The Legislature will decide Tuesday whether to override the veto of a bill requiring the state to study the risks of transporting oil – a topic that gained relevance this weekend when oil-filled train cars exploded in a Canadian town near the Maine border.

The purpose of the bill is to ensure that the Maine Department of Environmental Protection specifically looks into risks related to transportation of so-called tar sands oil, which has recently sparked controversy in the state.

Environmentalists fear the Portland Pipe Line Corp. will transport the heavy crude from Canada. They say it is more corrosive than the oil that currently runs through its Portland-to-Montreal pipeline. Portland Pipe Line, which hasn’t come forward with a specific plan to transport tar sands oil, argues that it’s no more dangerous.

The derailment and fiery explosions that followed killed several people and destroyed buildings Saturday in Lac-Megantic, Quebec. The train was not carrying tar sands oil, but a light crude from North Dakota that was supposed to be transported through Maine to the Irving Oil refinery in Saint John, New Brunswick.

Emily Figdor, director of Environment Maine, said she doesn’t believe that trains are currently transporting tar sands through Maine because that refinery is not equipped to process it.

Still, she thinks the accident in Canada is relevant to the debate about the potential for tar sands oil flowing through the pipeline in Maine.

“You can see firsthand the destruction it can cause. It is a really unfortunate and powerful reminder that this is serious business,” she said.

Rep. Ben Chipman, I-Portland, who sponsored the bill, said the incident “brings attention to the whole issue of transporting oil and what impact it can have on communities.”

Also Tuesday, a joint order sponsored by House Majority Leader Seth Berry, D-Bowdoinham, would direct the Legislature’s Transportation Committee to meet and issue a report on the transportation by rail of hazardous materials, including petroleum products. The report would be issued by Dec. 6 and could lead to introduction of a bill.

“Given the magnitude of this tragedy, we must do all that we can to prevent another disaster like this from taking place,” Berry said of the Quebec train crash.

Gov. Paul LePage vetoed Chipman’s bill on July 2 because, he said in his veto message, the DEP “is already investigating such transportation and going beyond the scope of the bill to develop spill response plans to ensure that the impacts of a potential spill in Maine will be minimized.”

The message referred to a 325-page report of the department’s “initial study efforts.”

That report was developed from training on tar sands oil — also called oil sands products — conducted in December for employees of the DEP and the U.S. Environmental Protection Agency.

The report says those agencies “deemed it important to know more about the characteristics of this type of petroleum so they could better plan for potential incident responses if an accident occurred” and focuses on transportation by rail.

The report notes that the Montreal, Maine & Atlantic Railway — the company whose train derailed in Canada — “would be the most likely carriers of (oil sands products) through Maine.”

The DEP is continuing the study by identifying places in Maine where oil is transported by rail and developing plans for how to respond to an oil sands spill, said the department’s spokeswoman, Jessamine Logan.

Melanie Loyzim, director of the DEP’s Bureau of Remediation and Waste Management, said the vetoed bill would require the department to create summaries of studies that have already been done and are publicly available, taking time from the new work it is trying to do.

Chipman originally introduced the bill as a two-year moratorium on tar sands oil passing through Maine, but amended it after learning that enacting such a ban was not within the state’s purview.

It is now a resolve directing the DEP to “conduct a review of the environmental and public health and safety risks associated with the handling and transportation by road, rail, water and pipeline” of tar sands oil, looking at its characteristics, resources for dealing with a spill, the impact on communities a spill would have and studies of previous spills in Arkansas and Michigan.

Chipman said he hasn’t seen anything in writing that indicates the DEP plans to study the potential effects of a tar sands oil spill.

“I’m not convinced we would get it without the bill,” he said.

Rep. Larry Dunphy, R-Embden, said he hadn’t seen the study, but “if the governor is telling me a study is being done, I assume it’s being done.”

Dunphy, who represents towns, including Jackman, through which the railroad’s trains go, said he will support the governor’s veto.

“The situation in Canada is an absolute tragedy,” he said. “Are we going to stop transporting oil? I don’t think so.”

The House of Representatives approved the bill in a 97-50 vote.

Chipman said what happens Tuesday morning “depends on who is there.”

Leslie Bridgers can be contacted at: 791-6364 or at

lbridgers@pressherald.com