RTD is building the FasTracks West Corridor light rail project with less money in its contingency fund than the Federal Transit Administration would like to see, making it urgent to manage the job with as few changes as possible, RTD officials said Friday.

The West Corridor’s current unallocated contingency of $32 million, out of the total project budget of $707.6 million, is the fund from which unexpected expenses will come in the next three and a half years. That amount is down from $44.3 million when the current project budget was set up last fall.

FTA, which is putting $308 million in a multi-year grant into the 12.1-mile light rail line from Denver to Golden, had RTD pushed for a contingency of $44 million. The minimum requirement for the project is $24.7 million.

“FTA has expressed concern about the limited contingency, and it will do an analysis of our budget this fall,” Rick Clarke, the acting chief of engineering for the FasTracks program, told a meeting this morning of West Corridor elected officials, local government staff and residents of the West Corridor.

“West Corridor is within budget but it’s very tight and it will be a challenge to keep working within that,” he said. “We have a relatively limited contingency to deal with things.”

Nevertheless, RTD has worked bigger projects with even less contingency. Its margin for error on the T-REX project was slimmer than for West Corridor. The light rail portion of T-REX, completed in 2006, was $941 million and ran on a contingency fund of $22 million. T-REX’s total contingency including the $814 million in highway expansion costs was $42 million, and it ended with $3.7 million left over.

T-REX also started out during a recession, which made budgeting and projecting a volatile exercise. The current recession is more volatile than the one in 2001.

However, Clarke noted, RTD now has signed contracts with its two general contractors, Denver Transit Construction Group and Balfour Beatty, with guaranteed maximum prices. That effectively insulates RTD from much volatility for the scope of the project already under contract. The remaining risks have been categorized into 20 areas of significance, with three of them considered high risk. Two of those three concern remaining unknowns over hazardous materials and soil contamination in demolition and excavation.

An excavator works on a retaining wall for the track bed at West Corridor's future Perry Street station.