A fire hole identified 30 years ago in a now-disused section of the Hazelwood mine has been permanently extinguished.
Known by workers as ‘Old Faithful’, the fire hole would emit steam from the ground a couple of times a year, with workers occasionally seeing smoke.
Fire holes can occur naturally in some coal seams deep under the earth’s surface and most are dormant, but can reignite when exposed to oxygen, resulting in a rise in soil temperature.
Old Faithful persisted for years, with the accepted method of dealing with fire holes being to dig them out, hose them down with water, foam or fire retardant and fill them in with clay.
Hazelwood mine production manager Rob Dugan said the challenge with the traditional approach to dealing with Old Faithful was that the coal would eventually move, letting oxygen in once again.
“These holes can run deep and access is often difficult,” Mr Dugan said.
While the term ‘fire hole’ may conjure up images of a large, fiery void, Mr Dugan said the geological formation was actually a series of small cracks that stretched 20 metres up the northern wall of the mine.
Rehabilitation of the area, which began at the start of the year, allowed better access to Old Faithful and it has now been starved of oxygen.
“Heavy machinery was able to be brought in to dig down almost 6m, removing the hole’s core until the area was completely cool and at normal temperature,” Mr Dugan said.
“This entire hole and the surrounding area was then filled with compacted clay in several layers and then covered in topsoil.”
Rehabilitation of the eastern wall of the mine is expected to start towards the end of the year.
Hazelwood’s draft 2016 Work Plan Variation, which looks at rehabilitation of the mine, as well as environmental management and community engagement, is currently out for community consultation.
A public consultation session on the proposal will be held today from 10am-11am and tonight from 6pm-7pm at PowerWorks, Ridge Road, Morwell.
To RSVP, phone 5135 5000.
The draft document can be viewed online at www.engie.com.au or at the information session.
Feedback on the document can be provided by emailing hazelwood@au.engie.com
