Macraes expansion permitted

Consent extends life of pit

AN expansion to the Macraes gold mine will allow an extra 2.8 million tonnes of ore to be extracted.

A hearing commissioner appointed by the Otago Regional Council, Dunedin City Council and Waitaki District Council recently granted consents for OceanaGold to increase the size of its Coronation North Pit by 25.8ha.

This would allow an extra 2.8 million tonnes of ore to be extracted, which equated to more than 100,000oz of gold.

The operation, about 30km northwest of Palmerston, produces about 5 to 6 million tonnes of ore a year.

The consent will extend the pit’s mining life into 2021, although the company plans to operate at the site until at least 2024.

Macraes operations general manager Matthew Hine said the consent was provisional and he did not want to comment until appeals closed on November 7.

The company would also extend the pit stability layback to the south and east of the pit as a safety measure, which would increase the size by a further 7.6ha.

It would partly backfill the western end, where mining has been completed, with about 19.3 million tonnes of waste rock, which will help stabilise the pit wall.

Overall, the amount of disturbed land was 50.9ha.

However, it would surrender existing consent rights for a 52.9ha area which was considered to have the highest conservation value of anywhere in the site.

Hearing commissioner Brent Cowie said this meant ‘‘overall there is a net benefit to environmental quality’’ from the consent.

In his decision, he said the amenity values of the Macraes mining area were ‘‘quite low’’ due to previous and existing opencast mining.

While gold at the site was a finite resource, without the consents ‘‘the employment of large numbers of staff would be jeopardised’’, Dr Cowie said.

The consent said Macraes had 575 employees and contractors at the site, and a further 25 in its Dunedin office.

The application was limitednotified, meaning only people and organisations with a direct interest in the consent could submit.

Two submitters appeared at the hearing.

One spoke about coming to an agreement with the company around nighttime access to the haul road.

The other said the consent should not be granted as previous consents were not fully complied with.

The Department of Conservation raised the concern the pit extension could affect local groundwater levels in the basalt contact wetland, Dr Cowie said.

‘‘This was reviewed independently by two companies with expertise in geohydrology, and both concluded that this was improbable.’’

OPERATIONS at Macraes Mine require fossil fuel use in a way that could soon be seen as unsustainable, a hearings commissioner says.

However, he was unable to take this into consideration under the law when granting consent for the project’s expansion.

Independent commissioner Brent Cowie granted a raft of consents for the expansion of the site this month.

However in his decision he noted ‘‘the extraction of relatively small amounts of gold from huge volumes of orebearing rock’’ used large volumes of fossil fuels.

‘‘Not least in the massive trucks which carry rock to the processing plant and which each use about 300 litres of diesel an hour.’’

As the effects of climate change became ‘‘more daunting and challenging’’ it was possible the open cast mining of the type carried out by OceanaGold at Macraes would someday no longer be considered sustainable, at least in New Zealand, he said.

‘‘At this time, however, given the low weighting given to consideration of climate change in the [Resource Management Act], this is not a matter that I have given any significant weight to.’’

Dr Cowie’s comments echo the debate concerning a consent granted last month by the Environmental Protection Authority related to OMV’s intention to drill an oil and gas exploration well in the Great South Basin.

Submitters became frustrated at the hearing that they were restricted to the consent at hand and unable to express views on the wider project, including its effects on climate change.

Environment Minister David Parker has said climate change was within the scope of its review of the Resource Management Act, which has jurisdiction up to 12 miles off shore.

However there were no plans to do the same for the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act, which has effect beyond this point.