The $4.5 billion gold mine is going through the fast-track process and the panel chairman Matthew Muir said yesterday he was becoming ever more mindful of the deadline for making a decision on the entire project.
One-day hearings on particular subjects are set down for two weeks. The second week started yesterday, centred on water.
Mr Muir was not helped yesterday in getting some speed on in something of a marathon session around water issues, with 11 expert witnesses contributing to the hearing.
Santana Minerals had six witnesses discussing the project.
Fish & Game expert witness Kate McArthur said last week the evidence provided by the applicant around water brought a cascade of uncertainty, with a vacuum of information. She spoke last week as she was unable to attend yesterday.
Senior hydrologist Ryan Burgess, appearing for the applicant, said there was always more you could do but at some stage you had to be happy with the information you could get and what could be done with it.
Mr Muir asked Mr Burgess if he was of the opinion that ‘‘you could always do more but you think you have done enough’’. Mr Burgess said yes.
He outlined the work which had been done to get data, including hundreds of drill holes and digital readings which helped create a baseline.
‘‘While there are some limited data gaps, we aim to fix those. In my opinion the base line provides a reasonable base for likely drawdown patterns and seepage migration,’’ Mr Burgess said.
There were further programmes proposed to fill those gaps and more information would come further along the project.
He said this was standard practice for projects this size.
Environmental Defence Society expert witness Leanne Morgan requested more drilling holes be put in the ground and more records on the water flows.
She knew it was expensive to do more drilling but more was needed for the receiving environments of water. She said more monitoring should be carried out. Many doubts remained around ground and surface water, she said.
Senior hydrogeologist Jens Rekker, appearing for the applicant, said Shepherd’s Creek and the Rise & Shine valleys had steep topology, which would help reduce the seepage.
When asked about climate change, Mr Burgess said this would centre on the impact of the mine when it was closed. The mine is set to be open for drilling and extracting gold for 10 years.
He said the modelling had shown the more extreme estimation of the impact of climate change would have no real different impact on the closed mine site.
Mr Muir said he was mindful of the time taken in the one-day hearings with a decision due at the end of October. A preliminary decision to discuss conditions was coming in September and Mr Muir asked how that could be done when more information was needed from Santana around water.
Environmental geochemist Paul Weber, appearing for the applicant, suggested a bond be put forward by the applicant, which had been done at the Waihi mine.
Environmental Defence Society expert witness Professor Jennifer Webster-Brown, of University of Canterbury, said she was surprised the applicant had not looked at an alternative to the large pit lake she described as a 3 million-tonne lake with arsenic sitting on the site for 110 years.
‘‘It is not just a problem for the ducks when landing on it but just the perception of it: a large toxic lake is just going to sit there and not really change for 100 years.’’
She said she was not really seeking an answer to the question from the applicant but making an observation.
