Trans-Tasman Resources' seabed mining proposal lacks basic information about the process and does not take account of the sea life in the South Taranaki Bight.
That is the contention of Hawera woman Karen Pratt who spent two years researching the controversial proposal and has written a 700-page submission on it.
Her submission was presented to the Environmental Protection Authority which is holding hearings into TTR's application, and on Tuesday Mrs Pratt spoke at the EPA hearing in New Plymouth.
The company wants to mine millions of tonnes of ironsand from the seabed between 22 kilometres and 36km offshore from Patea.
Mrs Pratt had only 15 minutes to give her evidence, and she spoke quickly, using graphics on a screen.
She said the application didn't have enough information about ecosystems, and she made reference to reefs, sponges, fish and micro algae.
The application did not provide a noise plan, did not give solid information on economic benefits, did not deal with the desalination plant and grinder needed or the huge amount of heavy fuel oil needed to power it all.
The operation would use more fuel oil than the Queen Mary, Mrs Pratt said.
While climate change cannot be cited as an effect under exclusive economic zone legislation, she said air quality would be affected.
She was also concerned about the amount of light a sediment plume would block, and how sea life would be affected.
And she said the worst case scenario cited by TTR was not really the worst case.
Also addressing the hearing on Tuesday were Dr Will Edwards and Cassandra Crowley for South Taranaki iwi Nga Ruahine.
Dr Edwards referred to their "deeper knowledge" as he implored the four members of the EPA committee to see the matter through a "Maori lens".
"As an organisation operating in 20th century in Aotearoa New Zealand, it's incumbent on you to understand the power imbalance," he said.
The hearing chairman Alick Shaw said that was a challenge.
The 66 square kilometres of seabed proposed for mining was only a small portion of the ocean, Dr Edwards said, "but this is the world of Ngati Ruanui, Nga Rauru and Nga Ruahine."
The mauri (life force) of the place would be destroyed by lifting sand, sieving it and replacing it.
Ms Crowley said TTR had failed to lay out its proposal in simple terms most people could understand, and her people didn't have the resources to get through its thousands of pages of technical information.
She asked the committee to make a separate decision on the permissibility of the mining, without considering conditions.
Mr Shaw said that was not possible. The committee was in a "statutory box" and had to bring back possible conditions to submitters, whether the application was approved or not. Its job was to judge the physical effects on the environment.
He commended the Maori submitters for their respect, dignity and restraint.
Next Fred McLay spoke on behalf of Taranaki Regional Council, saying its primary concern was the effect of a sediment plume from mining on primary production.
He said the effect of the mining across the whole bight would be minor, but it could have major effects within two kilometres of the action.
The council submission neither opposed nor supported the mining. Mr McLay said it made that decision by balancing economic gains against environmental effects.
Mr Shaw said that was "going where angels fear to tread".