Nova Scotia is once again considering a plan by a cement plant owner in Brookfield to burn used tires as fuel.

Lafarge Canada filed a proposal with the Department of Environment Thursday to use the scrap tires as "locally sourced, lower carbon fuels." Right now the plant uses traditional fossil fuels, including coal. Department of Environment staff will examine the application.

"They're going to be going through that process over the next few weeks assessing the application. There's going to be a lot of things involved with that, including community consultation and stakeholder information," said Margaret Miller, the environment minister.

2007 proposal scrapped

In 2007, the Progressive Conservative government said no to a similar proposal by Lafarge for burning tires at the same Brookfield plant.

Then-environment minister Mark Parent said there were "too many unknowns" about the emissions, but that some day if the technology allowed the procedure to be done safely it might be reconsidered.

Lafarge already burns tires at another kiln in Quebec and argues in its environmental assessment that allowing it to burn tires in Nova Scotia would reduce emissions.

"Scrap tires used for thermal energy in a cement kiln can reduce greenhouse gas emissions by roughly 30 per cent, for every tonne of coal replaced ... along with an expected 10 to 15 per cent reduction in [nitrogen oxides]," the company wrote in its proposal.

'We don't know enough about the science'

Miller said she does not think there is enough information about the proposal yet.

"We don't know enough about the science. Not for Nova Scotia," she said. "I know it's been done in other places but we want to make sure that the impacts to Nova Scotia are minimal if any. So we want to make sure that the science is sound before any approvals are given."

In its proposal, Lafarge says it will be working with a research team from Dalhousie University on emissions testing. Research funding will come from Dalhousie, NSERC, Natural Resource Canada, and Lafarge.

About one million used tires are created every year in Nova Scotia. Last year, the provincial agency responsible for handling them said it was searching for new ways to dispose of them. Lafarge says it would use up to 20 tonnes of used tires per day, or up to 6,000 tonnes per year.

The Lafarge plant is outside Truro. The company says if it receives approval it intends to begin construction of the tire-burning addition this summer and begin operations later this year.