NOAA's Response and Restoration Blog

An inside look at the science of cleaning up and fixing the mess of marine pollution


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Five Years After Deepwater Horizon, How Is NOAA Preparing for Future Oil Spills?

The Deepwater Horizon Oil Spill: Five Years Later

This is the ninth and final story in a series of stories over the past month looking at various topics related to the response, the Natural Resource Damage Assessment science, restoration efforts, and the future of the Gulf of Mexico.

Oil in a boat wake on the ocean surface.

Keeping up with emerging technologies and changing energy trends helps us become better prepared for the oil spills of tomorrow, no matter where that may take us. (NOAA)

When the Exxon Valdez tanker ran aground in Alaska and spilled nearly 11 million gallons of crude oil in 1989, the world was a very different place. New laws, regulations, and technologies followed that spill, meaning future oil spills—though they undoubtedly would still occur—would do so in a fundamentally different context.

This was certainly the case by 2010 when the Deepwater Horizon oil rig suffered an explosion caused by a well blowout in the Gulf of Mexico. Tankers transporting oil have become generally safer since 1989 (thanks in part to now-required double hulls), and in 2010, the new frontier in oil production—along with new risks—was located at a wellhead nearly a mile under the ocean surface.

Since that fateful April day in 2010, NOAA has responded to another 400 oil and chemical incidents. Keeping up with emerging technologies and changing energy trends helps us become better prepared for the oil spills of tomorrow, whether they stem from a derailed train carrying particularly flammable oil, a transcontinental pipeline of diluted oil sands, or a cargo ship passing through the Arctic’s icy but increasingly accessible waters.

So how is NOAA’s Office of Response and Restoration preparing for future oil spills?

The Bakken Boom

Crude oil production from North Dakota’s Bakken region has more than quadrupled [PDF] since 2010, and responders must be prepared for spills involving this lighter oil (note: not all oils are the same).

Bakken crude oil is highly flammable and evaporates quickly in the open air. Knowing the chemistry of this oil can help guide decisions about how to respond to spills of Bakken oil. As a result, we’ve added Bakken as one of the oil types in ADIOS, our software program which models what happens to spilled oil over time. Now, responders can predict how much oil naturally disperses, evaporates, or remains on the water’s surface using information customized for Bakken’s unique chemistry.

We’ve also been collaborating across the spill response community to boost preparedness for these types of oil spills. Earlier this year, NOAA worked with the National Response Team to teach responders about how to deal with Bakken crude oil spills, with a special emphasis on health and safety.

The increase of Bakken crude poses another challenge to the nation: spills from oil-hauling trains. There are few ways to move Bakken crude from wells in North Dakota to refiners and consumers across the country. To keep up with the demand, producers have turned to rail transport as a quick alternative. In 2010, rail moved less than five million tons of crude petroleum. By 2013, that number had jumped to nearly 40 million.

NOAA typically responds to marine spills, but our scientific experience also proves useful when oil spills into a navigable river, as can happen when a train derails. To help answer response questions for waterways at risk, we’re adding even more data to our tools for spill responders. Ongoing updates to the Environmental Response Management Application (ERMA), our online mapping tool for environmental response data, illustrate the intersection of railroads and sensitive habitats and species, which might be affected by a spill from a train carrying oil.

Our Neighbor to the North

Oil imports from Canada, where oil sands (also known as tar sands) account for almost all of the country’s oil, have surged. Since 2010 Canadian oil imports have increased more than 40 percent.

Oil sands present another set of unique challenges. This variety is a thick, heavy crude oil (bitumen), which has to be diluted with a thinner type of oil to allow it to flow through a pipeline for transport. The resulting product is known as diluted bitumen, or dilbit.

Because oil sands are a mixture of products, it’s not completely clear how they react in the environment. When this product is released into water, the oils can separate quickly between lighter and heavier parts. As such, responders might have to worry about both lighter components vaporizing into toxic fumes in the air and heavier oil components potentially sinking down into the water column or bottom sediments, becoming more difficult to clean up. This also means that bottom-dwelling organisms may be more vulnerable to spills of oil sands than other types of oils.

As our experts work to assess the impacts from oil sands spills (including the 2010 Enbridge pipeline spill in Michigan), their studies both inform restoration for past spills and help guide response for the next spill. We’ve been working with the response and restoration community around the country to incorporate these lessons into spill response, including at recent meetings of the West Coast Joint Assessment Team and the International Spill Control Organization.

Even Further North

As shrinking summer sea ice opens shipping routes and opportunities for oil and gas production in the Arctic, the risk of an oil spill increases for that region. By 2020, up to 40 million tons per year of oil and gas are expected to travel the Northern Sea route through the Arctic Ocean.

Responding to oil spills in the Arctic will not be easy. Weather can be harsh, even in August. Logistical support is limited, and so is baseline science. Yet in the last five years, NOAA’s Office of Response and Restoration has made leaps in Arctic preparedness. For example, since 2010, we launched Arctic ERMA, a version of our interactive response data mapping tool customized for the region, and released Arctic Ephemeral Data Guidelines, a series of guidelines for collecting high-priority, time-sensitive data in the Arctic after an oil spill. But we still have plenty of work ahead of us.

Ship breaking ice in Arctic waters.

The U.S. Coast Guard Cutter Healy breaks ice in Arctic waters. A ship like this would be the likely center of operations for an oil spill in this remote and harsh region. (NOAA)

During a spill, we predict where oil is going, but Arctic conditions change the way oil behaves compared with warmer waters. Cold temperatures make oil more viscous (thick and slow-flowing), and in a spill, oil may be trapped in, on, and under floating sea ice, further complicating predictions of its movement.

We’ve been working to overcome this challenge by improving our models of oil movement and weathering in icy waters and researching response techniques and oil behavior to close gaps in the science. This May, we also find ourselves in a new role as the United States takes chairmanship of the Arctic Council. Amy Merten of NOAA’s Office of Response and Restoration will chair the Arctic Council’s Emergency Prevention, Preparedness and Response Working Group, where we hope to continue international efforts to boost Arctic spill preparedness.

Expecting the Unexpected

After decades of dealing with oil spills, we know one thing for certain—we have to be ready for anything.

In the last five years, we’ve responded to spills from the mangroves of Bangladesh to the banks of the Ohio River. These spills have involved Bakken crude, oil sands, and hazardous chemicals. They have resulted from well blowouts, leaking pipelines, derailed trains, grounded ships, storms, and more. In fact, one of the largest spills we’ve responded to since Deepwater Horizon involved 224,000 gallons of molasses released into a Hawaiian harbor.

Whatever the situation, it’s our job to provide the best available science for decisions. NOAA has more than 25 years of experience responding to oil spills. Over that time, we have continued to fine-tune our scientific understanding to better protect our coasts from this kind of pollution, a commitment that extends to whatever the next challenge may bring.


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What Have We Learned About Using Dispersants During the Next Big Oil Spill?

The Deepwater Horizon Oil Spill: Five Years Later

This is the eighth in a series of stories over the coming weeks looking at various topics related to the response, the Natural Resource Damage Assessment science, restoration efforts, and the future of the Gulf of Mexico.

A U.S. Air Force plane drops an oil-dispersing chemical onto an oil slick on the Gulf of Mexico

A U.S. Air Force plane drops an oil-dispersing chemical onto an oil slick on the Gulf of Mexico May 5, 2010, as part of the Deepwater Horizon response effort. (NOAA)

Five years ago, in the middle of the response to the Deepwater Horizon oil spill, I was thrown into a scientific debate about the role of chemical dispersants in response to the spill. Dispersants are one of those things that are talked about a lot in the context of oil spills, but in reality used pretty rarely. Over my more than 20 years in spill response, I’ve only been involved with a handful of oil spills that used dispersants.

But the unprecedented use of chemical dispersants on and below the ocean’s surface during the Deepwater Horizon oil spill raised all sorts of scientific, public, and political questions. Questions about both their effectiveness in minimizing impacts from oil as well as their potential consequences for marine life in the Gulf of Mexico.

Did we understand how the ingredients and components of the dispersants behave? How toxic are they? What are the potential risks of dispersants and do they outweigh the benefits?

We knew the flood of questions wouldn’t end when the gushing oil well was capped; they would only intensify the next time there was a significant oil spill in U.S. waters. NOAA, as the primary scientific adviser to the U.S. Coast Guard, would need to keep abreast of the surge of new information and be prepared to answer those questions. Five years later, we know a lot more, but many of the scientific, public, and policy questions remain open to debate.

What Are Dispersants?

Dispersants are a class of chemicals specifically designed to remove oil from the water surface. One commonly used brand name is Corexit, but there are dozens of different dispersant mixtures (see this list of all the products available for use during an oil spill).

They work by breaking up oil slicks into lots of small droplets, similar to how dish detergent breaks up the greasy mess on a lasagna pan. These tiny droplets have a high surface area-to-volume ratio, making them easier for oil-eating microbes to break them down (through the process of biodegradation). Their small size also makes the oil droplets less buoyant, allowing them to scatter throughout the water column more easily.

Why Does Getting Oil off the Ocean Surface Matter?

Oil slicks on the water surface are particularly dangerous to seabirds, sea turtles, marine mammals, sensitive early life stages of fish (e.g., fish eggs and embryos), and intertidal resources (such as marshes and beaches and all of the plants and animals that live in those habitats). Oil, in addition to being toxic when inhaled or ingested, interferes with birds’ and mammals’ ability to stay waterproof and maintain a normal body temperature, often resulting in death from hypothermia. Floating oil can drift long distances and then strand on shorelines, creating a bigger cleanup challenge.

However, applying dispersants to an oil slick instead shifts the possibility of oil exposure to animals living in the water column beneath the ocean surface and on the sea floor. We talk about making a choice between either protecting shorelines and surface-dwelling animals or protecting organisms in the water column.

But during a large spill like the Deepwater Horizon, this is a false choice. No response technology is 100 percent effective, so it’s not either this or that; it’s how much of each? If responders do use dispersants, some oil will still remain on the surface (or reach the surface in the case of subsurface dispersants), and if they don’t use dispersants, some oil will still naturally mix into or remain in the water column.

Why Don’t We Just Clean up Oil with Booms and Skimmers?

Cleaning up oil with mechanical response methods like skimmers is preferable because these vessels actually remove the mess from the environment by skimming and collecting oil off the water surface. And in most spills, that is all we use. There are thousands of small and medium-sized spills annually, and mechanical cleanup is the norm for these incidents.

But these methods, known as “mechanical recovery,” can only remove some of the oil. Under ideal (rather than normal) circumstances, skimmers can recover—at best—only around 40 percent of an oil spill. During the Deepwater Horizon oil spill response, skimmers only managed to recover approximately 3 percent of the oil released.

Dispersants generally are only considered when mechanical cleanup would be swamped or is considered infeasible. During a big spill, mechanical recovery may only account for a small percentage of the oil. Booms (long floating barriers used to contain or soak up oil) and skimmers don’t work well in rough seas and take more time to deploy. Booms also require constant maintenance or they can become moved around by wind and waves away from their targeted areas. If they get washed onto shore, booms can cause significant damage, particularly in sensitive areas such as marshes and wetlands.

Aircraft spraying dispersant are able to treat huge areas of water quickly while a skimmer moves very slowly, only one to two miles per hour. In the open ocean spilled oil can spread as fast, or faster, than the equipment trying to corral it.

Isn’t There Something Better?

Chemical product label for Corexit dispersant.

Dispersants, such as Corexit, are a class of chemicals specifically designed to remove oil from the water surface by breaking up oil slicks into lots of small droplets. (NOAA)

Well, researchers are trying to develop more effective response tools, including safer dispersants. And the questions surrounding the potential benefits and risks of using dispersants in the Gulf of Mexico have led to substantial research in the Gulf and other waters at risk from spills, including the Arctic. That research is ongoing, and answering one question usually leads to several more.

Unfortunately, however, once an oil spill occurs, we don’t have the luxury of waiting for more research to address lingering scientific and technical concerns. A decision will have to be made quickly and with incomplete information, applied to the situation at the moment. And if, during a large spill, mechanical methods become overwhelmed, the question may be: Is doing nothing else better than using dispersants?

That summer of 2010, in between trips to the Gulf and to hearings in DC, we began to evaluate the observations and science conducted during the spill to build a foundation for planning and decision making in future spills. In 2011, NOAA and our partners held a national workshop of federal, state, industry, and academic scientists to discuss what was known about dispersants and considerations for their use in future spills. You can read the reports and background materials from that workshop.

That was not the only symposium focused on dispersant science and knowledge. Almost every major marine science conference over the past five years has devoted time to the issue. I’ve been involved in workshops and conferences from Florida to Alaska, all wrestling with this issue.

What Have We Learned?

Freshly spilled crude oil in the Ohmsett saltwater test tank starts turning brown after dispersants applied.

The Deepwater Horizon oil spill spawned a larger interest in researching dispersants. Here, you can see freshly spilled crude oil in the Ohmsett saltwater test tank in New Jersey, where the oil starts changing a few minutes after dispersants were applied. Note that some of the oil is still black, but some is turning brown. (NOAA)

Now, five years later, many questions remain and more research is coming out almost daily, including possible impacts from these chemicals on humans—both those active in the response as well as residents near the sites of oiling. Keeping up with this research is a major challenge, but we are working closely with our state and federal partners, including the U.S. Environmental Protection Agency and Coast Guard, as well as those in the academic community to digest the flow of information.

The biggest lesson learned is one we already knew. Once oil is spilled there are no good outcomes and every response technology involves trade-offs.

Dispersants don’t remove oil from the environment, but they do help reduce the concentration of the oil by spreading it out in the water (which ocean currents and other processes do naturally), while also increasing degradation rates of oil. They reduce the amount of floating oil, which reduces the risk for some organisms and environments, but increases the risk for others. We also know that some marine species are even more sensitive to oil than we previously thought, especially for some developmental stages of offshore fish including tuna and mahi mahi.

But we also know, from the Exxon Valdez and other spills, that oil on the shore can persist for decades and create a chronic source of oil exposure for birds, mammals, fish, and shellfish that live near shore. We don’t want oil in the water column, and we don’t want oil in our bays and shorelines. Basically, we don’t want oil spills at all. That sounds like something everyone can agree with.

But until we stop using, storing and transporting oil, we have the risk of spills. The decision to use dispersants or not use dispersants will never be clear cut. Nor will it be done without a lot of discussion of the trade-offs. The many real and heart-felt concerns about potential consequences aren’t dismissed lightly by the responders who have to make tough choices during a spill.

I am reminded of President Harry Truman who reportedly said he wanted a one-handed economist, since his economic advisers would always say, “on the one hand…on the other.”


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After an Oil Spill, How—and Why—Do We Survey Affected Shorelines?

Four people walking along a beach.

A team of responders surveying the shoreline of Raccoon Island, Louisiana, on May 12, 2010. They use a systematic method for surveying and describing shorelines affected by oil spills, which was developed during the Exxon Valdez spill in 1989. (U.S. Navy)

This is part of the National Ocean Service’s efforts to celebrate our role in the surveys that inform our lives and protect our coasts.

In March of 1989, oil spill responders in Valdez, Alaska, had a problem. They had a very large oil spill on their hands after the tanker Exxon Valdez had run aground on Bligh Reef in Prince William Sound.

At the time, many aspects of the situation were unprecedented—including the amount of oil spilled and the level of response and cleanup required. Further complicating their efforts were the miles and miles of remote shoreline along Prince William Sound. How could responders know which shorelines were hardest hit by the oil and where they should focus their cleanup efforts? Plus, with so many people involved in the response, what one person might consider “light oiling” on a particular beach, another might consider “heavy oiling.” They needed a systematic way to document the oil spill’s impacts on the extensive shorelines of the sound.

Out of these needs ultimately came the Shoreline Cleanup and Assessment Technique, or SCAT. NOAA was a key player involved in developing this formal process for surveying coastal shorelines affected by oil spills. Today, we maintain the only SCAT program in the federal government although we have been working with the U.S. Environmental Protection Agency (EPA) to help develop similar methods for oil spills on inland lakes and rivers.

Survey Says …

SCAT aims to describe both the oil and the environment along discrete stretches of shoreline potentially affected by an oil spill. Based on that information, responders then can determine the appropriate cleanup methods that will do the most good and the least harm for each section of shoreline.

The teams of trained responders performing SCAT surveys normally are composed of representatives from the state and federal government and the organization responsible for the spill. They head out into the field, armed with SCAT’s clear methodology for categorizing the level and kind of oiling on the shoreline. This includes standardized definitions for describing how thick the oil is, its level of weathering (physical or chemical change), and the type of shoreline impacted, which may be as different as a rocky shoreline, a saltwater marsh, or flooded low-lying tundra.

After carefully documenting these data along all possibly affected portions of shoreline, the teams make their recommendations for cleanup methods. In the process, they have to take a number of other factors into account, such as whether threatened or endangered species are present or if the shoreline is in a high public access area.

It is actually very easy to do more damage than good when cleaning up oiled shorelines. The cleanup itself—with lots of people, heavy equipment, and activity—can be just as or even more harmful to the environment than spilled oil. For sensitive areas, such as a marsh, taking no cleanup action is often the best option for protecting the stability of the fragile shoreline, even if some oil remains.

Data, Data Everywhere

Having a common language for describing shoreline oiling is a critical piece of the conversation during a spill response. Without this standard protocol, spill responders would be reinventing the wheel for each spill. Along that same vein, responders at NOAA are working with the U.S. EPA and State of California to establish a common data standard for the mounds of data collected during these shoreline surveys.

Managing all of that data and turning it into useful products for the response is a lot of work. During bigger spills, multiple data specialists work around the clock to process the data collected during SCAT surveys, perform quality assurance and control, and create informational products, such as maps showing where oil is located and its level of coverage on various types of shorelines.

Data management tools such as GPS trackers and georeferenced photographs help speed up that process, but the next step is moving from paper forms used by SCAT field teams to electronic tools that enable these teams to directly enter their data into the central database for that spill.

Our goal is to create a data framework that can be translated into any tool for any handheld electronic device. These guidelines would provide consistency across digital platforms, specifying exactly what data are being collected and in which structure and format. Furthermore, they would standardize which data are being shared into a spill’s central database, whether they come from a state government agency or the company that caused the spill. This effort feeds into the larger picture for managing data during oil spills and allows everyone working on that spill to understand, access, and work with the data collected, for a long time after the spill.

Currently, we are drafting these data standards for SCAT surveys and incorporating feedback from NOAA, EPA, and California. In the next year or two, we hope to offer these standards as official NOAA guidelines for gathering digital data during oiled shoreline surveys.

To learn more about how teams perform SCAT surveys, check out NOAA’s Shoreline Assessment Manual and Job Aid.


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Three and a Half Things You Didn’t Know About the History of Oil Spills

Lakeview oil gusher surrounded by sandbags.

The largest oil spill in the United States actually took place in 1910 in Kern county, California. The Lakeview #1 gusher is seen here, bordered by sandbags and derrick removed, after the well’s release had started to subside. (U.S. Geological Survey)

Like human-caused climate change and garbage in the ocean, oil spills seem to be another environmental plague of modern times. Or are they?

The human relationship with oil may be older than you think. In California’s San Joaquin Valley, that relationship may date back more than 13,000 years. Archaeologists have discovered a long history of Native Americans using oil from the area’s natural seeps, including the Yokut Indians creating dice-like game pieces out of walnut shells, asphalt, and abalone shells. At an archaeological site in Syria, the timeline extends back even further: bitumen oil was used to affix handles onto Middle Paleolithic flint tools dating to around 40,000 BC.

As history has a tendency to repeat itself, we can benefit from occasional glimpses back in time to place what is happening today into a context beyond our own fast-moving lives. When it comes to oil spills, you may be surprised to learn that this history goes far beyond—and is much more complicated than—simply the 2010 Deepwater Horizon and 1989 Exxon Valdez oil spills.

Based on the research of NOAA oil spill biologist Gary Shigenaka, here we present three and a half things you probably didn’t know about the history of oil spills.

1. Oil spills have been happening for more than 150 years, but society has only recently started considering them “disasters.”

If you look back in time for historical accounts of oil spills, you may have a hard time finding early reports. When the first oil prospectors in Pennsylvania would hit oil and it almost inevitably gushed into the nearby soil and streams, people at the time saw this not as “environmental degradation” but as a natural consequence of the good fortune of finding oil. In an 1866 account of Pennsylvania’s oil-producing Venango County, this attitude of acceptance becomes apparent:

When the first wells were opened…there was little or no tankage ready to receive it, and the oil ran into the creek and flooded the land around the wells until it lay in small ponds.  Pits were dug in the ground to receive it, and dams constructed to secure it, yet withal the loss was very great…the river was flooded with oil, and hundreds of barrels were gathered from the surface as low down as Franklin, and prepared as lubricating oil.  Even below this point oil could be gathered in the eddies and still water along the shore, and was distinctly perceptible as far down as Pittsburgh, one hundred and forty miles below.

2. The largest oil spill in the United States didn’t take place in the Gulf of Mexico in 2010 but in the California desert a hundred years earlier.

But similar to the Deepwater Horizon, this oil spill also stemmed from a runaway oil well. In Maricopa, California, the people drilling Lakeview Well No. 1 lost control of the well, which would eventually spew approximately 378 million gallons of oil into the sandy soil around it. The spill lasted more than a year, from March 14, 1910 until September 10, 1911, and only ceased after the well collapsed on itself, leaving a crater in the desert surrounded by layers of oil the consistency of asphalt.

3. The Alaskan Arctic is not untouched by oil spills; the first one happened in 1944.

The Naval ship S.S. Jonathan Harrington surrounded by Arctic sea ice.

The Naval ship S.S. Jonathan Harrington surrounded by Arctic sea ice. This ship likely caused the first major oil spill in Alaskan Arctic waters in August 1944. (U.S. Navy)

NOAA and many others are doing a lot of planning in case of an oil spill in the Alaskan Arctic. But whatever may happen in the future, in August of 1944, Alaska Native Thomas P. Brower, Sr. witnessed what was likely the first oil spill in the Alaskan Arctic. The U.S. Navy cargo ship S.S. Jonathan Harrington grounded on a sandbar near Barrow, Alaska. To lighten the ship enough to get off the sandbar, the crew apparently chose to release some of the oil it was carrying. In a 1978 interview, Brower describes the scene and its impacts on Arctic wildlife:

About 25,000 gallons of oil were deliberately spilled into the Beaufort Sea…the oil formed a mass several inches thick on top of the water. Both sides of the barrier islands in that area…became covered with oil.  That first year, I saw a solid mass of oil six to ten inches thick surrounding the islands.

…I observed how seals and birds who swam in the water would be blinded and suffocated by contact with the oil.  It took approximately four years for the oil to finally disappear. I have observed that the bowhead whale normally migrates close to these islands in the fall migration … But I observed that for four years after that oil spill, the whales made a wide detour out to sea from these islands.

And because the last point refers more to oil than oil spills, we’re counting it as item three and a half:

3½. The oil industry probably saved the whales.

Cartoon of whales throwing a ball with banners.

On April 20, 1861, this cartoon appeared in an issue of Vanity Fair in the United Kingdom. It hails the “Grand ball given by the whales in honor of the discovery of the oil wells in Pennsylvania.” (Public Domain)

The drilling of the first oil well in Pennsylvania in 1859 touched off the modern oil industry in the United States and beyond—and likely saved the populations of whales, particularly sperm whales, being hunted to near-extinction for their own oil, which was used for lighting and lubrication. The resulting boom in producing kerosene from petroleum delivered what would eventually be a lethal blow to the whaling industry, much to the whales’ delight.


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What Does It Take to Clean up the Cleanup From an Oil Spill?

Bags of oiled waste on a beach next to a No Smoking sign.

Bags and bags of oiled waste on the beach of Prince William Sound, Alaska, following the Exxon Valdez oil spill in March 1989. (NOAA)

Imagine spilling a can of paint on your basement floor (note: I have done this more than once.). Luckily, you have some paper towels nearby, and maybe some rags or an old towel you can use to mop up the mess. When you’re finished, all of those items probably will end up in the garbage. Maybe along with some of the old clothes you had on.

You might not think much about the amount of waste you generated, but it was probably a lot more than the volume of paint you spilled—maybe even 10 times as much. That number is actually a rule of thumb for oil spill cleanup. The amount of waste generated is typically about 10 times the volume of oil spilled.

Our colleagues at the International Tanker Owners Pollution Federation (ITOPF) did a study on this very topic, looking at the oil-to-waste ratio for nearly 20 spills [PDF]. (A messy job, for sure.) ITOPF found that the general rule for estimating waste at oil spills still held true at about 10 times the amount spilled.

The Mess of a Cleanup

Cleanup workers collect oily debris in bags on the banks of the Mississippi River.

Responders collect oily debris during the M/V Westchester oil spill in the Mississippi River near Empire, Louisiana, in November 2000. (NOAA)

What kinds of wastes are we talking about? Well, there is the oil recovered itself. In many cases, this can be recycled. Then there are oily liquids. These are the result of skimming oil off of the water surface, which tends to recover a lot of water too, and this has to be processed before it can be properly disposed. Shoreline cleanup is even messier, due to the large amounts of oily sands and gravel, along with seaweed, driftwood, and other debris that can end up getting oiled and need to be removed from beaches.

Some response equipment such as hard containment booms can be cleaned and reused, but that cleaning generates oily wastes too. Then there are the many sorbent materials used to mop up oil; these sorbent pads and soft booms may not be reusable and would be sent to a landfill. Finally, don’t forget about the oil-contaminated protective clothing, plastic bags, and all of the domestic garbage generated by an army of cleanup workers at the site of a spill response.

Aiming for Less Mess

A large U.S. oil spill response will have an entire section of personnel devoted to waste management. Their job is to provide the necessary storage and waste processing facilities, figure out what can be recycled, what will need to be taken to a proper landfill or incineration facility, and how to get it all there. That includes ensuring everything is in compliance with the necessary shipping, tracking, and disposal paperwork.

The amount of waste generated is a serious matter, particularly because oil spills often can occur in remote areas. In far-off locales, proper handling and transport of wastes is often as big a challenge as cleaning up the oil. Dealing with oily wastes is even more difficult in the Arctic and remote Pacific Islands such as Samoa because of the lack of adequate landfill space. One of the common goals of a spill response is to minimize wastes and segregate materials as much as possible to reduce disposal costs.

In a 2008 article [PDF], the U.S. Coast Guard explores in more detail the various sources of waste during an oil spill response and includes suggestions for incentivizing waste reduction during a response.


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Why Are Seabirds so Vulnerable to Oil Spills?

Out of the squawking thousands of black and white birds crowding the cliff, a single male sidled up to the rocky edge. After arranging a few out-of-place feathers with his sleek beak, the bird plunged like a bullet into the ocean below. These penguin look-alikes (no relation) are Common Murres. Found along the U.S. coast from Alaska to California, this abundant species of seabird dives underwater, using its wings to pursue a seafood dinner, namely small fish.

During an oil spill, however, these classic characteristics of murres and other seabirds work to their disadvantage, upping the chance they will encounter oil—and in more ways than one. To understand why seabirds are so vulnerable to oil spills, let’s return to our lone male murre and a hypothetical oil spill near his colony in the Gulf of Alaska.

Preening in an Oil Sheen

After diving hundreds of feet beneath the cold waters of the North Pacific Ocean, the male murre pops back to the surface with a belly full of fish—and feathers laminated in oil. This bird has surfaced from his dinner dive into an oil slick, a common problem for diving birds during oil spills. His coat of feathers, once warm and waterproof, is now matted. The oil is breaking up his interlocking layer of feathers, usually maintained by the bird’s constant arranging and rearranging, known as preening.

With his sensitive skin suddenly exposed not just to the irritating influence of oil but also to the cold, the male murre becomes chilled. If he does not repair the alignment of his feathers soon, hypothermia could set in. This same insulating structure also traps air and helps the bird float on the water’s surface, but without it, the bird would struggle to stay afloat.

Quickly, the freshly oiled seabird begins preening. But with each peck of his pointed beak into the plumage, he gulps down small amounts of oil. If the murre ingests enough oil, it could have serious effects on his internal organs. Impacts range from disrupted digestion and diarrhea to liver and kidney damage and destruction of red blood cells (anemia).

But oil can find yet another way of entering the bird: via the lungs. When oil is spilled, it begins interacting with the wind, water, and waves and changing its physical and chemical properties through the process of weathering. Some components of the oil may evaporate, and the murre, bobbing on the water’s surface, could breathe in the resulting toxic fumes, leading to potential lung problems.

Birds’-Eye View

Colony of murres on a rocky outcropping on the California coast.

Murres are very social birds, living in large colonies on rocky cliffs and shores along the U.S. West Coast. If disturbed by an oil spill, many of these birds may set off temporarily to find a more suitable home. (Creative Commons: Donna Pomeroy, Attribution-NonCommercial 3.0 Unported License)

This single male murre is likely not the only one in his colony to experience a run-in with the oil spill. Even those seabirds not encountering the oil directly can be affected. With oil spread across areas where the birds normally search for food and with some of their prey potentially contaminated or killed by the oil, the colony may have to travel farther away to find enough to eat. On the other hand, large numbers of these seabirds may decide to up and move to another home for the time being.

At the same time that good food is becoming scarcer, these birds will need even more food to keep up their energy levels to stay warm, find food, and ward off disease. One source of stress—the oil spill—can exacerbate many other stresses that the birds often can handle under usual circumstances.

If the oil spill happens during mating and nesting time, the impacts can be even more severe. Reproducing requires a lot of energy, and on top of that, exposure to oil can hinder birds’ ability to reproduce. Eggs and very young birds are particularly sensitive to the toxic and potentially deadly properties of oil. Murres lay only one egg at a time, meaning they are slower to replace themselves.

The glossy-eyed male murre we are following, even if he manages to escape most of the immediate impacts of being oiled, would soon face the daunting responsibility of taking care of his fledgling chick. As young as three weeks old, his one, still-developing chick plops off the steep cliff face where the colony resides and tumbles into the ocean, perhaps a thousand feet to its waiting father below. There, the father murre is the chick’s constant caregiver as they travel out to sea, an energy-intensive role even without having to deal with the potential fallout from an oil spill.

Birds of a Feather Get Oiled Together

Like a bathtub filled with rubber ducks, murres form giant floating congregations on the water, known as “rafts,” which can include up to 250,000 birds. In fact, murres spend all but three or four months of the year out at sea. Depending on where the oil travels after a spill, a raft of murres could float right into it, a scenario which may be especially likely considering murre habitat often overlaps with major shipping channels.

After the 1989 Exxon Valdez oil spill in Prince William Sound, responders collected some 30,000 dead, oil-covered birds. Nearly three-quarters of them were murres, but the total included other birds which dive or feed on the ocean surface as well. Because most bird carcasses never make it to shore intact where researchers can count them, they have to make estimations of the total number of birds killed. The best approximation from the Exxon Valdez spill is that 250,000 birds died, with 185,000 of them murres.

While this population of seabirds certainly suffered from this oil spill (perhaps losing up to 40 percent of the population), murres began recovering within a few years of the Exxon Valdez oil spill. Surprisingly resilient, this species is nonetheless one of the most studied seabirds [PDF] precisely because it is so often the victim of oil spills.


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A Final Farewell to Oil Tankers with Single Hulls

January 1, 2015 marks a major milestone in preventing oil spills. That date is the deadline which the landmark Oil Pollution Act of 1990 (OPA-90) specifies for phasing out single-hull tankers in U.S. waters. That act, passed after the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska, required that all new tankers and tank-barges be built with double hulls.

Recently constructed single-hull tankers were allowed to operate, but 25 years after the Exxon Valdez, those vessels are now at the end of their operational life and will no longer be able to carry oil as cargo. The requirement was phased in gradually because of the difficultly of converting existing single-hull tankers to double hulls, and retiring the single-hull tankers more rapidly would have been a major disruption to world shipping.

Counting Down to a New Era

There won’t be a dramatic change-over on New Year’s Eve; most of the tankers calling on U.S. ports have had double hulls years before this deadline. However, one ship which was not switched over to a double hull soon enough was the tanker Athos I. This ship, carrying 13.6 million gallons of heavy crude oil, struck a submerged anchor in the Delaware River and caused a relatively large, complicated oil spill near Philadelphia, Pennsylvania, 10 year ago.

In 1992, two years after the Oil Pollution Act, the International Convention for the Prevention of Pollution from Ships (the MARPOL Convention) was amended to require all newly built tankers have double hulls. MARPOL has been ratified by 150 countries, representing over 99 percent of merchant tonnage shipped worldwide.

Stay out of Trouble by Going Double

So, what is the big issue around single vs. double-hull ships? Historically, tankers carrying oil were built with a single hull, or single shell.

While we measure oil in barrels, it is not actually shipped that way. Instead, oil is pumped into huge tanks that are part of the structure of tankers and barges. For vessels with a single hull, one plate of steel is all that separates the oil on board from the ocean. If the hull were punctured from a collision or grounding, an oil spill is pretty much guaranteed to follow. On the other hand, a ship with a double hull has two plates of steel with empty space in between them. The second hull creates a buffer zone between the ocean and the cargo of oil.

Naval architects have debated the merits of various hull designs in reducing oil spills, and using a double hull, essentially a hull within a hull, was selected as the preferred vessel design.

Close up of gash in hull on Cosco Busan cargo ship.

The cargo ship Cosco Busan lost 53,000 gallons of fuel oil when the single-hull ship hit the San Francisco-Oakland Bay Bridge in 2007. (U.S. Coast Guard)

However, the double hull requirements only apply to tankers and tank barges. Container ships, freighters, cruise ships, and other types of vessels are still built with single hulls. While these ships carry a lot less oil than a tanker, a large non-tank vessel can still carry a lot of fuel oil, and some have caused some pretty big spills, including the 2007 oil spill caused by the cargo ship Cosco Busan in San Francisco Bay.

Of course, double hulls don’t prevent all oil spills from tankers either, but the design has been credited with reducing the amount spilled, especially in the cases of low-speed groundings and collisions.

And some pretty spectacular collisions have resulted in double-hull tankers not spilling a drop.

Twenty years after the Exxon Valdez oil spill, the Norwegian tanker SKS Satilla collided with a submerged oil rig in the Gulf of Mexico. The collision tore a huge hole in the side of the oil tanker, but, thankfully, none of the 41 million gallons of crude oil it had on board was spilled.

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