How are Oil Spills Cleaned up?

Many thousands of small oil spills occur each year. Oil spills can occur due to negligence, the breakdown of equipment, natural disasters or deliberate dumping. These spills can be devastating to the environment and wildlife surrounding the epicenter of the spill. Thankfully, oil molecules are hydrophobic, meaning they mostly float on the surface of the water, making cleanup by boats at least theoretically possible.

When oil spills occur, the oil initially remains concentrated, but begins to rapidly spread in all directions as time passes, producing an oil slick. If oil spills are caught early, the cleanup technique of burning in place, called in-situ burning, may be used. This is the most benign method of cleanup, but also one of the most rarely used methods because the oil must have a minimum thickness of 0.12 inches (3 mm) on the surface of the water in order to maintain a self-sustaining burn, and oil spills quickly spread out to thinner dimensions.

A boom, a type of corral which floats on the surface of the water, can be used to contain oil spills and artificially increase their thickness. Special fireproof booms are used in conjunction with in-situ burning. When in-situ burning is infeasible due to the thickness of the spill, booms are used to contain the oil so that skimmers — special boats with oil-absorbent plastics or vacuums — can be used.

When cleanup with booms or skimmers is impractical, chemical dispersants may be used. Chemical dispersants are used to break down stray oil and lessen its impact on beaches and aquatic wildlife.

Cleaning up large oil spills can be very expensive, tens or hundreds of millions of US dollars. Fines for spills are usually comparably severe. When an oil spill spreads out over a large area, it forms a sheen, a very thin rainbow-colored layer of oil on the surface of the water.

One of the largest oil spills in history was the Exxon Valdez oil spill in Prince William Sound in Alaska. Approximately 25% of the ship's 50 million gallons of oil was spilled, equivalent to approximately 125 Olympic-sized swimming pools, and roughly 250,000 birds died from the incident. The event caused the United States government to further increase the strictness of its fines and regulations meant to prevent against oil spills. Despite this, oil spills still occur; in 2010, an explosion on the Deepwater Horizon, a drilling rig in the Gulf of Mexico, lead to a spill of over 205 million gallons, according to scientific estimates.