The explosion and subsequent fire at the fuel storage depot at Buncefield are familiar to most fire fighters; the issues linked to extinguishing the blaze are well versed and have been incorporated in to the training of many fire and rescue services across the UK, Europe and beyond. What is not as well-known are the ongoing effects that are still being felt today, 12 years after the blaze. These effects are environmental in nature and have the potential to cause significant human health issues.
The obvious environmental issue from Buncefield was the huge smoke plume which eventually made its way across the English Channel and gave this fire an international element. However, once the fire was out, the smoke dissipated and the associated air quality issues receded, there was still a lasting environmental issue, one which is still being felt today. During the operation to bring the fire under control, fire services from across the UK were asked to send any available foam stocks to the scene. The call for help was answered and large amounts of foam was sent to the scene, the problem was the type of foam which was sent. In 2005, when the fire took place, the UK fire services were well aware that there was to be a ban on the manufacture of PFOS containing substances which would come into force in 2009, with a ban on holding stock of PFOS containing products to come in to force in 2011. With that fact in mind, it was the PFOS containing foam which was sent to the fight the fire.
During the course of the fire, the containment bunds cracked and allowed fire water, contaminated with PFOS foam and fuel products to soak in to the underground water table. This Aquifer is an important public drinking water source for the Greater London area, but due to the contamination it is no longer available as a water supply and will remain unusable for several more years do the bio-accumulative nature of PFOS type chemicals.
Buncefield serves as a good example of why protecting the environment from firefighting activities is crucially important. It is all too easy for fire services to see environmental protection as a purely secondary role, but we are all reliant on the environment for food, water and air; we cannot remove ourselves from the environment and if it’s not healthy then the people who live in it won’t be healthy either.
Whilst Buncefield shows how persistent chemicals can be highly problematic in the environment it should not be assumed that only incidents that involve an identifiable chemical contaminant can present an environmental impact. All fire water runoff will be detrimental to the environment if it is allowed to enter a water course, regardless of any chemicals which may be involved in the fire or indeed any firefighting aides used to put the fire out faster. In 2012 when several thousand tonnes of waste wood caught fire at a site in Derbyshire the firefighting run off was so polluting it wiped out the aquatic life in several kilometres of the water course that received the runoff. This is due to the chemical processes that take place during combustion, they will result in an elevated biological and chemical oxygen demand which will in turn reduce the amount of available dissolved oxygen. Runoff is also likely to have a lower pH than the receiving watercourse adding another complication to what would traditionally be regarded as a fairly straightforward fire.
Whilst there are some remedial actions environmental response organisations (such as the Environment Agency in England) can use to mitigate the impacts of pollutants if they enter water courses, by far the best technique is to prevent pollution from entering in the first place.
The key to preventing the worst pollution is to have a response plan for sites which have a clear potential hazard should a fire take place on the site. In the UK these types of sites are governed by a range of different regulatory regimes (for example COMAH and IPPC) which require control measures to be in place to contain any runoff so it can be collected and disposed of in a safe way during the post incident work. Fire services should familiarise themselves with the on-site arrangements at any sites of this type in their response area. Many of the infrastructure requirements of the regulations will need some positive action to operate, such as drainage isolation valves or penstocks. These type of devices are identified on the sites response plan, which should describe the key site risks and the location of the site infrastructure which can help to contain pollution. In most cases (particularly in the case of COMAH sites) local fire services will be involved in the preplanning work and should have copies of the site response plans on station to help with preplanning the response.
For sites with this type of regulation, the risks are well managed and pre-identified, in addition to this, the regulations place controls on the site operator that greatly reduce the risk of an incident ever taking place. What is of more serious concern are the sites which fall below any regulatory requirement. For these types of site there could be a range of environmental hazards and crews may not have any idea of what they may be facing until they arrive at the scene. Preplanning in these cases may be difficult but there are some generic actions fire services can take which will help.
The pollution protection hierarchy
For sites which do not benefit from an on-site emergency response plan, a more generic approach is needed. The Environment Agency has developed a highly effective national partnership with the UK fire and rescue services which recognises both the environmental risks of fire service activities and the unique position the fire services are in to apply emergency environmental protection measures. The partnership sees the Environment Agency providing equipment and training for front line crews to deploy before the environment agency are even notified of an environmental incident.
For a pollution to occur, a substance must find its way in to the environment and eventually impact upon a receptor. It is possible to divide the stages of the pollution in to the following: Source, Pathway and Receptor.
The source, as the name suggests, is the point from which the pollutant is escaping from, it may be a leaking container such as an oil drum or IBC, a damaged bulk tanker involved in an RTC or failure of a tank or bund on an industrial site. The list of sources are incredibly varied but can be summarised as the point of failure where the substance becomes uncontained. The basic aim is to make the intervention as close to the source as possible. As the pollution spreads it will cause more contamination, resulting in increased hazards for responders and the public; and a more difficult and costly clean up.
Intervention at the source is critical and this requires a timely response, which is the fundamental reason the Environment Agency supplies the fire services with an environmental protection unit, (EPU) fully stocked with equipment specifically designed to quickly stop pollutions at source. This unit is in addition to the equipment the EA has provided for every front line firefighting appliance in the UK.
If it is not possible to make the intervention at the source of the pollution then the response must move back a stage to the pathway. The pathway is likely to comprise of several different elements, but a common scenario would be a leak from a ruptured tank which has flowed over land and entered a surface water drain which will allow the material to enter a nearby watercourse. The EPU is also stocked with a range of equipment which can effectively intervene and contain a spill before it makes it to the drainage system. Once contained, the contaminant can be disposed of safely or in the case of fire water runoff, be reused as firefighting water (providing the contamination will not damage equipment)
The most important pollution pathway is the drainage system, and where possible planning work should identify which type of drainage system is in use at any given site. Where this is not possible, an early call to the EA duty staff will assist incident commanders in identifying the best option for dealing with the pollution. It may be that the contamination can be diverted in to a foul water sewer for processing at a water treatment works, but checks will need to be made before this action is taken. The EA can act as a liaison point and establish the best course of action with the local utility providers.
Once the pollutant has moved through the pathway it will reach the receptor, in most cases this will be a watercourse or ground water. Depending on the physical properties of the pollutant, there may be some interventions that can still be made. For example if the pollutant floats on water then fence or absorbent booms are an option, if the pollutant has a high organic loading which will result in a crash of the dissolved oxygen levels, then aeration is an option. However, if the pollutant is toxic and soluble then the only option is to attempt to move down stream organisms out of the path of the pollutant. This is a capability which the EA can deliver in the form of electro fishing which uses an electrical current being used to temporarily stun fish so they can be netted out and moved to a safe location.
It’s clear that environmental considerations are important and should be factored in to any response which includes a release of chemicals or significant fire water runoff, and there are processes and structures in place to aid in the mitigation of the negative environmental impacts. Successful containment of pollution not only benefits the environment as a separate entity, but also protects all of us, as we rely on the environment for our water, food and the very air we breathe.
Where there are site specific plans in place, then local fire services should ensure their first responders are well versed and well-practiced on the contents of those plans. Where there is no specific plan, then responders should fall back on the more generic approach, by the application of the pollution protection hierarchy: Source, Pathway, Receptor. The Environment Agency are committed to supporting the fire services in training and exercising front line fire services in delivering environmental protection, and each local EA area has a dedicated fire service representative who supports the implementation of the national partnership at the local level, and ensures that the impacts of emergencies do not result in an environmental pollution which contaminated the food, water and air which we all need to survive.
For more information, go to www.environment-agency.gov.uk