It says the mining will add $147 million to New Zealand's export earnings and $302 million to the country's gross domestic product.
Phil McCabe, chairman of Kiwis Against Seabed Mining (KASM), said his group now finally had all the information it needed from TTR.
KASM's team of scientists and legal experts would take at least a week to analyse that information and come up with a submission against the mining, he said.
Others who wished to object would be able to download the KASM submission form from its website, kasm.org.nz, and use it themselves.
The group aims for a total of 20,000 opposition submissions.
As well as his worries about seabed mining, Mr McCabe, who runs a small accommodation business in Raglan, has a protest against deep sea oil drilling happening offshore.
"It's a huge ship, brand new, built by a foreign-owned company to harvest the resources that are owned by New Zealanders, very similar to the TTR story," he said.
The deep sea drilling project was an astounding symbol of the Government's extraction agenda, he said.
"Our Government is selling us out. Foreign-owned companies are coming in to harvest our resources and give us a fraction of their value."
Mr McCabe has employed someone to do his usual job while he fights the application.
"I'm just an everyday small business owner trying to get on with his life and maintain his business, but I can't stand and watch this stuff going on," he said.
The deadline for submissions on the ironsand mining proposal is 5pm on December 19. The EPA could begin hearing the application as early as February 21.
Chief executive Rob Forlong said the authority was skilled up and well able to ensure sustainable management of offshore resources.
The committee to hear the application will be chaired by independent commissioner Greg Hill and consist of EPA board representative Gillian Wratt, Brett Rogers, William Kapea and Stephen Christensen.
All submissions would be considered, and all submitters would have a chance to speak and would get regular updates on the process, Mr Forlong said.