The State of Oil Spill Cleaning Technology

Since the Exxon Valdez oil spill wreaked havoc on the Alaskan shoreline over 20 years ago, there have been few advances in technology for cleaning up after an accident. Here is an overview of the cleanup technologies on hand for the Deepwater Horizon spill.

The Deepwater Horizon saga playing out in the Gulf of Mexico is officially a Humpty Dumpty situation. On Sunday, President Barack Obama arrived in Louisiana to reaffirm the government's "all hands on deck" approach to combating the spill. All the king's horses and all the king's men are mustered in the Gulf, in the form of thousands of oil spill responders, a Coast Guard strike force a hundred vessels strong, 100,000 meters of containment boom, the Air Force's 910th Airlift Wing, the Secretaries of the Interior and Homeland Security and fleet of fisherman-cum-boom-layers, and one-third of the world's oil dispersant supply, just to name a few.

In addition to the massive accumulation of manpower in the region, federal and local authorities, working in conjunction with BP, which operated the now-collapsed rig, have deployed every possible technological response in an attempt to stem the oily tide, which is approximately 130 miles long and 70 miles wide, both beneath the sea and on the surface.

The Situation Underwater

At present, it is estimated that the three leaks, located 50 miles from the Louisiana coast, and 5000 feet below sea level, are spewing oil at a rate of 200,000 gallons per day. BP is trying to stop the flow with a three-pronged approach. Initially, a number of remote-controlled robotic submarines were dispatched to the gulf floor in an attempt to close a series of valves that would halt the leakage. Thus far, these efforts have proved fruitless, with one BP official telling ABC news, it's like trying to perform "open heart surgery … in the dark."

While the robots toiled undersea, BP also took other, less immediate steps, including positioning another rig over the leak site that will drill a "relief well" meant to divert the flow away from the Deepwater Horizon leaks. In the meantime, efforts are also underway to construct three massive cement-and-steel capping "domes." These will act like 40-foot tall, 70-ton vacuum attachments, which will cap the leaks and channel the oil up pipes to recovery tankers on the surface. But the domes are still days from being completed and have never been tested at such great depths.

And on the Surface

With its current leakage rate, experts predict, the Deepwater Horizon spill could eventually total nearly 20 million gallons of oil. For comparison, the amount of oil spilled by the Exxon Valdez in 1989 was 11 million gallons. To mitigate potential damage to the Gulf Coast and to prevent environmental devastation on the scale of that infamous Alaskan spill, spill responders are using every weapon in their arsenal.

The Cleanup: A Three-Pronged Approach

According to Elise DeCola, an oil spill specialist with the environmental consultancy Nuva Research, there are three ways to combat an oil slick on the open sea. The first tactic is the so-called mechanical approach, which comprises the use of a boom to corral and deflect oil and skimmers to collect it.

"That's the preferred approach because it's the only one that takes the oil out of the environment," DeCola says. "It's labor-intensive and it's equipment-intensive. With a successful mechanical recovery, you might get 20 percent of the oil that you encounter."

The second approach is to apply dispersants to the slick. These detergent-like solvents are typically deployed from sea vessels operating around the slick, or from aircraft overhead. Additionally, BP and the National Oceanic and Atmospheric Administration are attempting to apply dispersants below sea level using robotic submarines, though the efficacy of this tactic is still undetermined. When dispersants mix with the slick, it breaks the oil into droplets, suspending it in the water column to be dealt with naturally. "They've been applying these in the Gulf," DeCola says. "An off-shore blowout is the textbook case for using dispersants because you don't have to worry about misapplication or hitting a marsh area." As of May 2, more than 156,000 gallons of dispersant have been applied to the slick, with an additional 75,000 gallons available.

The final tactic being deployed in the Gulf is in situ burning. Oil is corralled using booms to thickness where enough volatiles are present to sustain a controlled burn. Once the oil is burned it forms a tar-like substance that can either be manually removed from the water, or left to decompose naturally, similar to dispersant-treated oil. The Coast Guard conducted an hour-long test burn last Wednesday, but unfavorably strong winds and rough seas have prevented any further in situ burning.

Dr. Gerald Graham, a 30-year veteran in the oil spill business, says all three standard approaches remain essentially the same as they were at the time of the Exxon Valdez spill, incremental improvements have been made in all areas. Booms are more resilient in fast currents, for example, and dispersants are considerably less toxic than they once were. The biggest improvements, according to Graham, have come in information technology, and how responders collect and use data—oil spill response atlases, spill-trajectory modeling, satellite spill sensing, and using laser fluorosensors to detect spills from aircraft have all become commonplace in the years since Exxon Valdez.

Moreover, says Graham, the responders using these instruments are now trained professionals, whereas two and three decades ago, it was "a dirty job for someone who was about to retire. Nobody wanted to do it."

"It's still a lot of grunt work," Graham says. "It's still throwing personnel and equipment at the spill and dealing with Mother Nature and her whims."

Next-Gen Cleaning Tech

Extreme Spill Technology's "High Speed" Skimming Vessel Mechanical clean-up technology tends to work only in placid waters. Booms and skimmers can be rendered ineffective and unsafe in currents of more than 1 knot and waves exceeding 1.5 meters. According to David Prior, CEO and lead designer at Extreme Spill Technologies, his boat—the method for which has been successfully demonstrated for the Canadian Coast Guard—can not only handle rough seas, it can also travel at much higher speeds.

Case Western Reserve's Aerogel In February researchers at Case Western Reserve University unveiled a sponge-like material of their creation composed of 2 percent clay, 2 percent plastic and 96 percent air. Their lab tests demonstrate how the sponge (called Aerogel) when applied to polluted water is capable of absorbing the oil and leaving behind the water. It can then be squeezed clean so that the oil can be recycled.