As a New Brunswick company proposes a completely land-based salmon farm, two companies in Maine are vying to do the same on a much grander scale.

One of them, Whole Oceans of Bucksport, would be 33 times larger than the Grande-Anse operation proposed by RC Organic Northern, which expects to produce between 300,000 and 400,000 kilograms of fish annually.

The other one, Nordic Aquafarm, has two European land farms already producing Atlantic salmon.

Its proposed $500-million US farm at Belfast, Maine, would produce 110 times the volume of fish projected for the New Brunswick aquaculture operation.

"We've done this, we've built large facilities and we're confident about where we're going in the U.S.," said Eric Heim, president of Nordic, the Norwegian company behind the project.

We think that it is as fraught with problems as the [ocean] net pens were. - Ellie Daniels, Maine resident

"We've learned a lot, we've made mistakes and we've developed further."

The Belfast salmon farm, designed to produce 33,000 metric tonnes of salmon annually, would be located a short distance from downtown, near the shore of Penobscot Bay.

The plant would be built in phases and employ 120 people at full production.

Land-based aquaculture has its attractions. There are no salmon net pens in the ocean, there's no danger of farmed fish escapes, and effluent from the fish is recycled, filtered and "rigorously treated" before it is discharged via an undersea pipeline, a kilometre offshore.

But the company is facing tremendous opposition from neighbours and state environmentalists, largely because of the volume of water the operation would use and the sheer scale of the proposed operation.

"There's a lot of things wrong with this project," said neighbour Ellie Daniels. "But one of the major [problems] is water use, the discharge. And then the carbon footprint is gigantic on these things."

Nordic Aquafarms' proposed $500-million US salmon operation in Belfast, Maine would produce 33,000 metric tonnes of fish annually when all phases are completed. (Nordic Aquafarms.)

Daniels said Nordic Aquafarms proposes to use 7.7 million gallons of water a day, 30 per cent fresh, and 70 per cent seawater.

On top of that, a series of onsite diesel generators will be required to create the energy to pump and circulate water in roofed and enclosed oval pens rising several storeys from ground level.

"We think that it is as fraught with problems as the [ocean] net pens were," she said.

Spring start possible

Heim said the company has cleared many regulatory hurdles, and construction could begin as early as this spring.

He conceded it is a complicated undertaking.

"There's an enormous amount of know-how related to biology, water chemistry, operation, planning, design. These are complex projects."

A public meeting was held in Belfast about the proposed land-based salmon-growing plant. (Facebook)

Back in New Brunswick, Cooke Aquaculture, the province's biggest Atlantic salmon grower, is not ready to jump into eggs-to-harvest, land-based aquaculture.

Spokesperson Joel Richardson said Cooke is, however, moving to a system that sees young salmon spending more time on land before they are transferred to ocean pens.

The company is in the design phase for a new operation in Bayside, on the St. Croix River.

Land operations still 'experimental'

It would see young salmon grow to about 300 grams, more than twice the current weight, before they are transferred to sea pens.

"At this point full, land-based salmon grow-out facilities in general, of a significant volume, are still very much experimental around the world," he said.

He said land-based facilities to grow fish to full harvest size require large amounts of energy and infrastructure to recirculate the water.

"There are significant considerations in terms of the overall carbon footprint for building new facilities like that," he said.