Opponents of the Northern Gateway pipeline are threatening to turn their sights on CN Rail, as at least one Alberta oil company explores the possibility of transporting oil sands crude to the B.C. coast by rail.

Sixteen environmental groups have signed a letter to CN CEO Claude Mongeau questioning the rail industry's safety record.

The letter specifically cites a 2005 train derailment that spilled thousands of litres of oil and toxic chemicals into Lake Wabamun, in Alberta, and another accident the same year that dumped caustic soda into the Cheakamus River, killing half a million fish and poisoning the river for kilometres.

The groups say that if CN decided to move forward with oil transport plans, it would face major opposition and risks to the company.

The Port of Prince Rupert confirms that it has had "very preliminary" talks with Nexen Inc., about using trains to bring oil from Alberta to the north coast port city.

Production in the Alberta oil sands has outstripped pipeline capacity, and several projects have been proposed to expand Pacific exports -- including Enbridge's Northern Gateway pipeline into Kitimat and an expansion of Kinder Morgan's existing pipeline into Metro Vancouver.

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