Santana Minerals will not know whether its Bendigo-Ophir gold mine can proceed until late October, after a decision to set the project on the longest assessment timeframe requested by local authorities.

The decision follows a January conference where councils, government agencies and iwi argued the project was too complex to be assessed within the shorter timeframes initially sought by the applicant.

In a formal minute issued under the Fast-Track Approvals Act, panel convenor Jane Borthwick confirmed a 140-working-day timeframe for the decision, with the expert panel due to begin work on February 25 and a final verdict required by October 29.

Jane said the scale and technical complexity of the application, along with the number of unresolved issues and the fact the proposal falls under several different laws and agencies, justified both the extended timeframe as well as the appointment of a seven-member panel.

Outstanding information requests and the likelihood of expert conferencing, mediation or hearings were also factors in her decision.

The Bendigo-Ophir proposal, lodged by Matakanui Gold Ltd, a wholly owned subsidiary of Santana Minerals, includes open-cast and underground mining above Cromwell.

At the January conference, Otago Regional Council, Central Otago District Council and Department of Conservation all argued the project could not be properly assessed within a compressed fast-track timeframe, citing the size of the application, the number of matters still in contention, and concerns about the pace and depth of pre-lodgement engagement.

Iwi Kā Rūnaka also raised concerns about the scale and longevity of the project’s potential effects, including the possibility treaty settlement issues could arise.

Jane said if such issues were triggered during the process, additional time would be required for the panel to consider any amendments, though the overall statutory timeframe could not be extended.

The mining company initially sought a 30-working-day decision period and later indicated it would accept 60 working days.

“The applicant has not persuaded me that 60 working days is an appropriate timeframe,” Jane said.

“The application is substantial in scale and technically complex...more complex than the nearest comparable case.”

The expert panel will be chaired by Hon Matthew Muir KC, with members Gina Sweetman, Philip Barry, Roger MacGibbon, Tim Mulliner, Peter Kensington and Douglas Johnson, bringing expertise across mining, planning, environmental science, hydrology and geotechnical engineering.

A panel nominee put forward by Central Otago District Council was not included.

Santana Minerals chief executive Damian Spring said the confirmation of a firm decision date marked an important procedural step for the project, providing him a “clear line of sight”.

“From our perspective, certainty around process and timing is what matters, and we now have that.”

He said while a shorter time frame was preferable, the company was now focused on working constructively with the panel and other participants in the fast-track process.

Participant comments on the application are due on April 10, with the company’s response on April 17.

A spokesperson for mine opposition group Sustainable Tarras said group members were "relieved" to see the longer decision-making timeframe and the larger sized panel of experts.

"We are cautiously optimistic that this panel will be able to identify the gaps in the data, the overstated economic case, and the underestimation of environmental impacts," the group said in a statement released after the decision was published.

"We also remain hopeful that the panel will invite a wide range of affected parties, including ourselves. We have therefore taken steps to engage experts in areas where we believe we can add evidence to what we understand the agencies will be submitting."

Read more: Agencies seek more time, challenge engagement on gold project

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