With the Gulf of Mexico oil spill now the worst in US history, public pressure is growing on BP to contain and remove the ever-spreading slick. There are numerous potential cleanup methods, some that are already being used and others that are... well, rather non-traditional.
BP has said it had received nearly 10,000 suggestions on alternate cleanup methods by the end of May and is seriously looking at 700 of them. With estimates of the total spilled so far ranging from around 700,000 barrels to over 2.5 million barrels, it will be a massive job.
So, what are some of the techniques—both traditional and non-traditional—that could be used to clean up the oil spill? Click ahead to find out!
By Paul Toscano and Daniel Bukszpan
Posted 9 June 2010
Chemical dispersants, which have been used throughout the oil spill, are sprayed by boats, aircraft and workers on the shore. Chemical dispersants pull apart oil particles suspended in water, reducing the oil slick to droplets that can be degraded by naturally occurring bacteria.
The major benefit of this technique is that the dispersants can be applied over a large area from specially-fit airplanes or helicopters. When the chemicals are applied, dispersed oil is significantly less toxic. However, because the chemical properties of leaked oil will change over time, dispersants may lose their ability to break apart the oil. There are also concerns about the dispersants themselves , which are also toxic, damaging the environment.
The use of underwater dispersants was purely experimental when the BP oil spill first occurred. Similar in nature to traditional dispersants, the idea is that underwater dispersants attach to the oil before it can reach the surface, thus minimizing the amount of oil that eventually lands on shore.
This technique, however, requires the use of remote vehicles to apply the chemicals, which may be less effective at extreme depths. Being that this technique is not completely tested, critics worry that breaking up oil at extreme depths may release more toxic components into the water and could potentially damage the underwater ecosystem.
Controlled burns have been conducted throughout the Gulf oil spill. A fireproof boom corrals leaked oil into smaller, more dense pockets that can be ignited remotely from the air and burned off. The process of burning removes large portions of oil from the water's surface, keeping it away from the shoreline.
This technique must be conducted soon after the oil has been spilled, however, and can be severely affected by bad weather. During the current spill, controlled burn operations had to be postponed when waters made this technique dangerous. Controlled burns also produce columns of smoke, which shift the environmental impact from the sea to the air.
Another technique is using booms and skimmers to remove oil from the water's surface. Booms are used to collect oil in concentrated areas, while skimmers separate the crude from the water.
The efficiency of skimmers is highly dependent on sea conditions and the presence of debris, which can both pose serious roadblocks to these techniques.
Sorbent materials are possibly the most talked-about alternative to traditional oil recovery efforts But according to the EPA, they are most often used in small spills or to remove the final traces of a large spill. Sorbent materials absorb oil in varying degrees, with some materials swelling more than 50 percent. Although various sorbent materials have been proposed, government and BP officials have so far only officially "considered" these materials for use in cleaning the spill.
The major concern with sorbent materials is that although they absorb the oil, the materials must be retrieved, which may prove extremely difficult, and could potentially make the situation worse.
There are three distinct types of sorbent materials:
Natural organic sorbents can soak up between 3-15 times their weight, but may sink as a result and tend to be difficult to collect. Examples of natural sorbents include peat moss, straw, sawdust, feathers and even ground corncobs.
Natural inorganic sorbents like clay, perlite, glass wool, sand or volcanic ash all can soak up 4 to 20 times their weight in oil. These substances have similar concerns as natural organic sorbents, but are also inexpensive and available in large quantities, although they are not used on the water's surface.
Synthetic sorbents are similar to plastics and are designed to soak up liquids into their surface and can absorb liquids into their solid structures that causes the material to swell. According to the EPA, most synthetic sorbents can absorb up to 70 times their weight in oil.
The current cleanup is even more pressing because of the fragile coasts and inlets of Louisiana, which are mostly pristine marshlands. According to a 1995 report produced by the NOAA, coastal marshes have unique characteristics that make cleanup efforts a risky proposition that could further damage endangered areas in addition to the toxic oil. The report suggests several methods that have been used to clean up oil spills in the past, but notes that each carries individual risks and in most cases, mere human interaction and mobilization of equipment damages the environment in other ways.
Several major techniques include:
Vacuum/pumping, which removes pooled oil on marsh sediment or the surface of water
Low-pressure flush, which pushes oil towards collection points where other equipment is operating, like skimmers or vacuums
Vegetation cutting, in which plants are cut and removed so that other techniques can be effectively employed, however, erosion and damage to fragile sediment and existing roots may limit or even delay recovery.
Bioremediation, a potential low-impact cleaning technique, uses microorganisms and their enzymes to facilitate decomposition. Nitrate or sulfate fertilizers are used to facilitate decomposition.
Used in nearly every oil spill, the methods of manual or mechanical cleanup are the down-and-dirty techniques employed when oil spills get particularly messy. Manual cleanup consists of placing workers on the coast, armed with shovels, rakes and gloves to collect oil that has run ashore. Mechanical cleanup requires heavy machinery and is used in areas that are plagued by heavy oiled beaches, or areas which are thick in debris.
Although time-consuming, manual cleanup is preferred, as unskilled workers with minimal training can be employed in large numbers to clean affected areas. The use of heavy machinery can quickly clean up large areas, but the use of bulldozers, trucks and digging equipment can damage the affected areas in addition to the oil.
In some areas, the environmental impact of cleaning up a spill could potentially outweigh the benefits of cleaning certain areas, especially if these places are highly dense with vegetation or relatively remote. Wave action, naturally occurring microorganisms, sunlight and natural water dispersion all contribute to break down oil leaked into the ocean.
Although relying on natural forces and "doing nothing" may be hard for outsiders to swallow, in some cases it is the best environmental option. For many of the cleanup options available to crews, "natural recovery" is an important component
Several devices have been proposed to BP that can separate—sometimes in large volumes—oil from water, offering a potentially expedient method of cleaning the water. Companies like EVTN showcase technologies like their voraxial separator (CNBC Video), which creates a vortex that captures the oil, while pushing clean water outwards.
Other proposals include a centrifuge device pushed by actor Kevin Costner. BP has only said it is considering the proposed technologies.
A gelling agent is a chemical used to solidify spilled oil, making it easier to collect. Using the motion of the sea, the gelling agent turns the oil into a rubbery substance that can be easily removed from water with nets, suction devices or skimmers.
The problem with this method is one of quantity. Three times as much gelling agent as oil is needed for the desired effect to take place, and if BP's worst-case estimate is correct, then the slick in the Gulf of Mexico would require nearly half a billion gallons of solidifier. This is simply too impractical to transport and apply to the affected area.
Biological agents increase the rate at which oil naturally biodegrades. During this process, known as bioremediation, chemical agents, fertilizers and microorganisms are applied to oil, which breaks it down into a simpler and more easily removed compound.
Spilled oil must be cleaned up quickly to reduce potential damage to the environment. Unfortunately, biodegradation is a time-consuming process that can take years, especially in the case of a slick as large as the one in the Gulf of Mexico.
For more on bioremediation and a specific technique: Chemical-Eating Microbes Might Clean-Up Gulf Oil
Road construction companies use hay to control soil erosion along highways and back roads. As it turns out, hay can also be used to soak up oil spills and leave clean water behind.
To protect against the effects of the BP spill, Walton County in the Florida panhandle recently entered into an agreement with CW Roberts Contracting, a local road construction company, to use hay to mop up the oil creeping towards its beaches. Originally, the company had offered this low-tech cleanup solution to BP, but they were turned down.
Most experts believe that if techniques like this were used in the water on a large-scale, they could potentially compound the problem, as the oil-soaked hay itself would need to be retrived over a vast area.
Early on in the BP crisis, human hair was discussed as a possible material for sopping up the oil. Matter of Trust, a nonprofit environmental organization, has partnered with thousands of salons all over the world to use their clippings, which would normally get swept up off the floor and thrown in the trash.
Instead, Matter of Trust collects it, stuffs it into mesh or nylon casings and creates improvised containment booms to control oil spills.
One form of bioremediation involves the use of fungi to remove pollutants from contaminated areas. This is known as mycoremediation, a term invented by biologist Paul Stamets. His field of study is mycology, the study of mushrooms, which are used during mycoremediation to decontaminate polluted areas. Mushrooms secrete acids and enzymes that aid in the decomposition of complex organic contaminants, making them ideal for use in oil spills.
In an experiment involving soil contaminated with diesel oil, Dr. Stamets’ team treated the soil with oyster mushrooms, which broke down almost all of the oil into nontoxic components after only four weeks.
Pine shavings are mostly known guinea pig owners who are lining the bottom of their pets’ cages. Their natural absorbency makes them ideal for soaking up pet waste, but could they work for other forms of waste as well?
Pine shavings were used to clean up a hydraulic oil spill at Hancock Sawmill in Maine in 2005. The shavings allowed workers to contain the spill and soak up the oil, which was then burned in an incinerator. This cleanup was conducted entirely by Hancock employees with no assistance whatsoever from the state’s Department of Environmental Protection.
While the shavings were effective in this one very small context, it is not known how effective they would be in a multi-million-gallon oil spill the size of the state of Vermont. Also, removing the shavings from the water would be difficult.
Dr. Joseph A. Resnick is a former NASA scholar and the inventor of bioremediation technologies, such as Bio-Boom, Oil-Buster and E-SeaKleen. His inventions were used in the cleanup of the Exxon Valdez, and they are the only biological products permitted in California or the Chesapeake Bay.
Resnick’s inventions are being used at the Deepwater Horizon site. They use a technology known as PRP/WAPED (Petroleum Remediation Product and Water Pollution Eradication Device), which consists of microscopic balls of beeswax that contain pseudomonad bacteria and range in size from 0.25 to 0.65 micrometers. The bacteria eat the hydrocarbon compounds found in crude oil, and they can be used in ecologically sensitive areas where conventional cleanup methods won’t work.
As the crisis in the Gulf has escalated, suggestions for ways to cap the leak have become more radical. Using a nuclear blast to seal the well is one such suggestion. The idea is not unheard of. The Soviet Union used the extreme heat of nuclear explosions to seal gas wells with melted rock on at least five occasions between 1966 and 1981.
However, the Obama administration has shot the idea down, and with good reason. Engineers have suggested that a nuclear explosion could destroy the wellhead, making the leak impossible to seal. Most importantly, detonating a nuclear device on land to seal a gas well is an entirely different proposition than using one beneath the sea floor to seal an oil well. A blogger for Toronto’s National Post summarized the dangers of this method succinctly when he asked, “What’s worse than an oil spill? A radioactive oil spill.”