By Tim Culmer
Planning an oil spill response is a complex and multifaceted issue. Everything about the response strategy including what teams should be deployed, what mitigation or control methods are used, and what tools are leveraged as support are often determined on a case-by-case basis.
Determining and implementing the most appropriate response can help protect the surrounding environment, mitigate damage to the ecosystem and wildlife, safeguard local economies, and much more. However, the resources and capabilities available to different responder groups can often vary dramatically.
Incident modelling tools can help navigate this challenge and establish more effective outcomes based on the resources available and the characteristics of the incident. They are a powerful support tool, providing situational awareness and decision support to aid the creation of more targeted responses.
In this article we explore the four key areas that need to be explored before a response begins, and how incident modelling tools such as Riskaware’s MarineAware can help make more informed decisions.
1. Who should respond to an oil spill?
There are various different players who may be involved in oil spill response and the primary responder will vary internationally and between incidents. Often who is involved is determined by size, location, and significance. For example, local authorities and emergency services may take the lead on a smaller spill, major spills may require state or national government intervention. Many spills will have several parties involved in the response.
Here are the key players who may be involved in a response:
- The offending vessel: From a legal perspective, the ship/organisation that caused the spill is liable to clear it or pay for response actions. These companies may have a disaster response strategy in place.
- Private companies: Organisations that cause the spill may hire outside resources to perform the response and/or clean-up.
- Coast guards: Some coastguards may have the resources to effectively respond to an oil spill, and others may need to involve other organisations. International coastguards may also get involved in a large-scale spill.
- Military: In large-scale events the military or navy may provide assistance. For example, during the Mauritius oil spill the French Navy got involved.
- Local communities: In many instances, local people may volunteer for clean-up or containment activities.
- NGOs: Outside experts, such as incident modelling teams like Riskaware, may be consulted about significant or complex events to help better understand the situation and help inform key deployment decisions.
2. Which oil spill response method is most appropriate?
There are many different options available to responders when dealing with an oil spill, each with different functions, optimal use cases and deployment scenarios. Responders need to evaluate the situation and determine which method will work most effectively given the parameters of the incident at hand.
Removing the oil from the ship
In some cases where a ship is at risk of leaking oil, it’s possible to remove the oil from the ship using pumps or move it to safety in order to prevent any oil spillage into the water or reduce the amount spilled. Any degradation or damage to a vessel reduces the likelihood of success for this method.
Containing the oil at the point of release
Oil booms can be deployed around a ship to contain the spill, or across rivers mouths and coastlines to protect these environments. Volatile sea and weather conditions significantly reduce the effectiveness of this method as they can cause oil to escape the booms or the booms to collapse. Absorbent booms may also be used to soak up the oil.
Dispersants cause oil to sink to the seabed where it would naturally break up over time. This method can be toxic to marine life so is best suited to deeper open water to avoid damage.
In situ burning
In combination with booms, responders may contain the oil spill and then perform controlled burning to remove the oil.
Skimmers can be deployed to skim the oil off the surface of the water and then pump it into bladders to remove it.
3. How will external factors impact our response?
The nature or state of the incident and the surrounding area will have significant influence over how responders choose to proceed. There are various critical factors which authorities and/or organisations in charge will evaluate before finalising their response plan:
- Resources – What resources and capabilities are available, from booms, ships, and aircraft to manpower.
- Sea State – What the weather conditions in the area are and how this may impact the effectiveness of certain response methods. For example, booms won’t be as effective in high seas.
- Oil Type and Behaviour – Where, how, and how fast the oil is spreading and other behaviours, such as whether it is breaking up. In particular, new low sulphur oils are presenting novel challenges to the response community as they have variable and different properties to traditional fuels.
- Location – Where the oil spill is located; how far it is from response teams, how close it is to the coast, and how long it will take to travel to critical areas.
- Environment – Whether there are any sensitive or ecologically significant areas nearby may affect deployment strategies, such as marine reserves or coral reefs.
- Geography – The layout of the area and whether there are any natural characteristics which can help maximise the effectiveness of resources. For example, blocking the mouth of a river requires a minimal amount of resource but protects the entire river.
4. How do we prioritise our response?
Depending on the severity of the spill and the size of the slick, responders likely won’t be able to respond to the entire spill area. Although the most ideal scenario, and therefore the primary option, is always to try and contain the spill at sea, it’s equally necessary to assess whether this is possible. Ultimately, the reality may be that the oil will reach the coastline.
Responders will use all the above questions to assess the situation and the likely possible outcomes, and accordingly prioritise response actions in order to try and achieve the most optimal outcome.
What are the benefits of using oil spill modelling tools?
Incident modelling tools can help answer all the questions above using reliable data and provide essential context to uncertain situations. Tools, such as Riskaware’s MarineAware, can predict the oil’s trajectory and model when it is likely to reach critical environmental areas, as well as what the resulting impact may be.
This information helps organisations assess the severity of the situation, prioritise their resource deployment more appropriately and efficiently, and direct their mitigation or clean-up strategies in a targeted and timely manner. Guided by greater situational awareness, organisations can more effectively mitigate the risk to the surrounding environments, populations and economies. Reducing this impact and using resources more efficiently also has significant cost benefits.
These tools can be used throughout an evolving event or as an advance risk assessment readiness planning tool. In fact, many oil companies, for example, include oil spill modelling as a standard part of their Oil Pollution Emergency Plans (OPEPs), an inclusion which is now a legal requirement in the UK.