The ruling, which aims to cut carbon emission by 30% over 25 years, is likely to gut the already waning domestic coal industry, according to numerous concerned coal producers.

With efforts to build coal terminals thwarted in Washington and Oregon, producers could be looking to the north to import their product overseas.

Much of the coal currently moving through the Lower Mainland is metallurgical coal from British Colombian mines in the Kootenays or the northeast.

The majority of the coal ends up at Westshore Terminals at Deltaport, where an average of six coal trains arrives daily.

Only two trains carrying US thermal coal pass through White Rock and South Surrey daily on their way to Westshore.

Westshore handled nearly 31 million tonnes of coal last year.

A $C275million ($A269 million) upgrade is underway at Westshore but the company said it would result in only a minimal increase in annual capacity to 35Mt.

The company said it expected no short-term impact on its business from the US regulations.

"Coal opponents have been giving the impression it's going to be open sesame – that there's going to be all this US thermal coal pouring into BC," Coal Alliance spokesman Alan Fryer said.

"It seems to me that's not going to be the case."

Even with the emission cuts, the US still expects 30% of its electricity to come from burning coal in 2030.

"In terms of its impact on BC, we don't feel it's going to be significant at all because there's limited capacity," Fryer said.