Buncefield Oil Depot Explosion and Its Environmental Impact

Introduction

On December 11 the year 2005, a great explosion occurred at the Buncefield Oil Depot. This is a major depot that stores and distributes fuel situated near Hemel Hempstead which is in the northwest direction of central London, 40 kilometers apart. Following the explosion that occurred, the fire was ignited and more than twenty tanks were involved. In this incident, an office building that was 100 meters away was as well set on fire. Some members of staff were also injured following this occurrence. There was also the destruction of the fire-water pumps and damage on offices on the site. Therefore, there was no capability in effectively fighting the fire from inside the site.

At the time the first day ended (Sunday 11), there had been success putting off the fire in the office block, and also there was a success in the prevention of the fire moving from the site to other tanks that were adjacent. On the day that followed, there was the setting up of a better plan to put off the fire. There was the application of huge amounts of foam to every tank and also on every bund to put off the fire. There was maintaining the blanket of foam to make sure there was no re-ignition.

By the fourth day, from the onset of this incident, it was only a single tank that was still on fire. On the fifth day, there was a declaration about the fire having been completely put off (Fire out). The investigation that followed this incident carried out by the Competent Authority showed that the original loss of primary containment was the overflowing of a petrol storage tank T912. This is among the three tanks in which HOSL operates. This went on for about thirty minutes and several tones of fuel overflowed bringing about a huge cloud of vapor. An explosion resulted from the ignition of this cloud of vapor that originated from some source.

At the start of the fire, there was a good performance of the bunds. The bunds were able to contain the firewater as well as the fuel that was leaking. This enabled the fire service to carry out the operations near the tanks that were burning and brought down the level at which the fire spread. But unfortunately, among the bund walls, some lost integrity in the days that followed and this caused the firewater that was contaminated as well as the fuel to find their way to other sites (Whitfield, & Nicholas, 2009).

Issues Raised By the Buncefield Oil Depot Explosion Incident Concerning Business Continuity Management (BCM), Security and Emergency Planning

Safe storing of liquid substances can be realized by carrying a combination of storage systems. These systems include the primary, secondary, and tertiary systems. In looking at the primary system, this is the most significant in evading major accidents that involve dangerous liquids. This is carried out by the storage vessels, pipework among other direct contact equipment with the liquid, and the management of control systems that are linked to it. This is also composed of a device that offers protection over primary containment loss. Such device includes high-level alarms that are connected to the shutdown systems.

Considering secondary containment, this one brings down the level of the negative effects that result from primary containment system failure. It does this by offering prevention to spreading the liquid that is dangerous that may be uncontrolled. This containment is achieved by equipment that is outside the primary containment system and is not dependent on it. This may include such equipment as clay bunds that are found around the storage tanks or clay. This containment will have also offer storage capacity which is limited for the management of firewater. The last containment system is the tertiary containment.

This containment brings down the level of negative effects in a situation where there is the failure of both secondary and primary containment systems. It achieves this by offering an extra barrier that enables prevention against the spreading of the dangerous liquid which is spread and not controlled. This containment is achieved by the utilization of means that are external to both primary and secondary containment. These may include diversion tanks, flexible booms, and site drainage (Whitfield, & Nicholas, 2009).

Thorough investigations were carried out by a joint investigation team on the Buncefield incident within one year. The team came from the Environmental Agency and HSE. The feature of the greatest significance was the explosion of the vapor cloud and it was this that brought about destruction on the off-site property (Whitfield, & Nicholas, 2009).

Thus the focus of those who investigated this incident was mostly directed towards the original loss of primary containment and on the system of the formation of the vapor cloud. Concerning the loss of both the tertiary and secondary containment findings included;

1. The bunds did not fall all through the incident and remained standing. However, they could not completely carry out the containing of the fuel and there was the loss of firewater.
2. The way the bund was designed did not make it possible to have firewater management that was effective. This was for the reason that no means were available to remove firewater safely from under foam and layer of fuel. A report came from the fire service that indicated that there was the eventual filling of the bunds and overflowing.
3. Most of the bund walls lost their containment at the pipework penetrations and leaking occurred because the seal in between the bund wall and pipes had been lost.
4. Product pipework that had been destroyed offered pathways for dangerous liquids to get out from the bunds or to move from bund to bund.
5. There was a variation in the way construction and expansion joints in the concrete slabs were performed from one bund to the other. Those joints that had good performance were having metal water stops. Those joints on which modification had been carried out by a metal plate installed in the internal face obtained some level of protection. In several bunds, the material that was found in the joints was greatly destroyed and this brought about integrity loss.
6. There was buckling and breaking of the concrete bund floor in two or more locations.
7. No fuel and water-fire were contained within the terminal boundaries by the tertiary containment systems. The main contribution to this was carried out by having inadequate drainage and also inadequate capacity and lagoon integrity as well as loss of power to pumps.
8. Even if the terminal was found on a clay layer that assisted in bringing down the level of the incident’s impact on the chalk aquifer that lay below, still there were a number of them located both on the site and off the site pathways that channeled dangerous materials that brought about pollution into the groundwater.

Solutions, Failures, and Lessons Learnt

Following this incident, in the course of this, the government engaged in setting up an investigation board (the Buncefield Major Incident Investigation Board – MIIB). The reports given out by this board have pointed out what caused the incident and have also given out recommendations on such issues as fuel storage sites operation as well as design. It has also given recommendations on other issues like “major incident emergency preparedness and work” concerning the explosion system (Anonymous, Final report published by the Buncefield investigation board, 2009).

This board has given out a recommendation that there is a need for a joint review of the current standards for tertiary as well as secondary containment systems by the Competent Authority to come up with guidance that is revised. In this review, there is a need to;

1. Come up with a specification of secondary minimum level performance.
2. Set up appropriate risk assessment means to offer priority for the engineering work program in responding to the newly set up specification.
3. Come up with specific standards in a formal way to be achieved for them to be insisted on in case there are no steps forward realized with the improvements.
4. Carrying out improvements on the management of firewater and also having improvements installed capability to transport the liquids that are contaminated to a location where they pose no threat to the environment in case the secondary containment is lost and also in the case of fires.
5. Offering assurance to a higher level of having measures of tertiary containment that protects against the liquids escaping from the site and posing a great threat to the environment.

More so, the solution to the prevention of future occurrence of such incidents could be prevented by applying standards that have been revised in totality to the newly set up sites. The revised standards could also be applied to all the major modifications that could be carried out on the current sites.

This is according to the recommendations made by the board (Buncefield Major Incident Investigation Board). The investigators made recognition that complete upgrading of the site drainage as well as bunding on the existing sites could not be practical. In a situation like this, those who carry out operations are supposed to come to an agreement with the Competent Authority concerning a plan based on risk for phased upgrading to realize the plant standards that are very much close to those of plant standards as possible most practically and reasonably (Whitfield, & Nicholas, 2009).

The Environment Agency, the oil industry, as well as HSE, jointly came up with BSTG (Buncefield Standards Task Group). This was for the purpose to carry out the coordination of the implementations of the lessons that were learned. The final report gives out recommendations regarding taking engineering measures to offer prevention to the secondary as well as tertiary containment loss. These engineering measures include;

• Bund integrity
• Fire-resistant bund joints
• Firewater management and risk assessment (Whitfield, & Nicholas, 2009).

Conclusion and Recommendations

Most of the fuel storage depots found in the United Kingdom were set up in the course of the 1950s and 1960s. Their design followed the environmental standards that were put in place concerning those days but from that time, there has been a rise in the containment standards. There must be keen consideration by all the companies in which dangerous liquids are stored of the incident that occurred in Buncefield for them to be able to see the possibility of losing the secondary and primary containment systems in the course of an incident.

It is very vital to be in a position to identify those pathways that the dangerous liquids may escape and take the appropriate measures to prevent this from coming about and have adverse effects. Even as the primary containment system is of very great importance, it has been indicated that both the secondary and tertiary containment systems play a great part in offering the last lines of protection.

Therefore, it is of great importance that the containment systems in the establishments like Buncefield undergo very keen review for the appropriate measures to be taken so that they meet the required standards (current standards). Taking these measures may be costly but comparing these costs with those that result from the occurrence of an incident like the one that occurred makes it very much necessary to take these measures.

Lessons must be learned from this incident that occurred in Buncefield and implements measures with the speed that will prevent the same from occurring in the future. It is now at a point where all the companies having dangerous liquids storage carefully assess the secondary as well as the tertiary containment they have in place to make sure that these systems are appropriate for proper functioning. Those establishments that do not have the secondary and tertiary containment rightly set up for the purpose for which they are meant are endangering the environment, people’s lives, property, and even their employment is at great risk.

Reference List

Anonymous, 2009. Final report published by the Buncefield investigation board. ENDS (Environmental Data Services), p. 24.

Whitfield, A., & Nicholas, M., 2009. Bunding at Buncefield: Successes, failures, and lessons learned. Loss Prevention Bulletin, (205), 19-25.