An environmental report for a rail expansion project at a Central California refinery that some East Bay residents fear would bring crude oil trains almost a mile long through their communities will be reissued and subjected to a new round of public comment, a San Luis Obispo County planning official said.

The Phillips 66 Santa Maria Refinery Rail Spur Extension Project envisions the delivery of crude oil by trains consisting of 80 tank cars and associated locomotives and supporting cars, according to the draft report.

Many East Bay environmentalists say they fear the trains could carry highly flammable, light crude from the Bakken oil fields in North Dakota and Canada through the East Bay.

This week, the Berkeley and Richmond city councils voted unanimously to oppose the transport of crude oil by rail through the East Bay, adding to a large body of commentary previously submitted during the draft report's initial public comment period.

Murry Wilson, environmental resource specialist for the San Luis Obispo County Department of Planning and Building, said his agency decided to recirculate the draft report due to the large volume and nature of comments received.

"In particular, the recirculated draft will address indirect impacts resulting from the project along the railroad's mainline outside of (San Luis Obispo) County's borders," Wilson said in an email, adding he does not know when the revised document will be completed.

Phillips 66 spokesman Dean Acosta said this week the Santa Maria refinery is "configured to run the heavier California crudes," but he stopped short of saying the refinery would not receive Bakken crude.

Aaron Hunt, spokesman for the Union Pacific Railroad, which serves Santa Maria and also owns the tracks that carry Amtrak's Capitol Corridor and Coast Starlight trains through the East Bay and South Bay, said a decision on the route would be made "at a later date."

Contact Tom Lochner at 510-262-2760. Follow him at twitter.com/tomlochner