With efforts so far unsuccessful to stop oil from flowing from the site of a rig accident in the Gulf of Mexico and the spill floating closer to shore, U.S. authorities said Tuesday that they're considering a controlled burn of the oil on the water's surface.
"We're prepared to use every tool in the tool kit" to fight the oil spill as far off coast as possible, said Rear Adm. Mary Landry, commander of the Eighth U.S. Coast Guard District, who is leading the response effort.
An "in situ burn" of the oil would be "a very, very controlled situation but could be a very effective method" of limiting impact of the Gulf oil spill, Landry said.
Underscoring the seriousness of the situation, she said: "If we don't secure this well, this could be one of the most significant oil spills in U.S. history."
(Related blog: "Who's Still Spilling Oil in the Seas?")
Attempts to Stop Gulf Oil Leak Unsuccessful
The oil spill is now just 20 miles (32 kilometers) from the coast of Louisiana. Offshore of the Delta National Wildlife Refuge—home to American alligators, brown pelicans, peregrine falcons, and piping plovers—workers were positioning long, tubelike booms in the Gulf on Tuesday in an attempt to keep any approaching oil at bay.
Oil has spread over an area 100 miles (160 kilometers) long and 45 miles (72 kilometers) wide (see a map of the Gulf of Mexico oil spill).
Authorities will not estimate how much oil has spilled altogether since the April 21 explosion at the Deepwater Horizon oil rig site, which is leased to the energy company BP. But oil continues to flow at the rate of 1,000 barrels (42,000 gallons, or 160,000 liters) a day from damaged pipes 5,000 feet (1,520 meters) underwater, the Coast Guard's Landry said.
BP's efforts to use remote-controlled submersibles to stop the spill have not proven successful so far. Planned back-up measures—such as sealing the seafloor leak site with a dome and then piping the oil to a tanker, or drilling a relief well to permanently seal the leaking well—could take weeks to months to execute, BP said.
To Burn or Not to Burn the Oil
The Coast Guard's Landry said authorities will decide on Wednesday whether to opt for the strategy of burning the oil.
In a controlled burn, towing boats and fire-resistant booms are arranged in a U shape to contain spilled oil before it is ignited, according to a description of the oil-containment measure (PDF) on the Web site of the U.S. National Oceanic and Atmospheric Administration, which is aiding in the spill response. The process may be repeated multiple times.
Indeed, Landry said that burning would remain a tool under consideration as long as oil was still leaking.
Authorities are drawing heavily on a 1993 experiment conducted off the coast of Newfoundland, Canada, which showed that this type of controlled burn can eliminate 50 to 99 percent of the oil collected.
The heat generated by the burning oil—a temperature of 1,800°F (982°C) was measured at the top of the boom at the Newfoundland burn—will cause the smoke to rise several hundred to several thousand feet and at the same time be carried away by the prevailing winds, NOAA's report said.
Oil Burn Effects Similar to Those of Forest Fire?
Charlie Henry, scientist with NOAA and member of the oil-spill response team, said the plume of black smoke will be the biggest environmental impact from such a burn. The smoke will be mostly made up of carbon dioxide and water, but will also contain particulate matter and soot.
"It will be similar to other fires with organic material"—such as forest fires, he said.
The Coast Guard's Landry said even if a burn is begun, it can be stopped at any time. She added: "Right up until the time we initiate the fire, if we have any concerns, we will balance those against the benefit of reducing the amount of oil."
The Gulf spill is still small compared to the worst oil spill in U.S. history, the Exxon Valdez disaster of 1989, in which 11 million gallons (42 million liters) were released.
But this well is 5,000 feet (1,524 meters) underwater. Landry said members of the federal-industry response team were not aware of another oil spill in history that had to be fought in water so deep.