This wasn't the "deep sea drilling" that the Greens had made such an issue when the Government put through legislation two years ago. This would be dredging the seabed in 20m-40m of water about 30km out from Patea.
The company proposed to mine ironsand to a depth of 11m using a ship that would suck up the excavated sediment, extract the iron ore magnetically and drop the mud and sand back into the trench.
It would drop the material from the end of a tube 4m above the sea floor and the finer particles would be carried some distance by the current, much like the silt carried down rivers that is visible in the sea from aircraft every day.
This "plume" of fine sediment would fan out from the mine site, usually southeasterly, until it dispersed. The Environmental Protection Agency was advised it would reduce sunlight in the water by 7.6 per cent and algal and plankton growth by perhaps 10 per cent.
Beyond that, the worst possible effect might be noise heard by marine mammals, which include the highly endangered Maui's dolphin, though the agency had no evidence they would be disturbed.
In fact the agency had no hard evidence of any harm of any kind, despite the application attracting the usual attention of environmental watchdog organisations and their commissioned scientists.
The agency operates through appointed decision-making committees drawn from the planning community. This one was chaired by Greg Hill, an Auckland-based resource management consultant, and included an agency board member, Gillian Wratt, a New Plymouth petroleum consultant, Brett Rogers, an expert in the Maori world view, William Kapea, and environmental lawyer Stephen Christensen.
The committee organised conferences of experts on all the forms of life that might possibly be harmed by disturbed sediment in the South Taranaki Bight and the experts the committee respected could not find much harm at all. At least, I couldn't find any actual harm in the evidence summarised in a 248-page report issued by the committee when it turned the application down.
It turned it down because it thought there might be harm of which it was unaware. The decision-makers have seized on any uncertainty the scientists acknowledge.
Scientists are ever ready to acknowledge the limits of their knowledge - it is the way science works - but if you read this report online as I did you might also get the sense the experts are a bit more confident of their knowledge than the decision-making committee seemed to be.
It is a case of the "precautionary principle" gone mad. The precautionary principle surely requires some evidence of possible harm.
It cannot mean that activities are forbidden on the principle that "we don't know what we don't know". It is not fair or viable for environmental law to sanction decisions based on purely speculative possibilities of harm.
Nor is it fair to hold the absence of evidence against applicants. It means they are damned if they can find harm and damned if they cannot. This decision has shocked industry generally. It was made by an agency set up by the present Government to be a quicker and fairer decision-maker than those operating under the Resource Management Act.
Trans-Tasman Resources have taken the agency's decision to the High Court, where it will face argument from the Environmental Defence Society that the Exclusive Economic Zone Act "is clear in its requirement for caution and environmental protection to be favoured in the face of uncertain or inadequate information".
It will be interesting to see whether a judge finds the caution in this case to be rational. If it is there is going to be very little New Zealand can do with wealth within its reach.
