Facing a looming federal deadline for moving dirt, managers of California's bullet train project are trying to clear away legal and political impediments that threaten to delay the project.

They resolved two of the lawsuits that challenged the project on environmental grounds, but two legal requirements - one in federal law, another in the bullet train bond issue - remain as potential hurdles for building the initial line in the San Joaquin Valley.

The federal issue was raised last week in a letter to the California High-Speed Rail Authority from Rep. Jeff Denham, a San Joaquin Valley Republican who chairs the House subcommittee on railroads.

Denham questioned why California had not sought approval of the project from the federal Surface Transportation Board, a successor to the old Interstate Commerce Commission, as apparently required by federal law.

With the CHSRA hoping to break ground within a few months, the failure to clear the project through the federal board, or get an exemption from it, could become a new weapon in the arsenal of groups that oppose the bullet train.

The sticky point, apparently, is the CHSRA's plan to connect the 131-mile-long San Joaquin Valley segment to Amtrak service in the region. The Surface Transportation Board exempted Florida's bullet train project from its process because it was a stand-alone system, but connecting to Amtrak could invoke its authority.

We're not sure yet," Dan Richard, the CHSRA's chairman, said earlier this week. But Tuesday, after meeting with Denham, the CHSRA agreed to seek the approval.

As that situation sorts itself out, bullet train critics are hammering on a provision of the voter-approved bond issue requiring the system, when complete, to carry passengers between San Francisco and Los Angeles in two hours and 40 minutes.

When the CHSRA switched the project from a stand-alone system to one "blended" with regional train service, critics demanded technical proof that it could meet the standard. Last month, the CHSRA generated a memorandum purporting to prove that it could do so "with appropriate assumptions," based on computer modeling.

However, the model assumes that the train could "operate safely at 220 mph on sustained steep grades" in the Tehachapi Mountains between Bakersfield and Los Angeles - a contention that critics are attacking as unrealistic and potentially unsafe.

That could become the basis for another legal challenge.

And, of course, there are still political impediments. Last week, speaking in Sacramento, Rep. Kevin McCarthy of Bakersfield, the third-ranking House leader, cautioned California against the "false belief" that more federal funds would be forthcoming.

"I would hate to see them start a process they cannot finish," McCarthy said.

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