Mi'kmaq leaders in Nova Scotia and their supporters are planning to slow down traffic on one of the province's main highways this week in a bid to stop construction of a natural gas storage facility near Alton.

The leaders are not pleased with what they say is a lack of consultation about the proposal to create an underground gas storage facility — and they're upset with the dumping of brine waste in the Shubenacadie and Stewiacke rivers.

"The Shubenacadie River has significance for the Mi'kmaq as a food source with cultural and political importance," Cheryl Maloney, president of the Nova Scotia Native Women's Association, said in a statement.

"Local citizens and First Nations both are concerned with water quantity and water quality issues and recognize the need for protection of local watersheds."

Cheryl Maloney

Cheryl Maloney says the protesters plan to light a ceremonial fire and set up a teepee Monday near Highway 102 north of Stewiacke. (CBC)

Maloney said the protesters planned to light a ceremonial fire and set up a teepee Monday near Highway 102 north of Stewiacke. The traffic slow-down won't happen until Wednesday morning.

Mi'kmaq communities have already set up signs along the highway between Stewiacke and Brookfield.

Brine is a solution of salt and water. The Department of Fisheries and Oceans gave permission to the Alton Gas Storage Project to dispose millions of litres of it into the river.

Maloney said the government has a higher legal obligation to get permission to do this from First Nations.

"The governments, it must have gone under the radar for them," she said.

"There was an environmental assessment, an initial one, but construction didn't start within the two-year period. We're asserting another environmental assessment should be done."

A crew of 70 people is currently working on a huge site where a rig is drilling holes for pipes that will carry water from the Shubenacadie River 12 kilometres away to dissolve salt caverns. Another set of pipes will carry the salty water back to the same river to be flushed away with the powerful current.

Alton natural gas storage

A crew of 70 people is currently working on a huge site where a rig is drilling holes for pipes that will carry water from the Shubenacadie river 12 kilometres away to dissolve salt caverns. Another set of pipes will carry the salty wastewater back to the same river to be flushed away with the powerful current. (CBC)

Alton Natural Gas Storage, a subsidiary of Calgary-based AltaGas, wants to store natural gas in three underground salt caverns that will be about 1,000 metres underground. AltaGas is the same Canadian company that owns the Heritage Gas distribution business.

Each of the caverns is expected to measure about 80 metres high by 50 metres wide, about the size of an average office building.

David Birkett, the president of Alton Natural Gas Storage, said in a statement that the company has been in "regular contact" with Mi'kmaq communities for the past eight years.

"We have met with Mi’kmaq about Alton Natural Gas Storage and will continue to do so in the days, weeks, months and years to come," he said.

"The Alton Gas Project is safe, regulated and sustainable and we want to make sure that there continues to be meaningful consultation and open dialogue with the community.”

Bob Haggle, who grew up around the Shubenacadie River, said he first became aware of the project a few weeks ago.

"My concern is what is on the fish and all the other marine life and marine vegetation that exists in those river systems," he said.

With files from The Canadian Press