Last year, Democratic lawmakers in Maine sent a letter to President Obama expressing concern about plans from Portland Pipe Line Corp. to reverse an oil pipeline so that it sends tar sands oil from Montreal to Maine.
Jim Murphy, a lawyer for the NWF, said last year's oil sands spill from the Pegasus pipeline in Mayflower, Ark., was an indication of the risk of older pipelines. Regulators said a defect from the 1940s led to the Mayflower spill.
He said he was concerned that Maine pipeline would suffer a similar fate because it was four years past a retirement age outlined by the Federal Energy Regulatory Commission.
"This is yet another reason any tar sands project in Northern New England is far too risky," he said in a statement Wednesday.
The grade of crude oil found in Canada is more viscous than others, making it difficult to clean up when spilled.
There was no statement from Portland Pipe Line Corp on NWF's critique.