Fourteen years after the devastating BP Deepwater Horizon disaster, we find ourselves reflecting on the effectiveness of our response to the oil spill and asking: If a similar incident were to occur today, would we be better equipped to clean it up? The Deepwater Horizon oil spill on April 20, 2010 is one of the most infamous environmental disasters in history. An explosion on an offshore drilling rig operated by BP caused an explosion that killed eleven workers and caused approximately 4.9 million barrels of crude oil to spill into the Gulf of Mexico over 87 days. The spill devastated marine life, killing more than one million seabirds and leaving a lasting scar on local communities. Despite all efforts, only one-third of the oil could be recovered or dispersed. The remaining crude oil seeped into the ocean, beaches and wetlands, causing long-term ecological and health impacts. In the years since, there have been many advances in oil spill response technology, but experts are divided on whether they will significantly improve the outcome of another large-scale spill. The Challenge of Oil Spill Cleanup
Oil spills are a very common occurrence. NOAA, the U.S. National Oceanic and Atmospheric Administration, responds to more than 150 oil spills each year. While most spills are relatively small, large spills remain a constant threat, whether tanker accidents, leaking pipelines or sunken ships.
When oil spills into the ocean, it spreads quickly, and forms a thin layer over a wide area. The priority is always to stop the source of the spill, whether it’s a ruptured pipeline, a leaking tanker or a damaged well. Then, efforts turn to recovering the oil at sea. However, oil spreads faster than recovery equipment can keep up, making it a race against time. Once it reaches shore, the damage to the environment is much more severe and cleanup is costly.
The most widely used method of cleaning up oil spills involves skimmers, which are boats that skim oil off the water’s surface. However, the effectiveness of this method is limited. In the case of the BP Deepwater Horizon spill, skimmers were only able to remove about 3% of the oil. “Floating oil dissipates very quickly, and there is a limited amount of time—days—that the equipment is at sea to be effective,” says Doug Helton, regional supervisor for NOAA’s Emergency Response Division. Even with better technology, the bow wave created by the moving skimmer vessel can push oil away, reducing recovery efficiency.
The role of innovation
Since the Deepwater Horizon disaster, researchers have been exploring new materials and techniques to improve oil recovery. From laser-treated cork to graphene-based sponges, the focus has been on finding materials that attract oil while repelling water. However, these materials have been tested mostly in small-scale scenarios and are not yet practical for large spills. Handling and disposing of oil-soaked materials also presents a significant logistical challenge.
One promising innovation comes from Guihua Yu and his team at the University of Texas at Austin. They have developed a super oleophilic gel that can separate oil from water with 99% efficiency. This gel, when applied to a mesh filter, allows for continuous oil recovery. Their prototype involves a conveyor system attached to a ship, which collects oil from the water surface and separates it using heat, allowing the same material to be reused. Although this sounds promising, it has only been tested on a small scale, and many practical challenges remain, such as addressing the bow-wave effect that pushes oil away from the ship.
Limitations of Current Methods
Despite advances, the methods we have for dealing with large-scale oil spills are still fundamentally limited. Burning the oil is one method that was used to remove about 5% of the oil during the BP spill. However, burning requires specific conditions, such as calm seas and high concentrations of oil. It also introduces new environmental hazards, such as air pollution. Workers involved in cleanup efforts during the BP spill reported significantly higher rates of respiratory problems, such as asthma. Toxic fumes from burning or vaporizing oil can pose serious health risks to cleanup workers and nearby residents.
Dispersants, which are chemicals sprayed on oil to break it up into smaller droplets, were used extensively during the Deepwater Horizon spill. While dispersants can help prevent oil from reaching shore, they also carry their own risks. The use of a dispersant called Corexit was criticised for its limited effectiveness and potential environmental harm. Studies have shown that the combination of dispersants and sunlight increases the toxicity of the chemicals, causing more harm to marine life than oil alone.
Bioremediation, which involves using micro-organisms to break down oil, was explored as a more natural cleanup method.