The Hazelwood mine is an open-pit brown coal (lignite) mine located in the Latrobe Valley in the Australian state of Victoria, around 150km east of Melbourne. The mine, which is owned and operated by GDF Suez Australian Energy along with its partner Mitsui & Co, feeds coal directly to an adjacent 1542MW coal-fired power station.
The complex supplies up to 25% of Victoria's energy needs and more than 5% of Australia's energy demand as a whole, making it an important local and national energy hub.
Disaster struck Hazelwood on 9 February 2014 when a wildfire that started at around 1:30pm burned through a local timber plantation before reaching the mine, setting alight two separate coal faces at Hazelwood's disused open-cut site. Coal seam fires are notoriously difficult to bring under control, especially in open-cut mines where flame-fanning air flow is abundant.
Victoria police believe the wildfire was not a natural occurrence; there is evidence that 'test fires' had been lit on 28 January and the day of the wildfire itself, suggesting an arsonist lit the fire deliberately. "This person took actions that were very, very calculated and designed to create significant damage to the community," said Victoria Police chief commissioner Ken Lay.
Firefighters from the Country Fire Authority (CFA) and the Metropolitan Fire Brigade scrambled to fight the fire, joined by representatives of GDF Suez and other firefighters who travelled in from around Australia as the blaze continued. The initial concern for emergency response crews was the potential for the fire to spread to the adjacent power station.
"Our concern was not to allow any fire to get into the conveyers that take the coal into the power station," said GDF spokesman Trevor Rowe. Indeed, 80 non-essential staff members were evacuated from the plant as smoke began to drift into the facility during the afternoon. The power station was never directly threatened by the fire, but the mine itself was to continue burning dangerously for 45 days.
Ash and smoke from the mine fire caused a rapid deterioration of air quality in the surrounding area, which particularly affected the nearby town of Morwell. Some vulnerable residents were advised to relocate temporarily, while schools and other services were closed. The situation would have been eerily familiar for many Morwell residents, as the town suffered the effects of a similar bushfire-caused coal seam fire at Hazelwood in October 2006.
Carbon monoxide exposure was the primary concern, especially for the crews fighting the fire, while experts warned of abnormally high levels of particle PM2.5, a class one carcinogen. Long-burning coal seam fires can create health problems, especially respiratory issues, over extended periods. Australia's Environment Protection Authority (EPA) had already fixed carbon monoxide and particulate monitors around Morwell, a capability not shared by many coal mining communities in developing countries.
A helicopter dumps water on the mine fire during the course of the Hazelwood firefighting operation. Water is often insufficient to actually extinguish coal seam fires, but it can cool down surface temperatures so that more sophisticated compressed air foam systems (CAFS) can be deployed without being burned away by the heat.
Wind is another major concern when fighting coal seam fires - firefighting efforts at Hazelwood were regularly disrupted by blustery conditions that threatened to fan the flames in unpredictable directions, with experts concerned at one point that wind was pushing the fire towards the power plant. Fortunately, the fire came no closer than 200 metres to the facility.
CAFS were used on Hazelwood mine's northern batters (the ridged slopes of an open-pit mine), deployed from heavy-duty fire trucks originally built to respond to aviation disasters. CAFS works by chemically attracting brown coal to the foam, which absorbs into the coal, helping to smother the fire and reduce smoke release. The Hazelwood fire marked the first time CAFS units, originally developed in the US, have been used on a brown coal fire in Australia, and crews noted that it slowed down smoke production significantly.
Hazelwood's northern batters were the main locus of firefighting, especially as this area was the main source of the smoke and ash drifting over the edge of Morwell just 400 metres away. Still, crews also had to tackle fires on the southern batters, which proved tricky to reach. GDF Suez has had to defend itself from accusations that it was unprepared for an event like this, even after the mine fire in 2006. "Had they rehabilitated the southern batter, then half the fire the firefighters are being forced to fight would not be ablaze at the moment," said trade union leader Luke van der Meulen on 5 March.
The fires burned throughout the nights, radiating an orange glow over the surrounding area. Fire authorities monitored the underground heat generated by the fire and looked for hotspots using thermal imaging line scans. In the hottest spots, temperatures reached around 1,000°C, but thermal scans also tracked the gradual containment of fire activity, which was reduced by more than half between 11 February and 24 February.
"It's great to be able to show these line scans to firefighters and support staff so they can see that their hard work is paying off," said CFA fire services commissioner Craig Lapsley. "It also demonstrates to the local community that we are making progress."
Forty-five days to make a mine fire safe might sound like a long time, but it's a testament to the daunting firefighting task that coal seam fires represent. When the Great Morwell open-cut mine in the same area caught fire in 1902, explosives were used to breach the Morwell River and flood the mine. In the 2014 fire, flooding the area was considered a last resort due to the impact of disrupting production at the Hazelwood complex.
In India, meanwhile, an underground coal seam fire first detected in 1916 has been burning for almost a century beneath a section of the Jharia coal field in Jharkand. The blaze has caused significant subsidence in the land, driving local people away and causing major health problems for those who remain.
After an extensive and exhausting effort, the Hazelwood mine fire was finally declared safe on 25 March. Fire crews visited local schools that had been affected by the fire to demonstrate their equipment to a crowd of students. Meanwhile, the post-fire clean-up operation has begun in Morwell, with the Victoria government allocating A$2m to remove the ash left by the fire. "We see this as a valuable contribution to help the people of Morwell get back into their regular routine as quickly as possible," said Victoria's Deputy Premier Peter Ryan.
But as with most coal seam fires, this is no clean-cut end. The mine has been handed back to GDF Suez, which will collaborate with local fire authorities as it continues to monitor the underground hotspots that remain. A judicial inquiry has been called to look into the causes of the fire, the mine owner's preparedness, the emergency response and the regulation of the mine, with its findings due to be reported in August 2014.
In an article for The Conversation, University of Queensland professor of occupational health and safety in mining David Cliff argued that improved fire detection and prevention measures need to be put in place, no matter the financial cost. "Any argument about the cost of controls must recognise the direct and indirect costs of the current incident to Victorians - and particularly the locals living in and around Morwell."