Evidence as to the cause of the Hazelwood mine fire
The Board heard evidence about the cause of the fires within the Hazelwood mine from mine workers. Firefighting efforts are discussed in Chapter 2.3 Fighting the Hazelwood mine fire.
The Board also heard evidence from Mr Lapsley on the first day of the public hearings. In answering questions as to the cause of the fires in the mine, Mr Lapsley accepted that the fires could have been from spotting from the Hernes Oak fire or the Driffield fire.78 Mr Lapsley’s evidence was based on reports provided to him from mine personnel, personnel at the Energy Brix site and from members of the public who saw fires and smoke in the area.79
Supplementing the evidence of witnesses who directly observed the mine fire and from Mr Lapsley, the Board also heard evidence from Mr Jaymie Norris, Acting Manager, Stategic Bushfire Risk Assessment Unit at the Department of Environment and Primary Industries, about Phoenix Rapidfire modelling. Phoenix Rapidfire modelling is used to predict the spread of a fire and the occurrence of fire spotting. A more detailed discussion about Phoenix Rapidfire modelling is contained in Chapter 2.2 Preparing for fire.
Modelling provided the Board with additional guidance about the probability that embers spotting from each of the Hernes Oak and Driffield fires caused or contributed to the mine fire. As to which fire potentially contributed more embers, it provided no clear answer.
While Mr Incoll was not directly asked to express an opinion on the cause of the mine fire, he accepted that embers did spot into the mine from the Hernes Oak fire and could have spotted from the Driffield fire based on the prevailing weather conditions.80