PORTLAND – City councilors are expected to vote Wednesday on a measure that would prohibit the city from using fuel refined from tar sands oil in its municipal fleet, Mayor Michael Brennan says.

The policy was reviewed by the council’s Transportation, Sustainability and Energy Committee, which voted unanimously for the ban, Brennan said.

Tar sands are a mix of sand and viscous petroleum bitumen, or “tar,” mined in Alberta, Canada, and used to produce a synthetic oil. The material requires extensive processing and is used to make a wide range of products, from asphalt to aluminum cans, as well as fuels.

The Portland policy does not try to block the transport of tar sands oil because the city has no jurisdiction over whether — or where — a pipeline would carry oil sands in Maine.

Environmental groups say a 62-year-old Exxon pipeline — actually two parallel lines that stretch 236 miles from Montreal to South Portland — is being considered for the transport of tar sands oil, which has been linked to a higher incidence of pipeline spills and which leaves a heavy residue at spill sites that is difficult to clean up. The pipeline stretches through Casco along the Crooked River, passes Pleasant Lake and Parker Pond and then follows Route 302 past Sebago Lake to South Portland.

Enbridge’s plans for a pipeline between western Canada and Montreal include having the flow reversed, making it possible to transport tar sands oil to Montreal.

The company says it currently has no plans to transport tar sands oil from Montreal to South Portland.

On Saturday, Casco residents approved a municipal resolution that opposes transporting tar sands oil through the pipeline. It was the first such vote in Maine.

Emily Figdor, executive director of Environment Maine, said the environmental group helped Portland officials prepare the city’s measure, which was introduced at the committee level by City Councilor David Marshall. Other communities might be considering similar measures, the group says.

Brennan, the Portland mayor, said the city “places such a premium” on Casco Bay, the waterfront and the availability of clean drinking water from Sebago Lake that it was imperative to oppose the transport of tar sands oil through the area.

He said Wednesday’s vote indicates that opposition to tar sands oil is “absolutely gaining traction” statewide. There is significant opposition from many quarters, he said.

Dylan Vorhees, clean energy project director for the Natural Resources Council of Maine agreed.

“Landowners, clammers, water district trustees, wilderness guides, voters at town meetings, and others are all saying that sending tar sands across Maine for export, is an all-risk, no-reward proposition for Maine’s people, environment, and economy,” he said.

On Jan. 26, a few days after the council takes up the resolution, a rally to protest transport of tar sands oil will be held in Portland.

The event is expected to draw opponents from all over New England.

Staff Writer North Cairn can be contacted at 791-6325 or at:

ncairn@mainetoday.com