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Cover Story

Buncefield oil depot incident

By Roy Wilsher

• Fight the fire
• Tactical plan
• Foam attack
• The site
• Other factors
• Early lessons

At 0602 hours on Sunday, December 11, 2005 Hertfordshire Fire and Rescue Service Control Center received the first of more than 60 calls to an incident at the Buncefield Oil Depot. Other surrounding control centers received another 150 calls. The officer-in-charge declared a “major incident” after just eight minutes of being on the scene.

The massive explosion at the oil depot was heard some 200 miles (322 kilometers) away. The blast blew windows out of homes 2 miles (3 kilometers) away and devastated the surrounding industrial area including the total or partial collapse of numerous commercial buildings, which during the working week would have been occupied by several thousand workers. Although 43 people were hurt in the explosion, no one was seriously injured or lost their life. The most seriously injured individual spent just over two days in the hospital recovering.

The initial crews were confronted with a scene of unprecedented destruction covering several square kilometers, which has been described as the largest incident of its kind in peacetime Europe. Aside from setting fire to the oil storage tanks and causing the devastation, the blast destroyed the oil depot control center, the emergency water supply pump houses, and completely obstructed perimeter roads. The intensity of the fires meant that two of the three emergency open-water supplies were inaccessible.

The pre-planning for this site followed national guidelines and focused on the largest single tank involved in fire, with foam concentrate, emergency water supplies, and foam making equipment stored on site for immediate use by local crews. Hertfordshire crews had trained at the site using this equipment on six occasions in the last six months. On arrival, fire fighters found 20 tanks ablaze and flames were leaping 200 feet (60 meters) into the air. The thick black plume of smoke created a gigantic cloud that was easily visible on satellite pictures. The plume initially moved in a southeasterly direction from the site.

At 0720, Deputy Chief Fire Officer Mark Yates went to the scene and following a briefing took command at 0747. Over the next five days, the five Hertfordshire Principal Officers rotated the command to ensure there was always one of them at both Gold Command and the incident.

Hertfordshire Resilience, which was first established as Hertfordshire Emergency Services Major Incident Committee (HESMIC) 30 years ago to facilitate multi-agency emergency planning, set up Gold Command at Hertfordshire Police’s headquarters.

I attended Gold Command within the first hour of the incident. The UK emergency services and partner agencies operate a Gold, Silver, and Bronze command structure. This equates to strategic or Gold (usually away from the incident), tactical of Silver (usually command units at the scene) and operational or Bronze (frontline fire fighting or rescue). The first Police Gold meeting was held at 0800 and the first multi-agency meeting was at 0900. Gold continued to meet until the night of Thursday, December 14.

Fight the fire
The incident had to be dealt within a number of phases. First, the Incident Commander called for search-and-rescue operations in the numerous collapsed and damaged buildings in the surrounding district. A three-story office complex adjacent to the oil depot was on fire because of the blast. This necessitated eight fire engines and one aerial appliance to stay on site while the search-and-rescue operations were being conducted. At this early stage, the oil depot was considered as one sector with numerous ancillary buildings having to be searched for casualties and then water-cooling curtains being set up to protect the tanks that were not involved in fire. It was not until four days later that all persons could be finally accounted for.

Gold Command immediately started discussing the health and environmental issues surrounding the fire, including smoke-plume modeling. At one stage, this computer-based technology suggested that the smoke plume would have reached the European mainland, including France, Belgium and Luxembourg, within 24 hours.

The amount of smoke contributed to the Gold Command discussing whether to attempt to extinguish the fire or allow burning down. Health advice to residents was to “go indoors, stay in and tune in to local radio and TV announcements.” The possible pollution health effects also led to the closure of 250 schools for 2 days.

This effect, the possibility that the fires could burn for up to 9 days, the effect on northern Europe and the image of the fire service not tackling a fire of this size led to the decision to actively fight the fire. Following this decision, Gold Command identified and ordered bulk foam concentrate supplies and high-volume pumps, as it was apparent that a fire of this nature was well beyond even the regional resources available. The high-volume pumps have been provided to Fire and Rescue Services via central government as part of the national resilience program.

These pumps can each move 1,750 gallons (7,955 liters) of water per minute through 6-inch (15-centimeter) hose over significant distances. In association with many industrial and fire service supplies, Angus Fire became the primary supplier of foam concentrate providing a continuous supply for over the next four days, at the early stages this being giving Police escorts from over 200 miles (322 kilometers) away. The incident ultimately used over 600,000 liters (158,503 gallons) of foam concentrate.

In the initial phase, the nearby M1 motorway was shut for 12 hours. It was reopened Sunday evening. Only Junction 8 remained closed. The M10 motorway was also closed in those early hours to act as a marshalling area for the many fire and rescue and other service vehicles that were gathering for a sustained attack on the fire. It became another central government strategic aim to open the M1 motorway completely for the start of the Christmas holidays and this was achieved by the morning of Saturday, December 17. Gold Command initiated an air exclusion zone, which was finally settled on 1-mile (1.6 kilometer) high by a mile (1.6 kilometer) across in each direction to protect air traffic and to exclude media helicopters. This exclusion zone had to be reinforced on the Friday morning when media helicopters started to move in close and affect the foam blankets being used to prevent re-ignition.

Tactical plan
The deputy led a team that included oil industry fire fighters, technical experts, site managers, Hertfordshire and other local authority fire officers. This team decided to tackle the fire in four phases.

Phase one of the operation involved tackling the rim fires and peripheral tanks, while continuing to provide a water curtain to protect the intact tanks. Three phases would progressively work through the tanks while ensuring maintenance of the previously laid foam blankets.

The attack moved tank-to-tank with the largest tank always the last full tank fire to be tackled. The plan also had to be flexible to deal with bund fires, some re-ignition, tank collapses, and the discovery of pressure fed fires once the tanks were extinguished.

The only available water was a small lake about 1.1 miles (1.8 kilometers) away, which needed a temporary road to be built to provide access and Hertfordshire’s rescue boat to position the pumps. Gold Command, via the interim national control center in West Yorkshire assembled 14 high-volume pumps and the road building and craning facilities required to get the pumps into place. The fire-fighting plan required 32,000 liters (8,000 gallons) of water and 1,200 liters (400 gallons) of foam concentrate per minute. Along with the extraordinary logistical requirements for fighting the fire came a request for extensive floodlighting.

Foam attack
The major foam attack started at 0822 hrs on Monday morning (December 12). During the early hours of December 13, fire-fighting efforts were hampered after a tank suffered structural failure – which posed a risk to other tanks adjacent to it. Fire fighters were immediately pulled back from the site for their own safety. However, they were soon back fire fighting. A further tank collapsed on the Monday afternoon, which meant the Incident Commander had to order another withdrawal. All but two tanks were extinguished by Tuesday evening but bund fires and one tank (912) were still burning. Tank 912 contained petroleum and a decision was taken to allow it to burn down under control whilst all bund fires were extinguished. The last fire was extinguished at lunchtime on Wednesday, December 14. The “stop” (no further additional resources required) was sent at 1936 hrs on December 14.

Throughout the operation, high-volume pumps were used to move water run-off around the site to ensure all contaminated water was kept on site to avoid any potential contamination of the chalk sub strata, which acted as a water collecting area for London drinking water supplies. This was a significant worry for Gold and the tactical fire fighting team. The Environment Agency had warned that if any large amounts of contaminated water, both fuel and foam contamination escaped from the site it could severely affect the drinking water supplies for North West London for up to three decades. The local area is a chalk aquifer, which collects water to bore holes to supply drinking water in the area. This required the fire fighting plan to be amended in order to keep contaminated water on site. The water treatment plant was used for this purpose; first water was pumped from the treatment area to unaffected low earth banks or “bunds” for containment. As run off collected in the treatment plant, it was pumped to other on-site bunds to be contained. In addition, some run off was cycled through the dirty side of the treatment plant to the clean side to be re-used in the cooling jets protecting those tanks not involved. The vast majority of water run-off was contained on site and was eventually tankered off via over 500 tanker journeys to a wastewater treatment plant off site.

The foam used to extinguish the fire was in the main Angus Fire FP70, although some foam was dispatched to the scene from other agencies that did not meet the UK Groundwater Regulations of 1998 and therefore meant some contamination to the water run-off. The requirement for foam concentrate was so great during the sustained attack it was impossible to continuously monitor the concentrate being used. Equipment such as a Williams Fire & Hazard Control 2x6 Big Gun, a mobile EV2 foam tender capable of producing 40 minutes of foam and Patriot 11 monitors were used to extinguish the fires. Fire fighters went on to prevent re-ignition and burn-back by covering the exposed fuel with a medium expansion foam blanket using Fire Bund Foam Pourers. As the fire was extinguished, explosive atmosphere detectors and intrinsically safe cordon control were introduced to minimize the possibility of further flammable atmosphere explosions.

Gold Command met every few hours and dealt with the strategic logistics of the fire fighting operation, all press enquiries from around the world, health and plume monitoring and the commencement of planning for the recovery phase. The blast had displaced 25,000 people from their places of work as well as requiring 2000 people to be placed in temporary accommodation.

The conditions for our personnel were very harsh as there was dense smoke and extreme heat. At this stage, the Service was trying to change crews every three hours.

Crews were on site throughout Christmas and New Year, overseeing the damping down process, making sure there were no re-ignitions and overseeing safe removal of water from the site. Fire fighters from Hertfordshire remained on site until January 5, 2006.

At the peak of the incident on Monday, December 12, 180 fire fighters were on the scene and over the initial three days, more than 80 percent of Hertfordshire’s fire fighters were on scene. It took more than 600,000 liters (158,503 gallons) of foam concentrate, 40,000,000 liters (10,566,882 gallons) of water and 30 kilometers (20 miles) of fire hose to deal with the incident.

For the first time in its history, Hertfordshire Fire and Rescue Service, requested national mobilization of assets in order to deal with this incident. In addition, for the first time the interim national command and control center, based in West Yorkshire, was formally used to coordinate and request resources from fire authorities.

I am immensely proud of all fire fighting staff and other agencies that cooperated magnificently to ensure an excellent resolution to this incident. There is no doubt that the local site pre-planning, tactical fire fighting planning and the availability of regional and national assets contributed to what I consider to be a superb outcome to one of the most demanding incidents in living memory.

A government enquiry held jointly by the Health and Safety Executive (HSE) and the Environment Agency has been started but calls for a full public enquiry have been declined. An initial progress report by the Major Incident Investigation Board on February 22, 2006 does not go into the causes of the explosion, but looks at the environmental impact.

The site
Hemel Hempstead lies about 15 miles (24 kilometers) to the northwest of London.

Buncefield Oil Storage Depot is the fifth largest in the UK and is strategically important fuel storage site operated by a number of companies. The depot receives petrol, aviation fuel, diesel, and other fuels by pipeline. It stores and then distributes these fuels by pipeline and road tanker to London and southeast England, including to Heathrow Airport. The UK Petroleum Industry Association (UKPIA) reports that, before the events of December 11, 2005, Buncefield handled 8 percent of overall UK oil supplies into the market, including 20 percent of supply to consumers in southeast England. The terminal acted as a main pipeline transit point to meet 40 percent of Heathrow airport’s demand for aviation fuel.

One effect of the fire was concern over petroleum shortages in the local area and beyond. Although there was sufficient storage capacity for cars and over-road vehicles, extra aviation fuel was diverted to the airports from other facilities. Distribution of petroleum was a significant problem, as more than 120 road tankers were on site at the time of the explosion and it became a central government strategic aim to have these tankers on the road as soon as possible. Tankers started to move off site by the Tuesday afternoon but each one had to have their structural stability and roadworthiness checked before being allowed back into the supply chain. Many had windshields and other windows plus other exterior equipment such as mirrors replaced while parked up along a road not far from the site.

After separation of the multi-fuel product entering the sites from the pipelines, the fuel is stored in tanks individually dedicated to specific product types. Product then leaves the sites either by road tanker or, in the case of aviation jet fuel, via two dedicated 6-inch (15-centimeter) and 8-inch (20-centimeter) pipelines from the BPA site into the West London Walton Gatwick pipeline system. Fuel leaving the site by road is loaded by dedicated vehicle loading facilities at HOSL West, BP, and to a lesser extent BPA. There are also fire-fighting facilities on site, some of which are shared. The site water treatment is operated by BPA, collecting run-off water from the whole site into a water treatment plant in the northeast corner of the Depot.

Other factors
The Maylands industrial area is immediately adjacent to the Buncefield site and has over 600 businesses located there employing over 16,000 people. Eighty-eight businesses were severely damaged by the incident and it is estimated that between 4,000 and 5,000 jobs have been affected. The burden carried by business so far has been substantial in terms of additional costs and reduced turnover. On-going building safety assessments and restricted access have affected the re-establishment of normal business which has left many companies non operational or semi-operational.

Of the 88 worst affected businesses, many had their buildings and contents destroyed. Often, even if equipment and stock are relatively unaffected, restricted access has delayed the return to normal operation. To help deal with this aspect of the incident a Recovery Group was set up by December 12 and has been meeting regularly since December 13. This group has provided a strategic overview and immediate support to businesses and employees. The larger companies such as Fuji Film, 3 Com, and Northgate are deciding whether to stay in the local area or re-locate.

Early lessons

• Self-Mobilizing – Some Fire and Rescue Services mobilized people and equipment to the incident without being requested by Hertfordshire. One service sent a significant resource that established itself outside the Hertfordshire command structure. There was even one team that flew in from a Northern European country. This practice must cease.
• Environment – Protection of the environment is a significant issue in the modern world particular with an incident of this size. Often it will need to be a balance between airborne and ground pollution.
• Housing – Ensuring the welfare of firefighters and officers attending large incidents is common place but for the first time a significant number of firefighters from around the country needed temporary housing arrangements.
• Briefings from Satelite TV – National agencies should not take briefings from TV coverage but talk to the Commander on the ground who knows the facts.
• Media – Good working relationships with the media are paramount. They need a story, it is their job. Better to give them access to press conferences and pictures in order to broadcast the truth. A pool of reporters was allowed very close to the site on Monday to share images with all the press agencies.
• Agency Work Hours - This incident spread across the Christmas period and agencies other than the emergency services had few if any staff dealing with the aftermath, contaminated water and exposed fuel products during the immediate holiday period.
• Air Exclusion – consider the implementation and contiunued maintenance.
• Empower Attendees – Attendees should attend Gold, Silver and Brionze meetings empowered to make decisions and priorities.
• “Curved Balls” – Be ready for the unexpected, water run-off concerns, collapsed tanks, helicopters affecting foam blankets, adverse media coverage, welfare of firefighters etc.

Roy Wilsher is the Chief Fire Officer for the Hertfordshire Fire and Rescue Service.