High voltage power lines between the Hazelwood open cut and the Morwell community could be forced to move to allow safe rehabilitation of the mine’s northern batters.
GDF SUEZ technical services manager Peter Faithfull said rehabilitation of the mine’s northern walls could require them to be “sloped back” before they could be capped with soil and clay.
However Mr Faithfull said the process could impact on the stability of major infrastructure along the mine’s northern wall, depending on the rehabilitation technique.
The high voltage lines, owned by SP AusNet, run alongside two other big ticket pieces of infrastructure in between the Hazelwood mine and Morwell township’s southern edge – the Morwell main drain and the Princes Freeway.
“The underlying issue with all of this is, is that that is significant infrastructure that, if you don’t install and monitor for geotechnical stability in the area, and if you don’t get that right, you could potentially impact those assets,” Mr Faithfull said.
Counsel Assisting the Hazelwood Mine Fire Inquiry Melinda Richards moved to clarify Mr Faithfull’s comments heard on Thursday.
“When you identify infrastructure positioned above the batters as a factor or constraint, you’re not suggesting that any of that infrastructure has to be moved, are you?” Ms Richards asked.
“Potentially, yes,” Mr Faithfull said.
Ms Richards then pressed about the timing of the rehabilitation schedule, with a current phase involving a section of northern batter being rehabilitated by 2019, with further northern works to be completed by 2032, and GDF SUEZ’s communication with the authorities responsible for the major assets.
“This is work that’s to be completed in about five years’ time and at present as you sit here you can’t say whether it’s going to be necessary to move the high voltage power lines or close the freeway?”
“That’s right,” Mr Faithfull said.
“Once the stability analysis, and we understand the nature of that batter and what we’re trying to do with it, once we’ve determined that, then we can start to understand the impacts and the modelled impacts on each of these areas.
“And if it did come to a point where we need to talk to SP AusNet regarding their HV power lines, then that’s a discussion we’ll have at the time and we’ll talk to and engage with them.”