A $75 million federal stimulus project to build 11 miles of railroad tracks near Quantico to relieve congestion for Virginia Railway Express, Amtrak and freight trains has stalled because of an ongoing feud that could derail the project.

The stimulus award was given in January 2010 to build a third track known as the Arkendale to Powell's Creek project. The segment eventually will be part of a longer high-speed rail line, but in the short term would relieve a key chokepoint on the adjacent lines.

But more than two years after the U.S. Department of Transportation issued the grant, it remains unbuilt. And the clock is ticking. The $75 million must be released by Sept. 30 or the money is lost, returned to the pool of stimulus funds.

Various agencies are pointing fingers at each other for who is to blame.

The Federal Railroad Administration says the remaining negotiations are between Virginia officials and CSX Corp., the freight company that owns the rail line.

But Virginia Department of Rail and Public Transportation Director Thelma Drake said, "We do believe the disagreement is between the FRA and CSX."

Drake said Virginia officials haven't met with FRA officials since February 2011, and multiple meetings since have been canceled.

The fight hinges on what on-time performance standards trains traveling along the line should face and when such standards should take effect: when the segment is finished or when the entire third track from Fredericksburg to Washington is complete.

"We do have an agreement with CSX that Virginia is comfortable with," Drake said. "They've agreed to certain measures when our corridor is complete."

Ironically, the project was one of the best suited to get started, clearly "shovel ready" as required by the stimulus funding rules, said VRE spokesman Mark Roeber. The engineering and design work were already finished. Officials just needed the money.

"We will continue to work with all parties, including the federal government," CSX spokesman Bob Sullivan said.