissipated globs of oil on the sea floor can also wash up on beaches and contaminate coastal areas for weeks and months following a spill. It is most likely that the majority of dissipated oil will ultimately degrade, but some of it will eventually wash up as tar balls rather than come ashore as a surface wave of oil.

After the slick at first moved northward toward wetland sections of the Louisiana coast, the U.S. Coast Guard (USCG) began setting controlled fires to parts of the slick in order to delay or diminish movement of oil into shallow water. Although such burns can eliminate 50 to 95 percent of the oil, they are not without environmental risk or cost. Oil residues can still cause pollution and marine animals and birds can be killed or injured by the fire and toxic fumes.

Hundreds of vessels immediately began skimming and containment operations. Both ships and aircraft began applying oil dispersants to the slick. Marine wildlife experts warned against indiscriminate use of dispersants because some dispersants are directly toxic to marine organisms. In addition, dispersed oil globules can also be highly toxic. Concentration is the key to a tricky environmental trade-off; cleanup engineers and crews rely on the dilution of dispersants and dispersed oil to minimize levels of toxicity. Federal agencies, including the NOAA, normally monitor applications of dispersants through the Special Monitoring of Applied Response Technologies (SMART) program. At one point, the U.S. Environmental Protection Agency (EPA) ordered a halt to the spread of selected dispersants pending further review of toxicity. The extensive use of the oil dispersant Corexit remains controversial and under scientific investigation.

Throughout the spill, federal agencies worked with state governments in Texas, Louisiana, Mississippi, Alabama, and Florida to coordinate efforts to mitigate potential damage, Louisiana officials immediately ordered placement of containment booms near environmentally vulnerable coastal areas. Booms were deployed to protect the Pass-a-Loutre Wildlife Management Area used by several migratory bird species. The spill also posed both environmental and economic peril to the white sand beaches and communities along the Alabama and Florida coasts. Beach closures would damage tourist-sensitive local coastal economies still struggling to fully recover from a string of intense hurricanes and tropical storms over the last six years.

The slick crippled the regional seafood industry, destroying or closing oyster beds and prime fishing grounds for shrimp and crab. On 2 May 2010, federal and state agencies instituted temporary bans on commercial fishing from the mouth of the Mississippi river to the Florida panhandle. By 22 June 2010, the fishing ban extended over 33 percent of the Gulf. Unable to fish, many skippers of shrimp boats and other fishing vessels volunteered to assist in cleanup efforts.

In June 2010, U.S. Fish and Wildlife Service officials reported a spike in the number of dead and oil-stained birds. Wildlife experts continued to assert that official estimates of injured and recovered wildlife were a vast undercounting of the extent of injury to an array of species and failed to account for observable reductions in many wildlife populations in the spill region. By 15 July 2010, wildlife officials and pathologists conducting necropsies on dolphins, sea turtles, and other species noted anomalies in the numbers of deaths and in the areas where dead marine life are collected. In some cases, animals were found far from their normal habitat areas. Pathologists continued to explore the exact cause of death in marine life that lacked the normal signs of oil contamination or consumption. Scientists were also continuing to map higher than normal methane levels in contaminated areas.

Thousands of birds and other marine animals were initially killed or injured by the spill. Experts contend that it will take several years of study, perhaps decades of study, to fully assess the environmental and ecological impact of the spill. Immediate areas of study include spill impacts on existing wildlife populations damage to future generation caused by poisoning or destruction of eggs and larvae. Wildlife officials point out that in comparison with worst case scenarios based on the size of the spill, however, the death toll on birds and other marine mammal is initially far lower than expected.

Along the Gulf Coast bordering the spill, residents frequently reported a light acrid smell in the air. Some reported respiratory irritation. The Environmental Protection Agency (EPA) began special monitoring and reporting of potentially toxic air pollution created by the volatile petroleum compounds. Public health officials expressed a range of concerns about health impacts. U.S. Surgeon General Regina Benjamin said that scientific predictions ranged from little or no toxic effect (especially from short-term exposure) to levels of serious concern. Although the composition of crude oil varies somewhat according to its source, crude oil is a naturally occurring brown or black liquid that is composed of a mixture of hydrocarbons and other organic compounds. Crude oil is toxic, flammable, and contains volatile organic compounds (VOCs) that have known adverse effects on human health, such as benzene, a carcinogen, and polycyclic aromatic hydrocarbons (PACs), which are toxic to the central nervous system. A substantial portion of the volatile components of petroleum, about 25 to 40 percent of the total volume of spilled oil, dissolved in the water column as oil rose to the surface or evaporated at the ocean surface.

With the undersea oil leak stopped, the surface oil slick initially appeared to dissolve quickly in the warm Gulf waters. Although tar and oil continued to wash inland, by 28 July 2010 deposits on beaches diminished and became more widely dispersed and sporadic. Both observational reports and RADAR imaging showed a near complete breakdown of the surface slick across wide areas of the Gulf. There were, however, still offshore areas of concentrated oil and tar balls.

By early August 2010, NOAA director Jane Lubchenco asserted that the majority of spilled oil was accounted for and that there were no longer "significant" concentrations of unaccounted for oil in the Gulf. NOAA officials and environmental experts were quick to clarify, however, that the full ecological impact of the spill remained unknown and that the potential for substantial future damage remained.

With areas of sea clearing, NOAA began to reopen sections of Federally controlled waters to commercial fishing.

In contrast to the initial official assurances that the oil in the Gulf was largely dissipated, on 17 August 2010 researchers at the University of South Florida announced test results showing potentially toxic concentrations of submerged contaminants in areas of the Gulf of Mexico where underwater currents previously carried plumes of oil and dispersant oil emulsions. Although the oil was not definitively leaked to the BP oil spill, plumes of oil attributed to the spill were previously observed in test areas.

In September 2010, oceanographic researchers announced the discovery of a deep layer of oil, several inches thick, hovering near the ocean floor in the Gulf of Mexico. The scientists also discovered a layer of dead shrimp and other species normally found near the ocean surface at depths of one mile or more in the oil. The deep layers of oil were found in test samples taken as far as 80 miles from the site of the Macondo well that was damaged by the explosion and fire that sank the Deep Horizon drilling rig in April 2010. Although the oil exhibited weathering characteristics that fit with the oil known to come from the damaged Macondo well, additional testing is required to conclusively link the massive oil spill with the discovered sunken oil layer. The report was in contrast to earlier government and BP reports stating that the spilled oil had been degraded by chemical dispersants and by bacteria that normally digest oil that naturally seeps into the warm Gulf waters.

In September 2010, federal officials commissioned a scientific survey and assessment of the amount of oil potentially remaining in the Gulf along with an assessment of potential environmental impacts. Initial plans called for funding of the NOAA coordinated study from a $500 million pledge by BP for oil spill related scientific research. The study is designed to eliminate confusion over conflicting claims regarding the fate of spilled oil, especially in submerged oil appearing in underwater plumes.

Scientists also expressed uncertainty about how long it would take the Gulf to recover. Evidence of the Exxon Valdez oil spill can still be found in coastal areas of Alaska. Scientists have previously measured adverse environmental impacts and food-chain disruptions extending for decades following other large spills around the world. In one case, botanists working in Mexico discovered damage to plants more than 30 years after a major spill. Biologists still note abnormalities in the behavior of crabs and other species in Massachusetts' Buzzard's Bay more than 40 years after a nearby fuel oil spill. Subsurface oil pockets—lacking the oxygen needed by a number of microorganisms that degrade oil over time—can contaminate spill areas for decades. The oil pockets impair nesting habitats and release low levels of hydrocarbon toxins into sand, soils, and water supplies. Both acute destruction and slow poisoning of protective vegetation can also spur coastal erosion.

The oil spill renewed controversy on the environmental risks of offshore oil drilling, especially in the wake of the Obama administration's decision to seek and allow greater access to offshore U.S. oil and gas resources in federal waters. Obama subsequently announced the formation of a commission to investigate the cause of the oil spill along with both the industry and government response to the disaster. Similar presidential commissions investigated the space shuttle Challenger accident in 1986 and the Three Mile Island nuclear power plant accident in 1979. Obama administration officials also pledged changes in industry oversight. Obama specifically criticized what he characterized as a "cozy relationship" between government regulators and oil industry representatives.

In response to the risks exposed by the Gulf spill, the Obama administration also declared a six-month moratorium on drilling new offshore wells deeper than 500 feet while the presidential commission conducts its investigation. Currently, approximately 600 wells in the Gulf of Mexico operate at depths greater than 500 feet. Such deepwater operations account for 80 percent of Gulf oil production. The moratorium initially stopped only new work on 33 deepwater drilling rigs. Operations at existing wells were not affected by the moratorium. After establishing new rules related to safety, certification, and licensing, the Obama administration removed the moratorium on new deepwater oil and gas drilling on 12 October, 2010.

According to the U.S. Federal Minerals Management Service, there have been more than 850 reported fires and explosions related to oil exploration and production in the Gulf of Mexico since 2001. Small spills are not uncommon from the string of offshore rigs that dot the Gulf Coast. However, federal records indicate that there has not been a confirmed spill in excess of 1,000 barrels into the Gulf of Mexico since 1996. There are more than 4,000 active offshore platforms in all U.S. waters.

On 15 June 2010, Obama delivered a speech from the White House oval office that called upon Americans to use the Gulf oil spill crisis as a springboard toward a national energy policy aimed at reducing the need for foreign oil and risky offshore drilling. Obama characterizing the need to develop alternative energy sources as a "national mission."

Obama also announced plans to develop a comprehensive Gulf Coast restoration plan. Obama directed BP officials to establish an escrow fund (a dedicated reserve of money), under the control of a third party not accountable to BP, that must be dedicated to paying compensation and other damage claims. BP officials subsequently announced that they would escrow $20 billion toward the compensation fund. BP pledged to pay $5 billion to the fund each year for the next four years. The fund is not intended to cover fines or cleanup costs. BP also established a $100 million fund to pay workers on other rigs now unemployed due to the drilling moratorium.

In July 2010, four major oil companies (Chevron, ConocoPhillips, ExxonMobil, and Royal Dutch Shell) voluntarily pledged $1 billion to create the Marine Well Containment Company (MWCC), an entity charged with creating and maintaining an emergency response team able to respond to future deepwater oil spills in the Gulf of Mexico. Expert analysts said the move was in response to criticism of lax industry preparations to cope with deepwater spills, and as part of an effort to gather public support to combat Obama Administration efforts to enforce a partial moratorium on some forms of offshore drilling. MWCC, chartered as a nonprofit company, set a goal of being able to contain spills at depths up to 10,000 feet and to develop the capacity to recapture up to 100,000 barrels (4.2 million gallons) of oil a day. MWCC will also fund research efforts related to spill tracking and remediation.

"Gulf of Mexico Oil Spill." Global Issues in Context Online Collection. Detroit: Gale, 2010. Global Issues In Context. Web. 26 Oct. 2010. http://find.galegroup.com/gic/infomark.do&contentSet=GREF&idigest=e1fdaa8c36237e8a62b83c1487ae9de8&type=retrieve&tabID=&prodId=GIC&docId=CP3208520335&source=gale&userGroupName=miss475

2&version=1.0.

Christin Robev October 27/10