BOSTON – The river that runs past a proposed liquefied natural gas terminal in Fall River, Mass., isn’t safe for frequent traffic by massive LNG tankers, the Coast Guard ruled Wednesday in what could be a fatal blow to the controversial project.

“It kills the project, as proposed,” Coast Guard Senior Chief Richard Uronis said.

The project is one of several proposals to locate an LNG terminal in New England.

Three proposals on the drawing board in Maine have sparked opposition from Canadian officials and others, who question whether large tankers could safely navigate Canadian waters leading to the terminal sites.

The Coast Guard determined the tankers wouldn’t have sufficient space to safely navigate between two bridges that are about 1,100 feet apart on the Taunton River. The Coast Guard expressed similar concerns in March 2006, but said then it was waiting for revisions from Weaver’s Cove Energy, which proposed the LNG terminal.

“Vessel masters would face extraordinary navigational maneuvers when transiting the waterway and the safety risks are too great to favorably recommend the waterway as suitable,” said Coast Guard Capt. Roy Nash, captain of the port for southeastern New England, which includes southern Massachusetts and Rhode Island. Nash has jurisdiction over vessel traffic in his region.

Fall River Mayor Edward Lambert said he was “joyous” over the Coast Guard report and added it was time for Weaver’s Cove to abandon its plans in Fall River.

“I think it does show you can beat very wealthy, powerful interests if you have right on your side,” Lambert said. “We know this is not over until it’s over, but this is, I think, a near death blow, if not a fatal blow.”

Weaver’s Cove spokesman Jim Grasso said the project was far from finished and the company would appeal the Coast Guard decision. He said Nash brought up new concerns the company didn’t have a chance to respond to and ignored tests that showed the tankers could successfully navigate the river.

“We feel we can do this safety and securely,” Grasso said.