By Dave Bryan

WILMINGTON (CBSLA.com) — The debate over the transport of crude oil by rail has returned as some California refineries have obtained permission to build terminals to accommodate oil trains.

Trains as long as 100 cars transport cheap crude fracked in North Dakota or oil sand mined in Canada to California.

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But experts on both sides disagree on whether that’s a good thing.

“It helps to get gasoline prices down,” said David Hackett, an oil company consultant. “Anything we can do to get gasoline prices down, in my view, is a good thing.”

But the Wall Street Journal says the prospect of more oil trains rolling through the state may be a reality soon. In fact, six cities across the state have now approved plans for oil-train terminals.

The California Energy Commission estimates that up to six trains a day could soon be coming.

Hackett says the move will accelerate a decline in gas prices across California and reduce dependency on expensive imported oil.

“The good it does is it backs out expensive imported crude oil that comes from long distance, places like, Saudi Arabia and Iraq and Russia,” Hackett told KCAL9 Political Reporter Dave Bryan.

But not everyone sees this as a good thing.

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“Transporting these 50 and 100 tanker car trains of crude oil that’s volatile and flammable and explosive, it’s really dangerous business,” said Diane Bailey, a senior scientist with the Natural Resources Defense Council.

Environmental groups and some community activists say the trains are dangerous, their cargo is explosive and the damage to the environment is serious.

Tom Williams, who worked on oil-related projects as an engineer for 20 years, serves as the senior technical adviser to the Citizens Coalition for Safe Community. He says the tank cars are problematic.

“The tank cars are not made for the type of oil that’s being shipped for such long distances and at high temperatures,” Williams contends. “As you increase the number of tank cars traveling 24 hours, 30 hours, 36 hours in a trip, each way, you’re creating a moving time bomb.”

A report from Hackett found that there have been seven serious accidents in the U.S. and Canada involving oil trains in the past 15 months.

But Hackett says the railroads and the oil companies are addressing the problems, including the tanker cars.

“Crude oil that’s been going into these cars meets the specification for those cars,” he said. “Nonetheless, the cars blew up when they fell off the tracks, right? And so, there is a full-scale redesign program for cars underway, as we speak.”

Hackett says that by early 2015, a decision is likely to be made about the next specifications for rail cars in order to make them safer.

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Meanwhile, some energy experts say they believe the first large-scale terminal will probably be built in Bakersfield. From there, they say, the oil could be transported to Los Angeles or San Francisco through oil pipelines. However, even some in the industry are not convinced that the oil-train flood will come anytime soon.