Greenpeace has lost a bid to have the granting of Anadarko’s offshore drilling permit declared erroneous in the High Court.

Greenpeace’s case was based on Anadarko’s omission of annexes from the impact assessment it was required to submit to the Environmental Protection Authority (EPA) to be granted a petroleum exploration permit for an area in the Taranaki Basin.

Anadarko is drilling an exploration well it began within the permit area on November 26.

Under transitional provisions that apply before the Exclusive Economic Zone and Continental Shelf Act came into force, Anadarko had to submit an impact assessment to the EPA before petroleum exploration activity could start.

Anadarko submitted an impact assessment for the Taranaki Basin drilling on September 13. It was reviewed and found to be incomplete.

Anadarko provided clarification of some matters, and supplied a revised impact assessment addressing these on September 26.

The material was reviewed, and the 150-page impact assessment found to be satisfactory for the purposes of the act.

Appended to the impact assessment was a further 73-page discharge management plan – addressing management and avoidance of any potential pollutants and including emergency spill response procedures – that was submitted to Maritime New Zealand.

Greenpeace submitted the impact assessment had been incomplete, as it did not have the annexes to the discharge management plan.

The EPA erred in accepting the impact assessment, and should have returned it as incomplete, Greenpeace said.

The High Court ruled the evidence did not indicate any error by the EPA, and said there was no evidence that resubmitting the impact assessment supplied in the discharge management plan would achieve any meaningful objective.

A "careful and proper consideration of the completeness of the impact assessment" has been undertaken by the EPA. In addition, the impact assessment was independently and internally reviewed, Justice Mackenzie found.

The EPA welcomed the High Court’s decision, and said it was satisfied Anadarko provided sufficient information in its impact assessment on the measures it intended to take to avoid, remedy or mitigate any adverse effects on the environment.

Anadarko must complete the Taranaki Basin well by May 31 next year to comply with the permit conditions.