During inland, inshore, or offshore oil spills, rapid response is critical to protect sensitive resources and the environment. Unfortunately, it can take hours or even days to reach a spill site and deploy the necessary equipment to stop the spill from growing any further and redirect it to a collection point. Keeping equipment such as oil spill containment booms readily available can oftentimes change the outcome of an oil spill significantly.
An oil spill containment boom is a floating barrier used to contain an oil spill on water. Containment booms usually consist of an above-water floating fence or “freeboard” designed to contain the oil and prevent waves from splashing over the boom, and a weighted skirt or “draft” to reduce the amount of oil lost underneath the boom. Couplings on at least one end are used to connect booms to one another, thereby allowing for unlimited overall boom length so that the spill can be completely contained.
What are the Different Types of Oil Spill Containment Booms?
Oil spill containment booms are available in a variety of shapes and sizes, each designed for specific applications. Most containment booms share the same design principles, including:
- a fence or freeboard above the waterline to prevent waves from splashing over the boom;
- an underwater skirt or draft to reduce the loss of oil under the boom;
- a means of flotation in the form of air, foam, or some other buoyant material;
- a longitudinal tension wire or chain to stabilize the boom against winds, waves, and current;
- a ballast to maintain vertical stability of the boom;
- couplings to connect each boom for unlimited length.
The two main categories of spill containment booms are fence booms and curtain booms.
Fence booms use a flat floatation device and a taller freeboard—the area between the waterline and the top of the boom. This flat design allows the boom to be deployed from and stored on large boom reels but they are less effective in rough waters, as wind and waves can cause the boom to act as a sail and twist.
Curtain booms use a circular floatation chamber filled with foam, air, or some other buoyant material. Like fence booms, curtain booms have a continuous skirt or “draft,” but perform better in rough waters because they’re able to float with the waves instead of fighting against them. Curtain booms, however, can be more difficult to store because they are not flat.
A lesser-known but still relevant oil spill containment boom is the shore-sealing boom, whereby the draft of the boom is replaced with water-filled chambers. This design allows the boom to rest on the exposed shoreline during low tide, thus protecting the beach from oil contamination.
The most common type of spill containment boom is called a “hard boom” and is non-absorbent; however, some oil spill containment booms are sorbent. Our own Ultra-Filter Boom, for example, is made of a special material that absorbs up to five gallons of oil per six-foot section, or more if deploying the skirted model, which absorbs oil underwater, as well as above. Connected sorbent booms are often used for skimming operations, where two boats pull the booms along to collect, not just contain, the oil.
Recently, a new style of containment boom has been developed that is far more portable than a traditional fence or curtain boom. This particular boom, the Ultra-Rapid Boom, folds flat and can be stored in a portable cartridge. It can be deployed in minutes by two non-specialized personnel and a single small boat. The unique geometry of this new style of containment boom has been successfully tested in seas up to six feet and wind speeds of up to 25 knots.
How Are Oil Spill Containment Booms Used?
Oil spill containment booms are not intended to clean up oil spills, even though some booms are sorbent and will help with the process. The role of a containment boom is to prevent the oil spill from expanding and/or diverting the oil to a collection point.
For larger oil spills, multiple containment booms may be connected end-to-end and towed by one or more vessels to encompass the oil slick. Fence booms, which have flat freeboards vs. rounded curtain booms, may be deployed using a large reel mounted to the vessel. In rare cases, booms may be anchored to mooring points, which can be pre-installed in case of a spill, as it is impracticable to lay multiple moorings in an emergency.
These operations can be slow and dangerous depending on tidal conditions, vessel maneuverability, the number of vessels required for the operation, how much boom each vessel can carry, and the simple fact that oil is a slippery, messy, substance. During catastrophic oil spills, volunteers will often assist with both initial containment and cleanup.
Are Oil Spill Containment Booms Effective?
When used properly, oil spill containment booms are not only effective but almost required in response to any significant oil spill. It is important, however, that the correct type of boom be used given the application. In fast-moving water environments, like intertidal areas and rivers, a high-tensile boom is necessary to be able to withstand waves and currents. In calmer waters, like streams and ditches, a lighter weight fence boom can be used.
Containment boom performance is something that should be observed, not assumed. For example, when oil is lost under a boom, it will appear as droplets rising from behind the boom. Booms can also twist, dip, or even sink under the waterline, causing oil to escape the containment area. This can occur for multiple reasons but is usually associated with tidal conditions, improper deployment, or simply the wrong type of boom given the application.
There has been plenty of controversy around the use of oil spill containment booms and their effectiveness. In particular, during some massive incidents where thousands of booms were used, not monitoring their use coupled with high seas resulted in the booms breaking free of one another, partially sinking, and even washing onshore.
As noted above, new containment boom technology is already preventing such mishaps, including with our own Ultra-Rapid Boom, which was tested for years in various conditions, and is still tested today.
Where Have Oil Spill Containment Booms Been Successfully Used?
Containment booms have been used in almost every significant oil spill. Most notable of late would be the Deepwater Horizon spill in 2010 in the Gulf of Mexico off of the coast of Louisiana. During that spill response, close to 800 miles of containment booms were deployed to corral the oil or to act as barriers to protect marshes, mangroves, fishing ranches, and other ecologically sensitive areas. Another 2,500+ miles of single-use sorbent booms were also deployed as both barriers and used in skimming operations.