* Maine pipeline plan hinges on flows to Montreal
* Recent spills inflame Canadian oil debate
* Towns oppose oil sands, line passes through tourist zone
By Dave Sherwood
SOUTH PORTLAND, Maine, May 22 (Reuters) - The little-knownoperator of a pipeline linking Montreal and Maine is studyinghow to make the line the first route to get Canadian oil sandscrude to an Atlantic deepwater port, but the plan relies onsupplies that may not be available for years.
The Portland-Montreal pipeline - principally owned by topCanadian oil refiners Suncor Energy Inc, Imperial OilLtd, and Royal Dutch Shell Plc - has alreadyspent about $6.5 million to prepare for a reversal of the lineso it can carry heavy oil sands crude from Quebec to Maine'sbiggest city, according to regulatory filings from 2011. Thepipeline now mainly carries imported crude to Canadianrefineries.
The plan to reverse the 236-mile (378-kilometer) duct hasalready made New England green groups and some lawmakersbristle, opening up an eastern front in the national energy andclimate change debate. But its fate may hang more heavily on theavailability of oil sands crude from points west than it does onlocal support.
"This is not something that's going to happen overnight,"said Larry Wilson, chief executive of the Maine-based PortlandPipe Line Corp, citing the need for enough supply reachingMontreal and demand along the Eastern Seaboard.
"But we are currently operating under capacity, and lookingfor every opportunity to maximize use of our assets, includingreversal," he said of the pipe, which was designed to move asmuch as 240,000 barrels per day.
Canadian pipeline company Enbridge Inc - operatorof the world's largest pipeline system - has proposed reversingits so-called 'Line 9' pipeline between Sarnia, Ontario, andMontreal, to get Alberta oil sands crude into Quebec.
That would eventually allow it to supply Quebec with just300,000 bpd, too little to sate Quebec's oil refineries and fillthe line to Portland at the same time.
"Our intention is to feed those two refineries but I guessthey'll still be a little bit short," Al Monaco, Enbridge'schief executive, told reporters earlier this month when asked ifthe company had mulled supplying crude to the Portland line.
LOCAL RESISTANCE
Canada's oil sands are seen as a secure source of oil forthe United States, but they are located in landlocked northernAlberta.
Canadian oil sands producers and Canadian authorities arekeen to move more oil to U.S. and overseas markets, but plans,including TransCanada Corp's Keystone XL pipeline tothe Gulf of Mexico and Enbridge's Northern Gateway to thePacific, have been delayed by controversy and political rancor.
Some oil sands crude does move to Vancouver on Canada'sPacific Coast, however, on Kinder Morgan Energy Partners LP's Trans Mountain pipeline.
Opposition to pipeline projects has stiffened after recentspills of oil sands crude on lines in the middle of the UnitedStates, including one outside Little Rock, Arkansas, in March,and another in 2010 that poured 20,500 barrels into a waterwaynear Kalamazoo, Michigan.
In Maine, several communities have passed nonbindingresolutions expressing opposition to transporting oil sandscrude through the Portland pipeline, which passes through theSebago Lake watershed, a regional tourism hub and the source ofwater supply for Portland, Maine's largest city.
"There's so much to lose that Maine people aren't willing tosit on their hands and wait until the company decides they areready to propose something," said Dylan Voorhees of the NaturalResources Council of Maine.
U.S. Senator Angus King, an independent who caucuses withthe Democrats, has called the company a "sound environmentalsteward" for its good record on spills. But he wrote in a recentconstituent letter that he would request that any proposal totransport heavier-grade diluted bitumen on the line face fullfederal permitting and environmental scrutiny.
In 2008, the pipeline company submitted a proposal toreverse the flow and transport Canadian crude - though the planwas later ditched for economic reasons.
At the time, the U.S. State Department determined theproject "did not constitute a substantial change in scope..."from the original permit, according to documents obtained byReuters.