At 13:43 on Friday 15 May 2009, a fuel tanker was unloading petrol into underground tanks at a suburban service station when a fire started at the fill point. The fire spread to the tyres of the tanker and later to its rear fuel compartments. Two of the rear compartments ruptured during the fire. One of the ruptures created a large fireball (about 60 m high and 20 m in diameter) that extensively damaged the petrol station building and associated infrastructure.
Fortunately, no-one was injured in the incident.
The fire was caused by the ignition of a mixture of fuel vapour and air close to the underground tank fill box. The source of the fuel vapour was probably within the containment sump, which was directly beneath the fill box. A definitive ignition source could not be identified.
During the early stages of the fire, the tanker driver did not use the fire extinguishers installed on the tanker nor those available at the petrol station. The fire spread from the fill point to the tanker. Use of the available fire extinguishers may have prevented the tanker from catching fire.
As a result of the investigation, recommendations to improve safety have been made in relation to the design and operation of underground petroleum storage systems and dangerous goods transport operations.
There is an urgent need to review the current practice of installing, for environmental protection, containment sumps beneath underground fuel tank fill boxes. This practice has had an unintended consequence — the accumulation of liquids (fuel–water mixture) in the sump can create a hazard that may be constantly present at the vapour recovery point if the sumps are not regularly checked and cleaned out. The petroleum industry should develop additional engineering controls to minimise this fire risk.
The petroleum industry should also review the design of existing fill boxes to ensure that minor leaks during fuel transfer operations are effectively contained within the fill box without the need to fit a containment sump.
Dangerous goods truck operators, particularly those carrying flammable liquids or flammable gases, should check the location of fire extinguishers on tanker vehicles to ensure their ready accessibility in an emergency. If it is impracticable for extinguishers to be more appropriately located, then procedures should be put in place to have a fire extinguisher alongside the driver while unloading fuel.