In a formal minute, fast-track panel chairman Matthew Muir flagged that Santana had ‘‘deferred significant bodies of work’’, including groundwater impact assessments.
The gaps meant his panel faced ‘‘challenges ... in determining impacts and therefore imposing appropriate conditions where baseline information is not yet to hand’’.
Santana was asked how its application ‘‘compares’’ with the recently declined fast-track application to mine the Taranaki seabed.
The seabed mining project was withdrawn by Trans-Tasman Resources in February after the fast-track panel said in a draft decision that it planned to decline it.
In Mr Muir’s minute about Santana’s application, there was a list of work Santana had not yet produced, including an assessment of the ‘‘cumulative drawdown’’ on the Bendigo aquifer, an assessment of the impact of the proposed mine on wetlands, the design of water treatments and groundwater modelling of ‘‘seepage collection systems’’.
Permission is being sought to take around 110 litres per second from the aquifer, 6.5km west of the proposed mining site.
Mr Muir said the panel was concerned to know how the applicant would ‘‘approach and manage potential changes ... from a compliance, risk and operational perspective’’ that might be necessary once any deferred work happened.
Santana was asked to outline how it felt authorities would be expected to engage with the firm around any changes needed down the track.
Data gaps had been raised in written submissions to the panel and to a conference of groundwater experts convened by the panel earlier this month.
One of the experts, environmental engineer Alexandra Badenhop, had produced a review of Santana’s application for the Otago Regional Council.
She had written that recommendations in technical reports were weakened in the firm’s proposed water management plan, which ‘‘lacks timeframes for implementation or certainty around adaptive management responses’’.
The conference this month resulted in a joint statement on groundwater by the participating experts, which
said Santana was proposing triggering adaptive management actions if there were ‘‘exceedances or anomalies’’ identified during performance monitoring.
Santana-hired hydrogeologist Ryan Burgess said his ‘‘conceptualisation’’ of the hydrogeological system plus ‘‘seepage collection systems, performance monitoring and the ability to employ engineering controls’’ meant unacceptable seepage bypass risk was low.
Two other Santana-hired experts, geology engineer Eric Torvelainen and hydrogeologist Jens Rekker, agreed with this view.
However, University of Canterbury groundwater hydrology professor Dr Leanne Morgan disagreed due to ‘‘lack of data and a robust conceptual model’’.
There was support at the conference for ‘‘further peer-reviewed modelling’’.
Hydrogeologist Dr Dora Avanidou, Ms Badenhop and Dr Morgan agreed ‘‘more baseline information’’ was needed regarding level and movement of groundwater and water quality.
Santana’s water management plan lacked ‘‘triggers or clear timeframes for actions and does not require reporting on the management measures that are to be tested, or have been implemented, or actions that have been triggered (or their responses)’’, Dr Badenhop and Dr Avanidou said.
Dr Morgan said adaptive management may not be suitable as there were large-scale environmental risks, including potentially permanent contamination of the Ardgour and Bendigo aquifers and wetland loss beyond the project’s ‘‘wetland drawdown footprint’’.
‘‘Critical assessments of risk’’ were being deferred to post-consent and, even if adaptive management was suitable, Santana’s water management plan did not implement it effectively, she said.
There were also numerous recommendations in technical reports that ‘‘have not been translated into clear and enforceable consent conditions’’.
Dr Burgess said he thought the level of trigger-action response plans within a management plan should be a ‘‘negotiation between the applicant and the certifying body’’.
Santana has until June 22 to produce any updated proposed conditions and management plans for the fast-track panel to consider.
The mining company did not respond by deadline to a request for comment.
