When Hurricane Katrina struck the Gulf Coast in August, no one was immune from its rage. The hurricane hit oil and gas infrastructure particularly hard. More than 100 platforms were destroyed or lost, major pipelines were shut down, and refineries and oil storage sites lost power and were flooded and heavily damaged. While thousands of people rushed out of the area, struggling to avoid rising flood waters, some folks were rushing in. They were hoping to prevent or at least quickly clean up what would become Americas largest oil spill since the 11-million-gallon Exxon Valdez spill in Alaska in 1989 (see sidebar, page 35 Print Exclusive).
The Katrina factor
Damage to oil facilities from Hurricane Katrina caused four medium spills (more than 10,000 gallons) and 134 minor spills, in which 8 million gallons of oil leaked onto the ground and into waterways from Louisiana to Alabama. The largest single spill was at the Bass Enterprises Production Company site in Cox Bay, La., where 3.78 million gallons of oil spilled. Another large spill was at the Chevron Empire oil terminal in Buras, La., where the roof of one storage tank was ripped off and the foundation of another ripped out, leaking 1.4 million gallons of oil.
At the Chevron Empire oil terminal in Buras, La., oil spill responders used a controlled burn to clean up oil that spilled out of several of the facilitys tanks following Hurricane Katrina. The storm caused at least 8 million gallons of oil to leak at a number of different facilities, making it the second largest U.S. oil spill. Image courtesy of U.S. Coast Guard/Petty Officer 3rd Class Robert M. Reed.
Hundreds of workers responded to the spills within a day of the hurricanes strike, despite many having lost their homes, says Mickey Driver, a spokesman for Chevron. Besides ensuring the safety of our personnel, our first priority was to respond to those spills, he says.
And thats true of all the energy companies in the area, Driver adds, despite some incredible logistical challenges, such as no electricity, water, food, sewage, fire department or emergency services, phone lines or other communication, and no place for anyone to stay. We had to keep flying in people daily and housing others on barges, he says.
Additionally, Marine Spill Response Corporation (MSRC), an industry-funded nonprofit oil spill cleanup organization, brought in seven vessels (with 38 berths apiece) designed for spill response that served as command and control centers following Katrina, says Judith Norell, a spokesperson for the organization. The ships served as sleeping and mess halls, logistical and staging support, communications facilities and spill cleanup headquarters, she says. MSRC acts sort of like your local fire department, in that [the oil companies] fund us, hoping they never have to call us, but were ready to provide spill-response services if they need us, Norell says. The organization responded to 32 individual incidents related to Katrina, which was one of the most challenging cases that MSRC has faced, she says.
In addition to the logistical and communications challenges Katrina caused, the storm also challenged responders by causing many different types of spills, from the tank spills to capsized fishing boats, in many different environments, from the Mississippi River to marshes to tank farms. Our entire team was deployed to multiple sites, says Tom Callahan, deputy division chief of the Hazardous Materials Response Division of the National Oceanic and Atmospheric Administration (NOAA). We havent had that many people in the field since the Exxon Valdez.
A pretty key component of the oil spill response team, Callahan says, NOAA provides scientific expertise to the U.S. Coast Guard and Environmental Protection Agency (EPA) during an oil spill. Although many governmental agencies are involved in spill response, EPA has oversight of any spills inland, and the Coast Guard oversees spills in any coastal areas or major navigable waterways. In some cases, such as Katrina, spills may involve both inland and coastal areas, in which case both agencies may oversee the coordination of the response. Together, the government agencies, alongside the responsible parties, local officials and cooperative organizations such as MSRC, form a joint command to figure out a course of action, says Jim Clark, head of ExxonMobils Oil Spill Research Program.
Spill responders have a wealth of different technologies at their disposal to deal with oil spills. Mechanical technologies, such as tools to contain the oil, are the most widely used in the United States, but newer technologies, such as chemicals that disperse the oil, are gaining ground, Clark says.
One cleanup tool is a mechanical boom, which is essentially a floating barrier with a skirt, kind of like curtains, placed around a leaky tanker or an oil slick, Callahan says. As oil floats on the water surface, a boom collects it within the barrier. The oil can then be scooped up by tools such as skimmers or absorbed using sorbents. Skimmers take oil off the water surface, much as someone would skim the fat off gravy using a sieve. Sorbents, which can be natural materials such as peat moss, straw or clay, or synthetic materials such as plastic, soak up oil from the surface of the water.
Alternative technologies are also available in the toolbox, Callahan says, including chemical dispersants that break down oil to distribute it throughout the water column, biological agents (such as plants and bacteria) that speed up the degradation rates, and in situ burning, which involves burning the oil slick on the water surface to prevent its spread. Once oil hits a shoreline, additional technologies can clean up the ground, such as pressure washing and vacuuming or suctioning up oil.
Before the joint command decides what technology (or suite of technologies) to employ at a site, Callahan says, there are five things we need to know. The first is what type of oil has been spilled. Each type of oil has distinct physical and chemical properties that affect the way it spreads and breaks down, and the hazards it poses. For example, light refined products such as gasoline and jet fuel are highly volatile so they naturally evaporate faster than crude oils, but theyre also more toxic to the environment and pose a greater fire hazard.
Secondly, the responders need to look at how much oil was spilled. The amount spilled largely dictates the type of cleanup technology to be used. For example, sorbents work very well to clean up small spills or remnants of spills, but do not work as well on very large spills, where booms might be a better solution.
Next, responders need to figure out where the oil is going its trajectory and whether it will evaporate or disperse. Surface tension on the seas, based on wind currents and temperatures among other factors, helps control how fast oil will spread and greatly controls what type of technologies work best. Choppy seas or fast currents, for example, can render booms and skimmers relatively useless but might be perfect for dispersants or sorbents, Callahan says.
Responders also have to look at the type of environment the oil is headed for, Callahan says, to know what type of technologies can or cannot be used there. For example, he says, sandy beaches are easier to clean up than marshes or protected embayments, which are highly sensitive environments where responders cannot go tramping about with shovels and rakes. Responders also consider the impacts of the spill and their potential responses on the habitats involved, such as fisheries or marine reserves.
Lastly, responders must assess the balance of tradeoffs of the particular technologies chosen, Callahan says, in deciding how to respond. For example, some of the alternative technologies, especially dispersants, are still somewhat controversial, says Don Aurand, vice president and senior scientist at Ecosystem Management & Associates, Inc., an environmental consulting firm in Maryland. Dispersants put oil into the water column, thus providing more exposure to fish, he says. A lot of people view that as an issue. Then again, he says, dispersants protect shorelines from oil. The goal is to minimize overall damage and promote recovery by making intelligent choices.
During a spill, responders generally will utilize several different technologies. During the Katrina cleanup, for example, responders used almost all of them. At Chevrons Empire terminal, most of the oil was contained onsite where it naturally dispersed, according to the Coast Guard. Responders contained the rest of the oil using mechanical booms, and cleaned it up with a skimmer and in situ burning. Much of the oil at Empire spilled out in marshes, which previously had been overrun by an invasive plant species, Callahan says, so in situ burning killed two birds with one stone wiping out the oil as well as the invasive species. Some other cleanup sites also used sorbents, but no sites employed dispersants, as that particular technology is only used in the deep sea.
All of the players in the command group stay involved in the process from initial cleanup through restoration of affected sites, Callahan says. Months after Katrina, NOAA is still involved in cleanup and restoration projects at several of the spills.
The big picture
There are two realities of oil spills, Aurand says: They are inevitable but unpredictable, and youre not going to be able to clean it all up with mechanical recovery techniques. So the emphasis, he says, has to be on using whatever combination of technologies necessary to leave the smallest footprint, and on ensuring that good contingency plans are in place for any possible spills.
NOAA responds to about 100 incidents every year on average, varying in size and impact, Callahan says. The Coast Guard responds to many more spills, he says, but this would include smaller events where it is more of a law enforcement action that does not call for NOAA scientific support.
This past year was certainly anomalous in terms of the number of spills, especially since 1990, when Congress passed the Oil Petroleum Act of 1990 into law (following the Exxon Valdez spill), says Robin Rorick, a senior regulatory analyst with the American Petroleum Institute, an industry trade group in Washington, D.C. Among other provisions, the act established double-hull provisions for tankers, strengthened spill response penalties and established the Oil Spill Liability Trust Fund.
The fund, originally established by a per-barrel tax on the petroleum industry, is intended to be an immediately available source of funding should a spill occur or should a company not have enough money to cover the cleanup costs, Rorick says. The fund is also used to finance oil spill prevention and response activities of various federal agencies as well as research into new and improved oil spill response technologies. Overall, industrys record on oil spills is excellent, especially considering the amount of petroleum products [that are] produced and transported in our country, but it is not perfect, Rorick says. That said, industry is continually striving to improve its oil spill record if not make it perfect.
Were always looking at ways to optimize spill response strategies, says Clark of ExxonMobil, from identifying oil slicks in the water to sending the appropriate cleanup equipment. Although the actual cleanup technologies have been in use for the last several decades or so, the technologies have steadily advanced and are continuing to advance today, says Joseph Mullin, manager of the Minerals Management Service (MMS) Oil Spill Response Research Program, which is financed by the trust fund.
Booms and skimmers that used to move at 0.5-knot speeds, for example, now reach 3 knots, covering four times as much ground in the same time, Mullin says. And recently, research and development programs at NOAA, MMS and ExxonMobil, among others, have largely focused on developing computer models for oil spill tracking and improving remote sensing and surveillance, as well as conducting dispersant effectiveness experiments at Ohmsett, the National Oil Spill Response Test Facility located in Leonardo, N.J.
Were using advanced computer models now to develop scenarios for the trajectories of oil spills, and also to look at the chemistry of what happens as the oil moves, to help evaluate treatments, Clark says. Temperatures, winds and other seasonal weather conditions all affect the trajectories of where an oil spill will drift, so better modeling will help determine how to intercept the spill. Additionally, chemical and physical properties of oil change as it moves through water, with or without the aid of dispersants, he says, so it is important to track exactly what is happening to know what the best cleanup technology is.
Remote sensing is also aiding in the tracking of oil. Researchers use radar to track oil spills at night or in cloudy conditions, to direct cleanup equipment to the thickest areas first, and to determine the type of oil spilled, Clark says.
Researchers are also working on new ways to find oil under ice, Mullin says. Currently, pipelines underneath ice in Alaska and the North Sea pump oil onshore, requiring the drilling through ice to find a spill, he says. Thats not a good option. So, ExxonMobil is working on using ground penetrating radar to look through the ice for spills, which requires no drilling. They have a permit to test the technology in Norway in April.
Practicing oil spill scenarios contingency planning is also a big part of the oil spill response, and a part that takes place long before a spill occurs, Clark says. All the oil companies make a concerted effort to ensure their contingency plans are updated and using the best technologies. Avoiding spills is impossible, Callahan adds, so being prepared is the best medicine.