How Do You Clean Up an Oil Spill?

By: Josh Clark & Sarah Gleim  | 
oil spill off the coast of California
A long-billed curlew walks through oily water near a containment boom as a 3,000-barrel oil spill, about 126,000 gallons, from an offshore oil rig reaches the shore and sensitive wildlife habitats in Newport Beach, California, Oct. 3, 2021. DAVID MCNEW/AFP via Getty Images

Somewhere between Friday and Saturday, Oct. 1, and 2, 2021, at least 126,000 gallons (572,807 liters) of heavy crude leaked into the waters off the coast of California near Huntington Beach. Boaters began reporting an oily sheen on the surface of the ocean to officials, who then alerted the operators of three offshore platforms and pipelines nearby. All three, which are owned by Amplify Energy Corp., were shut down by Sunday.

"This oil spill constitutes one of the most devastating situations that our community has dealt with in decades," Huntington Beach Mayor Kim Carr said during a news conference Sunday. The ocean and shoreline are closed indefinitely, from Seapoint to Santa Ana.


The clean up is being coordinated by the U.S. Coast Guard and the city of Huntington Beach, and includes about 6 miles (9.6 kilometers) along the beaches and wetlands, according to a press statement from Huntington Beach Police Department. But what does that even look like? How do you start to clean up such a massive oil spill?

First let's discuss a bit about crude oil. The world has consumed about 97.4 barrels of oil every day so far in 2021 [source: U.S. Energy Information Administration]. To put that in perspective, there are about 42 gallons (159 liters) in every barrel. In the United States, 90 percent of that oil travels throughout the country via pipeline — eventually. But oil also travels in the U.S. via train car, tanker trucks and massive tanker ships. And where there are pipelines and oil tankers, there are leaks and spills.

But because of stricter penalties and better designs, the number of oil spills has decreased since the oil shipping boom began in the 1960s. However, since the 1969 oil well blowout in Santa Barbara, California, the U.S. has still had at least 44 oil spills with more than 10,000 barrels (420,000 gallons) each. The largest was the 2010 Deepwater Horizon well in the Gulf of Mexico, which killed 11 workers and lasted for more than 87 days. The damaged well dumped 4 million barrels (134 million gallons) of oil into the Gulf, causing $8.8 billion in natural resource damages.

And who could forget the 1989 Exxon Valdez catastrophe? It opened the eyes of the American public to the problem of oil tanker spills. The Valdez ran aground in Prince William Sound in Alaska releasing 11 million gallons of crude oil. As a result, Americans saw countless dead and dying birds and aquatic mammals covered in oil.

Those images of oil-soaked and dead birds sparked the question, "how do you undertake the daunting task of cleaning up millions of gallons of oil?" Agencies responsible for cleaning up oil spills — like the Coast Guard, National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency — have some clever and relatively simple methods.

When an oil spill occurs, the oil forms a millimeter-thick slick that floats on the water. The oil eventually spreads out, thinning as it does, until it becomes a widespread sheen on the water. How fast a cleanup crew can reach a spill — along with other factors, like waves, currents and weather — determines what method a team uses to clean a spill.

oil spill
Environmental workers clean up the ecologically sensitive Talbert Marsh as a major oil spill washes ashore in Huntington Beach Sunday, Oct. 3, 2021.
Allen J. Schaben/Los Angeles Times via Getty Images

If a crew can reach a spill within an hour or two, it may choose containment and skimming to clean up the slick. Long, buoyant booms that float on the water and a skirt that hangs below the water can help contain the slick and keep the oil from spreading out. This can make it easier to skim oil from the surface, using boats that suck or scoop the oil from the water and into containment tanks.

Crews also might use sorbents — large sponges that absorb the oil from the water.

An oil spill reached relatively quickly and located away from towns is the easiest to clean up by one of these methods. But rarely do things work out so easily. Oil spills are generally very messy, hazardous and environmentally threatening. Spills often reach shorelines, have time to spread and affect wildlife. In these cases cleanup crews use other measures.


Other Oil Clean Up Methods

oil spill
Oil is washed up on Huntington State Beach after a 126,000-gallon oil spill from an offshore oil platform on Oct. 3, 2021, in Huntington Beach, California. The spill forced the closure of the popular Great Pacific Airshow with authorities urging people to avoid beaches in the vicinity. Mario Tama/Getty Images

The sun, wave action and weather all contribute to the breakdown of oil in water. Eventually, the oil will evaporate. Because of this, experts leave some oil spills alone. If the slick doesn't threaten wildlife, business or civilization, cleanup agencies may choose to let the natural processes handle it.

Oil always floats in salt water, and most of the time in fresh water. In fresh water, though, the heaviest crude oil may sink. Often, as it breaks down, oil will mix with water — along with particulate matter like sand — and become tar balls. These balls tend to harden on the outside and stay soft in the middle. Since they are separate and scattered, tar balls and other degraded forms of oil in the sea don't pose the same kind of environmental threat as concentrated oil slicks do.


Often, oil spills in tropical areas are handled with dispersants — chemicals that break down oil much more quickly than the elements can alone. Dispersants were used to help break down the oil slick during the Deepwater Horizon catastrophe, though studies after questioned both their effectiveness and their consequences on marine life.

However NOAA says it prefers to use "mechanical recovery" methods, including skimmers and booms, as they can remove the oil from the environment by skimming it from the surface. But these methods aren't 100 percent effective — under ideal (not normal) conditions, mechanical recovery can remove about 40 percent of an oil from a spill, at best. During the Deepwater Horizon, skimmers fell far below that number and removed just 3 percent of the oil spilled.

When a slick threatens to infiltrate coastal areas — or worse, an oil spill occurs near a coastal area like the one in Huntington Beach — the situation becomes even more dire. Cleaning the spill becomes trickier as well, and methods to deal with the oil must also be more delicate.

But spills on the shore are most likely to affect wildlife habitats. Damage to wildlife from the current spill in California is still unknown. "We're hoping we have minimal impact, but we're preparing for the worst," Christian Corbo, a lieutenant at the California Department of Fish and Wildlife, told The Washington Post.

The severity of any oil spill and its proximity to wildlife habitats affect the number of aquatic wildlife hurt or killed. Waterfowl and other animals like seals and otters can become covered in oil, which breaks down the water-resistant properties of the birds' feathers, as well as the insulation provided by sea mammals' fur. Animals can be poisoned by the oil they ingest while licking themselves clean [source: NOAA].

Oil cleanup agencies use floating dummies and balloons to scare wildlife away from spill areas, but it doesn't prevent animals from being affected. Experts have techniques to help minimize the mortality rate among animals that become polluted by oil, but rescuing birds and sea mammals like walruses and otters present challenges. If the oil gets on the beaches and stays there, other creatures, such as snails and clams, can also suffer.

oil spill bird
Veterinarian Duane Tom examines a sanderling, a small shore bird taken to the Huntington Beach Wetlands and Wildlife Care Center Oct. 4, 2021, due to the oil spill.
Mindy Schauer/MediaNews Group/Orange County Register via Getty Images


Frequently Answered Questions

How the oil spills in oceans are cleared?
The most common method of cleaning up oil spills in oceans is using booms. Booms are long, floating barriers that are placed in the water to contain the oil and prevent it from spreading. Skimmers are then used to remove the oil from the water.

Lots More Information

Related HowStuffWorks Articles

  • Corn, Tony. "The revolution in Transatlantic affairs." Hoover Institution. August 2007.
  • Rogers, Paul and Ostrom, Mary Anne. "Clean up of huge oil spill begins." San Jose Mercury. Nov. 9, 2007.
  • Terdiman, Daniel. "Mixing high-tech into oil spill clean up efforts." CNet News. Nov. 20, 2007.
  • Basic petroleum statistics." U.S. Energy Information Administration. July 2007.
  • "How do you clean up an oil spill?" University of Delaware.
  • "Oil in the sea III." National Academies. 2002.
  • "Oil spill compendium data table: Number of spills by size." U.S. Coast Guard. September 2006.
  • "Oil spill clean-up agents threaten coral reefs." Science Daily. July 31, 2007.
  • "Oil spill clean-up volunteers suffer prolonged respiratory problems." Science Daily. Sept. 17, 2007.
  • "Rescuing wildlife." U.S. Environmental Protection Agency. March 9, 2006.
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